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Fabian Frederick [Wed, 4 Jun 2014 23:12:14 +0000 (16:12 -0700)]
fs/binfmt_elf.c: fix bool assignements
Fix coccinelle warnings.
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fabian Frederick [Wed, 4 Jun 2014 23:12:13 +0000 (16:12 -0700)]
fs/efs: convert printk(KERN_DEBUG to pr_debug
All KERN_DEBUG callsites being under #ifdef DEBUG we can safely convert
everything to pr_debug without changing current behaviour.
Remove #ifdef DEBUG around pr_debugs only (suggested by Joe Perches)
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fabian Frederick [Wed, 4 Jun 2014 23:12:12 +0000 (16:12 -0700)]
fs/efs: add pr_fmt / use __func__
Also uniformize function arguments.
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fabian Frederick [Wed, 4 Jun 2014 23:12:11 +0000 (16:12 -0700)]
fs/efs: convert printk to pr_foo()
Convert all except KERN_DEBUG
(pr_debug doesn't work the same as printk(KERN_DEBUG and requires
special check)
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fabian Frederick [Wed, 4 Jun 2014 23:12:10 +0000 (16:12 -0700)]
scripts/checkpatch.pl: device_initcall is not the only __initcall substitute
This patch adds a link to init.h to find appropriate initcall function to
replace obsolete __initcall
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Joe Perches [Wed, 4 Jun 2014 23:12:10 +0000 (16:12 -0700)]
checkpatch: check stable email address
It should be stable@vger.kernel.org, not stable@kernel.org.
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Joe Perches [Wed, 4 Jun 2014 23:12:09 +0000 (16:12 -0700)]
checkpatch: warn on unnecessary void function return statements
void function lines that use a single tab then "return;" are generally
unnecessary.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Joe Perches [Wed, 4 Jun 2014 23:12:08 +0000 (16:12 -0700)]
checkpatch: prefer kstrto<foo> to sscanf(buf, "%<lhuidx>", &bar);
Use the kstrto<foo> functions in preference to sscanf.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Joe Perches [Wed, 4 Jun 2014 23:12:07 +0000 (16:12 -0700)]
checkpatch: add warning for kmalloc/kzalloc with multiply
Protect against sizeof overflows by preferring kmalloc_array/kcalloc over
kmalloc/kzalloc with a sizeof multiply.
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Joe Perches [Wed, 4 Jun 2014 23:12:06 +0000 (16:12 -0700)]
checkpatch: warn on #defines ending in semicolon
Using a #define ending in a semicolon is poor style and can lead to
unexpected code paths being executed.
Warn on uses of these #define types:
#define foo[(...)] bar;
#define foo[(...)] \
bar;
Based on a patch from Borislav Petkov.
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Joe Perches [Wed, 4 Jun 2014 23:12:05 +0000 (16:12 -0700)]
checkpatch: make --strict a default for files in drivers/net and net/
Networking files are generally more strictly conformant to linux-kernel
style so make checkpatch more verbose by default for patches to files or
when checking files in these directories.
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Joe Perches [Wed, 4 Jun 2014 23:12:04 +0000 (16:12 -0700)]
checkpatch: always warn on missing blank line after variable declaration block
Make the test system wide, modify the message too.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rob Herring [Wed, 4 Jun 2014 23:12:03 +0000 (16:12 -0700)]
checkpatch: fix wildcard DT compatible string checking
We attempt to search for compatible strings which use a variable token in
the documented name such as <chip> or <soc>. While this was attempted to
be handled, it's utterly broken.
The desired forms of matching are:
vendor,<chip>-*
vendor,name<part#>-*
For <chip>, lower case characters and numbers are permitted. For <part#>,
only numeric values are allowed.
With this change, the number of missing compatible strings reported in
arch/arm/boot/dts is reduced from 1071 to 960.
Reported-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Florian Vaussard <florian.vaussard@epfl.ch>
Cc: Joe Perches <joe@perches.com>
Cc: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fabian Frederick [Wed, 4 Jun 2014 23:12:02 +0000 (16:12 -0700)]
kernel/compat.c: use sizeof() instead of sizeof
Fix 4 checkpatch warnings
WARNING: sizeof *tv should be sizeof(*tv)
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fabian Frederick [Wed, 4 Jun 2014 23:12:01 +0000 (16:12 -0700)]
lib/asn1_decoder.c: kernel-doc warning fix
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fabian Frederick [Wed, 4 Jun 2014 23:12:00 +0000 (16:12 -0700)]
lib/atomic64_test.c: convert printk(KERN_INFO to pr_info
Convert printk to current pr_foo() logging functions.
Also add pr_fmt based on KBUILD_MODNAME to avoid repeating prefix. Prefix
is now "atomic64_test: "
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Luca Barbieri <luca@luca-barbieri.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fabian Frederick [Wed, 4 Jun 2014 23:11:59 +0000 (16:11 -0700)]
lib/bug.c: convert printk to pr_foo()
- Coalesce formats
- "WARNING:" prefix unchanged to keep bug format.
- printk(KERN_DEFAULT not converted.
- define pr_fmt without prefix to avoid any default prefix update
(suggested by Joe Perches).
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fabian Frederick [Wed, 4 Jun 2014 23:11:58 +0000 (16:11 -0700)]
lib/textsearch.c: move EXPORT_SYMBOL after functions
Fix checkpatch warning:
"WARNING: EXPORT_SYMBOL(foo); should immediately follow its function/variable"
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fabian Frederick [Wed, 4 Jun 2014 23:11:57 +0000 (16:11 -0700)]
lib/nlattr.c: move EXPORT_SYMBOL after functions
Fix some checkpatch warnings:
WARNING: EXPORT_SYMBOL(foo); should immediately follow its function/variable
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Pablo Neira <pablo@netfilter.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fabian Frederick [Wed, 4 Jun 2014 23:11:57 +0000 (16:11 -0700)]
lib/digsig.c: kernel-doc warning fixes
Small typo and @return: -> Returns ...
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Duan Jiong <duanj.fnst@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fabian Frederick [Wed, 4 Jun 2014 23:11:56 +0000 (16:11 -0700)]
lib/crc32.c: remove unnecessary __constant
Use cpu_to_le32 instead of __constant_cpu_to_le32.
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fabian Frederick [Wed, 4 Jun 2014 23:11:55 +0000 (16:11 -0700)]
lib/radix-tree.c: kernel-doc warning fix
index has been removed from __radix_tree_delete_node in
449dd6984d0e47
("mm: keep page cache radix tree nodes in check")
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Dan Streetman [Wed, 4 Jun 2014 23:11:54 +0000 (16:11 -0700)]
lib/plist.c: make CONFIG_DEBUG_PI_LIST selectable
Change CONFIG_DEBUG_PI_LIST to be user-selectable, and add a title and
description. Remove the dependency on DEBUG_RT_MUTEXES since they were
changed to use rbtrees, and there are other users of plists now.
Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Minfei Huang [Wed, 4 Jun 2014 23:11:53 +0000 (16:11 -0700)]
lib/btree.c: fix leak of whole btree nodes
I use btree from 3.14-rc2 in my own module. When the btree module is
removed, a warning arises:
kmem_cache_destroy btree_node: Slab cache still has objects
CPU: 13 PID: 9150 Comm: rmmod Tainted: GF O 3.14.0-rc2 #1
Hardware name: Inspur NF5270M3/NF5270M3, BIOS CHEETAH_2.1.3 09/10/2013
Call Trace:
dump_stack+0x49/0x5d
kmem_cache_destroy+0xcf/0xe0
btree_module_exit+0x10/0x12 [btree]
SyS_delete_module+0x198/0x1f0
system_call_fastpath+0x16/0x1b
The cause is that it doesn't release the last btree node, when height = 1
and fill = 1.
[akpm@linux-foundation.org: remove unneeded test of NULL]
Signed-off-by: Minfei Huang <huangminfei@ucloud.cn>
Cc: Joern Engel <joern@logfs.org>
Cc: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fabian Frederick [Wed, 4 Jun 2014 23:11:52 +0000 (16:11 -0700)]
lib/vsprintf.c: fix comparison to bool
Fixing 2 coccinelle warnings:
lib/vsprintf.c:2350:2-9: WARNING: Assignment of bool to 0/1
lib/vsprintf.c:2389:3-10: WARNING: Assignment of bool to 0/1
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fabian Frederick [Wed, 4 Jun 2014 23:11:51 +0000 (16:11 -0700)]
lib/libcrc32c.c: use PTR_ERR_OR_ZERO
replace IS_ERR/PTR_ERR
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Lasse Collin [Wed, 4 Jun 2014 23:11:50 +0000 (16:11 -0700)]
lib/xz: enable all filters by default in Kconfig
This restores the old behavior that existed before 2013-02-22, when
changes were made by
64dbfb444c150 ("decompressors: drop dependency on
CONFIG_EXPERT") and
5dc49c75a2 ("decompressors: make the default
XZ_DEC_* config match the selected architecture").
Disabling the filters only makes sense on embedded systems.
Signed-off-by: Lasse Collin <lasse.collin@tukaani.org>
Acked-by: Kyle McMartin <kyle@infradead.org>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Phillip Lougher <phillip@lougher.demon.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Dan Streetman [Wed, 4 Jun 2014 23:11:49 +0000 (16:11 -0700)]
lib/plist.c: replace pr_debug with printk in plist_test()
Replace pr_debug() in lib/plist.c test function plist_test() with
printk(KERN_DEBUG ...).
Without DEBUG defined, pr_debug() is complied out, but the entire
plist_test() function is already inside CONFIG_DEBUG_PI_LIST, so printk
should just be used directly.
Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Lasse Collin [Wed, 4 Jun 2014 23:11:48 +0000 (16:11 -0700)]
lib/xz: add comments for the intentionally missing break statements
Signed-off-by: Lasse Collin <lasse.collin@tukaani.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Dan Carpenter [Wed, 4 Jun 2014 23:11:47 +0000 (16:11 -0700)]
lib/string.c: use the name "C-string" in comments
For strncpy() and friends the source string may or may not have an actual
NUL character at the end. The documentation is confusing in this because
it specifically mentions that you are passing a "NUL-terminated" string.
Wikipedia says that "C-string" is an alternative name we can use instead.
http://en.wikipedia.org/wiki/Null-terminated_string
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Borislav Petkov [Wed, 4 Jun 2014 23:11:46 +0000 (16:11 -0700)]
kernel/printk: use symbolic defines for console loglevels
... instead of naked numbers.
Stuff in sysrq.c used to set it to 8 which is supposed to mean above
default level so set it to DEBUG instead as we're terminating/killing all
tasks and we want to be verbose there.
Also, correct the check in x86_64_start_kernel which should be >= as
we're clearly issuing the string there for all debug levels, not only
the magical 10.
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Joe Perches <joe@perches.com>
Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Will Deacon [Wed, 4 Jun 2014 23:11:45 +0000 (16:11 -0700)]
printk: report dropping of messages from logbuf
If the log ring buffer becomes full, we silently overwrite old messages
with new data. console_unlock will detect this case and fast-forward the
console_* pointers to skip over the corrupted data, but nothing will be
reported to the user.
This patch hijacks the first valid log message after detecting that we
dropped messages and prefixes it with a note detailing how many messages
were dropped. For long (~1000 char) messages, this will result in some
truncation of the real message, but given that we're dropping things
anyway, that doesn't seem to be the end of the world.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Kay Sievers <kay@vrfy.org>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Dan Streetman [Wed, 4 Jun 2014 23:11:44 +0000 (16:11 -0700)]
Documentation: expand/clarify debug documentation
The pr_debug() and related debug print macros all differ from the normal
pr_XXX() macros, in that the normal ones print unconditionally, while
the debug macros are compiled out unless DEBUG is defined or
CONFIG_DYNAMIC_DEBUG is set. This isn't obvious, and the only way to
find this out is either to review the actual printk.h code or to read
CodingStyle, and the message there doesn't highlight the fact.
Change Documentation/CodingStyle to clearly indicate that pr_debug() and
related debug printing macros behave differently than all other pr_XXX()
macros, and attempt to clarify when and where the different debug
printing methods might be used.
Add short comment to printk.h above the pr_XXX() macros indicating that
while these macros print unconditionally, pr_debug() does not.
Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Cc: Joe Perches <joe@perches.com>
Cc: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
John Stultz [Wed, 4 Jun 2014 23:11:43 +0000 (16:11 -0700)]
timekeeping: use printk_deferred when holding timekeeping seqlock
Jiri Bohac pointed out that there are rare but potential deadlock
possibilities when calling printk while holding the timekeeping
seqlock.
This is due to printk() triggering console sem wakeup, which can
cause scheduling code to trigger hrtimers which may try to read
the time.
Specifically, as Jiri pointed out, that path is:
printk
vprintk_emit
console_unlock
up(&console_sem)
__up
wake_up_process
try_to_wake_up
ttwu_do_activate
ttwu_activate
activate_task
enqueue_task
enqueue_task_fair
hrtick_update
hrtick_start_fair
hrtick_start_fair
get_time
ktime_get
--> endless loop on
read_seqcount_retry(&timekeeper_seq, ...)
This patch tries to avoid this issue by using printk_deferred (previously
named printk_sched) which should defer printing via a irq_work_queue.
Signed-off-by: John Stultz <john.stultz@linaro.org>
Reported-by: Jiri Bohac <jbohac@suse.cz>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
John Stultz [Wed, 4 Jun 2014 23:11:41 +0000 (16:11 -0700)]
printk: Add printk_deferred_once
Two of the three prink_deferred uses are really printk_once style
uses, so add a printk_deferred_once macro to simplify those call
sites.
Signed-off-by: John Stultz <john.stultz@linaro.org>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jiri Bohac <jbohac@suse.cz>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
John Stultz [Wed, 4 Jun 2014 23:11:40 +0000 (16:11 -0700)]
printk: rename printk_sched to printk_deferred
After learning we'll need some sort of deferred printk functionality in
the timekeeping core, Peter suggested we rename the printk_sched function
so it can be reused by needed subsystems.
This only changes the function name. No logic changes.
Signed-off-by: John Stultz <john.stultz@linaro.org>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jiri Bohac <jbohac@suse.cz>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
John Stultz [Wed, 4 Jun 2014 23:11:39 +0000 (16:11 -0700)]
printk: disable preemption for printk_sched
An earlier change in -mm (printk: remove separate printk_sched
buffers...), removed the printk_sched irqsave/restore lines since it was
safe for current users. Since we may be expanding usage of
printk_sched(), disable preepmtion for this function to make it more
generally safe to call.
Signed-off-by: John Stultz <john.stultz@linaro.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jiri Bohac <jbohac@suse.cz>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Steven Rostedt [Wed, 4 Jun 2014 23:11:38 +0000 (16:11 -0700)]
printk: remove separate printk_sched buffers and use printk buf instead
To prevent deadlocks with doing a printk inside the scheduler,
printk_sched() was created. The issue is that printk has a console_sem
that it can grab and release. The release does a wake up if there's a
task pending on the sem, and this wake up grabs the rq locks that is
held in the scheduler. This leads to a possible deadlock if the wake up
uses the same rq as the one with the rq lock held already.
What printk_sched() does is to save the printk write in a per cpu buffer
and sets the PRINTK_PENDING_SCHED flag. On a timer tick, if this flag is
set, the printk() is done against the buffer.
There's a couple of issues with this approach.
1) If two printk_sched()s are called before the tick, the second one
will overwrite the first one.
2) The temporary buffer is 512 bytes and is per cpu. This is a quite a
bit of space wasted for something that is seldom used.
In order to remove this, the printk_sched() can use the printk buffer
instead, and delay the console_trylock()/console_unlock() to the queued
work.
Because printk_sched() would then be taking the logbuf_lock, the
logbuf_lock must not be held while doing anything that may call into the
scheduler functions, which includes wake ups. Unfortunately, printk()
also has a console_sem that it uses, and on release, the up(&console_sem)
may do a wake up of any pending waiters. This must be avoided while
holding the logbuf_lock.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Kara [Wed, 4 Jun 2014 23:11:37 +0000 (16:11 -0700)]
printk: enable interrupts before calling console_trylock_for_printk()
We need interrupts disabled when calling console_trylock_for_printk()
only so that cpu id we pass to can_use_console() remains valid (for
other things console_sem provides all the exclusion we need and
deadlocks on console_sem due to interrupts are impossible because we use
down_trylock()). However if we are rescheduled, we are guaranteed to
run on an online cpu so we can easily just get the cpu id in
can_use_console().
We can lose a bit of performance when we enable interrupts in
vprintk_emit() and then disable them again in console_unlock() but OTOH
it can somewhat reduce interrupt latency caused by console_unlock()
especially since later in the patch series we will want to spin on
console_sem in console_trylock_for_printk().
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Kara [Wed, 4 Jun 2014 23:11:36 +0000 (16:11 -0700)]
printk: fix lockdep instrumentation of console_sem
Printk calls mutex_acquire() / mutex_release() by hand to instrument
lockdep about console_sem. However in some corner cases the
instrumentation is missing. Fix the problem by creating helper functions
for locking / unlocking console_sem which take care of lockdep
instrumentation as well.
Signed-off-by: Jan Kara <jack@suse.cz>
Reported-by: Fabio Estevam <festevam@gmail.com>
Reported-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Fabio Estevam <fabio.estevam@freescale.com>
Tested-By: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Kara [Wed, 4 Jun 2014 23:11:35 +0000 (16:11 -0700)]
printk: release lockbuf_lock before calling console_trylock_for_printk()
There's no reason to hold lockbuf_lock when entering
console_trylock_for_printk().
The first thing this function does is to call down_trylock(console_sem)
and if that fails it immediately unlocks lockbuf_lock. So lockbuf_lock
isn't needed for that branch. When down_trylock() succeeds, the rest of
console_trylock() is OK without lockbuf_lock (it is called without it
from other places), and the only remaining thing in
console_trylock_for_printk() is can_use_console() call. For that call
console_sem is enough (it iterates all consoles and checks CON_ANYTIME
flag).
So we drop logbuf_lock before entering console_trylock_for_printk() which
simplifies the code.
[akpm@linux-foundation.org: fix have_callable_console() comment]
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Kara [Wed, 4 Jun 2014 23:11:34 +0000 (16:11 -0700)]
printk: remove outdated comment
Comment about interesting interlocking between lockbuf_lock and
console_sem is outdated.
It was added in 2002 by commit
a880f45a48be during conversion of
console_lock to console_sem + lockbuf_lock.
At that time release_console_sem() (today's equivalent is
console_unlock()) was indeed using lockbuf_lock to avoid races between
trylock on console_sem in printk() and unlock of console_sem. However
these days the interlocking is gone and the races are avoided by
rechecking logbuf state after releasing console_sem.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Petr Mladek [Wed, 4 Jun 2014 23:11:33 +0000 (16:11 -0700)]
printk: return really stored message length
I wonder if anyone uses printk return value but it is there and should be
counted correctly.
This patch modifies log_store() to return the number of really stored
bytes from the 'text' part. Also it handles the return value in
vprintk_emit().
Note that log_store() is used also in cont_flush() but we could ignore the
return value there. The function works with characters that were already
counted earlier. In addition, the store could newer fail here because the
length of the printed text is limited by the "cont" buffer and "dict" is
NULL.
Signed-off-by: Petr Mladek <pmladek@suse.cz>
Cc: Jan Kara <jack@suse.cz>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Kay Sievers <kay@vrfy.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Petr Mladek [Wed, 4 Jun 2014 23:11:32 +0000 (16:11 -0700)]
printk: shrink too long messages
We might want to print at least part of too long messages and add some
warning for debugging purpose.
The question is how long the shrunken message should be. If we use the
whole buffer, it might get rotated too soon. Let's try to use only 1/4 of
the buffer for now.
Also shrink the whole dictionary. We do not want to parse it or break it
in the middle of some pair of values. It would not cause any real harm
but still.
Signed-off-by: Petr Mladek <pmladek@suse.cz>
Cc: Jan Kara <jack@suse.cz>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Kay Sievers <kay@vrfy.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Petr Mladek [Wed, 4 Jun 2014 23:11:31 +0000 (16:11 -0700)]
printk: split message size computation
We will want to recompute the message size when shrinking too long
messages. Let's put the code into separate function.
The side effect of setting "pad_len" is not nice but it is worth removing
the code duplication. Note that I will probably have one more usage for
this function when handling messages safe way in NMI context.
This patch does not change the existing behavior.
Signed-off-by: Petr Mladek <pmladek@suse.cz>
Cc: Jan Kara <jack@suse.cz>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Kay Sievers <kay@vrfy.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Petr Mladek [Wed, 4 Jun 2014 23:11:30 +0000 (16:11 -0700)]
printk: ignore too long messages
There was no check for too long messages. The check for free space always
passed when first_seq and next_seq were equal. Enough free space was not
guaranteed, though.
log_store() might be called to store messages up to 64kB + 64kB + 16B.
This is sum of maximal text_len, dict_len values, and the size of the
structure printk_log.
On the other hand, the minimal size for the main log buffer currently is
4kB and it is enforced only by Kconfig.
The good news is that the usage looks safe right now. log_store() is
called only from vprintk_emit() and cont_flush(). Here the "text" part is
always passed via a static buffer and the length is limited to
LOG_LINE_MAX which is 1024. The "dict" part is NULL in most cases. The
only exceptions is when vprintk_emit() is called from printk_emit() and
dev_vprintk_emit(). But printk_emit() is currently used only in
devkmsg_writev() and here "dict" is NULL as well. In dev_vprintk_emit(),
"dict" is limited by the static buffer "hdr" of the size 128 bytes. It
meas that the current maximal printed text is 1024B + 128B + 16B and it
always fit the log buffer.
But it is only matter of time when someone calls printk_emit() with unsafe
parameters, especially the "dict" one.
This patch adds a check for the free space when the buffer is empty. It
reuses the already existing log_has_space() function but it has to add an
extra parameter. It defines whether the buffer is empty. Note that the
same values of "first_idx" and "next_idx" might also mean that the buffer
is full.
If the buffer is empty, we must respect the current position of the
indexes. We cannot reset them to the beginning of the buffer. Otherwise,
the functions reading the buffer would get crazy.
The question is what to do when the message is too long. This patch uses
the easiest solution and just ignores the problematic message. Let's do
something better in a followup patch.
Signed-off-by: Petr Mladek <pmladek@suse.cz>
Cc: Jan Kara <jack@suse.cz>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Kay Sievers <kay@vrfy.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Petr Mladek [Wed, 4 Jun 2014 23:11:28 +0000 (16:11 -0700)]
printk: split code for making free space in the log buffer
The check for free space in the log buffer always passes when "first_seq"
and "next_seq" are equal. In theory, it might cause writing outside of
the log buffer.
Fortunately, the current usage looks safe because the used "text" and
"dict" buffers are quite limited. See the second patch for more details.
Anyway, it is better to be on the safe side and add a check. An easy
solution is done in the 2nd patch and it is improved in the 4th patch.
5th patch fixes the computation of the printed message length.
1st and 3rd patches just do some code refactoring to make the other
patches easier.
This patch (of 5):
There will be needed some fixes in the check for free space. They will be
easier if the code is moved outside of the quite long log_store()
function.
This patch does not change the existing behavior.
Signed-off-by: Petr Mladek <pmladek@suse.cz>
Cc: Jan Kara <jack@suse.cz>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Kay Sievers <kay@vrfy.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Kirill A. Shutemov [Wed, 4 Jun 2014 23:11:27 +0000 (16:11 -0700)]
kernel/user.c: drop unused field 'files' from user_struct
Nobody seems uses it for a long time. Let's drop it.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fabian Frederick [Wed, 4 Jun 2014 23:11:26 +0000 (16:11 -0700)]
kernel/hung_task.c: convert simple_strtoul to kstrtouint
sysctl_hung_task_panic has been changed to unsigned int. use kstrtouint
instead of obsolete simple_strtoul
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fabian Frederick [Wed, 4 Jun 2014 23:11:26 +0000 (16:11 -0700)]
kernel/utsname_sysctl.c: replace obsolete __initcall by device_initcall
Also fixes checkpatch warnings on proc_dostring function parameters
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fabian Frederick [Wed, 4 Jun 2014 23:11:25 +0000 (16:11 -0700)]
kernel/reboot.c: convert simple_strtoul to kstrtoint
Replace obsolete function.
kstrtoint is used as reboot_cpu is an integer.
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fabian Frederick [Wed, 4 Jun 2014 23:11:24 +0000 (16:11 -0700)]
kernel/res_counter.c: replace simple_strtoull by kstrtoull
[akpm@linux-foundation.org: don't overwrite kstrtoull()'s errno]
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fabian Frederick [Wed, 4 Jun 2014 23:11:23 +0000 (16:11 -0700)]
kernel/tracepoint.c: kernel-doc fixes
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fabian Frederick [Wed, 4 Jun 2014 23:11:22 +0000 (16:11 -0700)]
kernel/stop_machine.c: kernel-doc warning fix
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fabian Frederick [Wed, 4 Jun 2014 23:11:21 +0000 (16:11 -0700)]
kernel/latencytop.c: convert seq_printf to seq_puts
This patch also fixes one function declaration over 80 characters.
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fabian Frederick [Wed, 4 Jun 2014 23:11:20 +0000 (16:11 -0700)]
kernel/exec_domain.c: code clean-up
Fix checkpatch warnings about EXPORT_SYMBOL and return()
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fabian Frederick [Wed, 4 Jun 2014 23:11:19 +0000 (16:11 -0700)]
kernel/capability.c: code clean-up
- EXPORT_SYMBOL
- typo: unexpectidly->unexpectedly
- function prototype over 80 characters
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fabian Frederick [Wed, 4 Jun 2014 23:11:18 +0000 (16:11 -0700)]
kernel/backtracetest.c: replace no level printk by pr_info()
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fabian Frederick [Wed, 4 Jun 2014 23:11:17 +0000 (16:11 -0700)]
kernel/cpu.c: convert printk to pr_foo()
no level printk converted to pr_warn (if err)
no level printk converted to pr_info (disabling non-boot cpus)
Other printk converted to respective level.
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
James Hogan [Wed, 4 Jun 2014 23:11:16 +0000 (16:11 -0700)]
compiler.h: avoid sparse errors in __compiletime_error_fallback()
Usually, BUG_ON and friends aren't even evaluated in sparse, but recently
compiletime_assert_atomic_type() was added, and that now results in a
sparse warning every time it is used.
The reason turns out to be the temporary variable, after it sparse no
longer considers the value to be a constant, and results in a warning and
an error. The error is the more annoying part of this as it suppresses
any further warnings in the same file, hiding other problems.
Unfortunately the condition cannot be simply expanded out to avoid the
temporary variable since it breaks compiletime_assert on old versions of
GCC such as GCC 4.2.4 which the latest metag compiler is based on.
Therefore #ifndef __CHECKER__ out the __compiletime_error_fallback which
uses the potentially negative size array to trigger a conditional compiler
error, so that sparse doesn't see it.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Johannes Berg <johannes.berg@intel.com>
Cc: Daniel Santos <daniel.santos@pobox.com>
Cc: Luciano Coelho <luciano.coelho@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fabian Frederick [Wed, 4 Jun 2014 23:11:15 +0000 (16:11 -0700)]
fs/exportfs/expfs.c: kernel-doc warning fixes
Fixing 2 typo in function comments.
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "J. Bruce Fields" <bfields@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fabian Frederick [Wed, 4 Jun 2014 23:11:14 +0000 (16:11 -0700)]
fs/efivarfs/super.c: use static const for dentry_operations
...like other filesystems.
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Matthew Garrett <matthew.garrett@nebula.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fabian Frederick [Wed, 4 Jun 2014 23:11:12 +0000 (16:11 -0700)]
sys_sgetmask/sys_ssetmask: add CONFIG_SGETMASK_SYSCALL
sys_sgetmask and sys_ssetmask are obsolete system calls no longer
supported in libc.
This patch replaces architecture related __ARCH_WANT_SYS_SGETMAX by expert
mode configuration.That option is enabled by default for those
architectures.
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Steven Miao <realmz6@gmail.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Greg Ungerer <gerg@uclinux.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Eric Dumazet [Wed, 4 Jun 2014 23:11:11 +0000 (16:11 -0700)]
mm/zswap: NUMA aware allocation for zswap_dstmem
zswap_dstmem is a percpu block of memory, which should be allocated using
kmalloc_node(), to get better NUMA locality.
Without it, all the blocks are allocated from a single node.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Seth Jennings <sjennings@variantweb.net>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Minchan Kim [Wed, 4 Jun 2014 23:11:10 +0000 (16:11 -0700)]
mm/zsmalloc: make zsmalloc module-buildable
Now, we can build zsmalloc as module because unmap_kernel_range was
exported.
Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Jerome Marchand <jmarchan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Minchan Kim [Wed, 4 Jun 2014 23:11:09 +0000 (16:11 -0700)]
mm/vmalloc.c: export unmap_kernel_range()
zsmalloc needs exported unmap_kernel_range for building as a module. See
https://lkml.org/lkml/2013/1/18/487
I didn't send a patch to make unmap_kernel_range exportable at that time
because zram was staging stuff and I thought VM function exporting for
staging stuff makes no sense.
Now zsmalloc was promoted. If we can't build zsmalloc as module, it means
we can't build zram as module, either. Additionally, buddy map_vm_area is
already exported so let's export unmap_kernel_range to help his buddy.
Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Jerome Marchand <jmarchan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Weijie Yang [Wed, 4 Jun 2014 23:11:08 +0000 (16:11 -0700)]
zsmalloc: fixup trivial zs size classes value in comments
According to calculation, ZS_SIZE_CLASSES value is 255 on systems with 4K
page size, not 254. The old value may forget count the ZS_MIN_ALLOC_SIZE
in.
This patch fixes this trivial issue in the comments.
Signed-off-by: Weijie Yang <weijie.yang@samsung.com>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fabian Frederick [Wed, 4 Jun 2014 23:11:07 +0000 (16:11 -0700)]
mm/zbud.c: make size unsigned like unique callsite
zbud_alloc is only called by zswap_frontswap_store with unsigned int len.
Change function parameter + update >= 0 check.
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Acked-by: Seth Jennings <sjennings@variantweb.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Weijie Yang [Wed, 4 Jun 2014 23:11:06 +0000 (16:11 -0700)]
zram: correct offset usage in zram_bio_discard
We want to skip the physical block(PAGE_SIZE) which is partially covered
by the discard bio, so we check the remaining size and subtract it if
there is a need to goto the next physical block.
The current offset usage in zram_bio_discard is incorrect, it will cause
its upper filesystem breakdown. Consider the following scenario:
On some architecture or config, PAGE_SIZE is 64K for example, filesystem
is set up on zram disk without PAGE_SIZE aligned, a discard bio leads to a
offset = 4K and size=72K, normally, it should not really discard any
physical block as it partially cover two physical blocks. However, with
the current offset usage, it will discard the second physical block and
free its memory, which will cause filesystem breakdown.
This patch corrects the offset usage in zram_bio_discard.
Signed-off-by: Weijie Yang <weijie.yang@samsung.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Acked-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Bob Liu <bob.liu@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Hugh Dickins [Wed, 4 Jun 2014 23:11:04 +0000 (16:11 -0700)]
mm, memcg: periodically schedule when emptying page list
mem_cgroup_force_empty_list() can iterate a large number of pages on an
lru and mem_cgroup_move_parent() doesn't return an errno unless certain
criteria, none of which indicate that the iteration may be taking too
long, is met.
We have encountered the following stack trace many times indicating
"need_resched set for >
51000020 ns (51 ticks) without schedule", for
example:
scheduler_tick()
<timer irq>
mem_cgroup_move_account+0x4d/0x1d5
mem_cgroup_move_parent+0x8d/0x109
mem_cgroup_reparent_charges+0x149/0x2ba
mem_cgroup_css_offline+0xeb/0x11b
cgroup_offline_fn+0x68/0x16b
process_one_work+0x129/0x350
If this iteration is taking too long, we still need to do cond_resched()
even when an individual page is not busy.
[rientjes@google.com: changelog]
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Denys Vlasenko [Wed, 4 Jun 2014 23:11:03 +0000 (16:11 -0700)]
Documentation/sysctl/vm.txt: clarify vfs_cache_pressure description
Existing description is worded in a way which almost encourages setting of
vfs_cache_pressure above 100, possibly way above it.
Users are left in a dark what this numeric value is - an int? a
percentage? what the scale is?
As a result, we are getting reports about noticeable performance
degradation from users who have set vfs_cache_pressure to ridiculously
high values - because they thought there is no downside to it.
Via code inspection it's obvious that this value is treated as a
percentage. This patch changes text to reflect this fact, and adds a
cautionary paragraph advising against setting vfs_cache_pressure sky high.
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Naoya Horiguchi [Wed, 4 Jun 2014 23:11:02 +0000 (16:11 -0700)]
mm/memory-failure.c: support use of a dedicated thread to handle SIGBUS(BUS_MCEERR_AO)
Currently memory error handler handles action optional errors in the
deferred manner by default. And if a recovery aware application wants
to handle it immediately, it can do it by setting PF_MCE_EARLY flag.
However, such signal can be sent only to the main thread, so it's
problematic if the application wants to have a dedicated thread to
handler such signals.
So this patch adds dedicated thread support to memory error handler. We
have PF_MCE_EARLY flags for each thread separately, so with this patch
AO signal is sent to the thread with PF_MCE_EARLY flag set, not the main
thread. If you want to implement a dedicated thread, you call prctl()
to set PF_MCE_EARLY on the thread.
Memory error handler collects processes to be killed, so this patch lets
it check PF_MCE_EARLY flag on each thread in the collecting routines.
No behavioral change for all non-early kill cases.
Tony said:
: The old behavior was crazy - someone with a multithreaded process might
: well expect that if they call prctl(PF_MCE_EARLY) in just one thread, then
: that thread would see the SIGBUS with si_code = BUS_MCEERR_A0 - even if
: that thread wasn't the main thread for the process.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Cc: Kamil Iskra <iskra@mcs.anl.gov>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Chen Gong <gong.chen@linux.jf.intel.com>
Cc: <stable@vger.kernel.org> [3.2+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Tony Luck [Wed, 4 Jun 2014 23:11:01 +0000 (16:11 -0700)]
mm/memory-failure.c: don't let collect_procs() skip over processes for MF_ACTION_REQUIRED
When Linux sees an "action optional" machine check (where h/w has reported
an error that is not in the current execution path) we generally do not
want to signal a process, since most processes do not have a SIGBUS
handler - we'd just prematurely terminate the process for a problem that
they might never actually see.
task_early_kill() decides whether to consider a process - and it checks
whether this specific process has been marked for early signals with
"prctl", or if the system administrator has requested early signals for
all processes using /proc/sys/vm/memory_failure_early_kill.
But for MF_ACTION_REQUIRED case we must not defer. The error is in the
execution path of the current thread so we must send the SIGBUS
immediatley.
Fix by passing a flag argument through collect_procs*() to
task_early_kill() so it knows whether we can defer or must take action.
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Chen Gong <gong.chen@linux.jf.intel.com>
Cc: <stable@vger.kernel.org> [3.2+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Tony Luck [Wed, 4 Jun 2014 23:10:59 +0000 (16:10 -0700)]
mm/memory-failure.c-failure: send right signal code to correct thread
When a thread in a multi-threaded application hits a machine check because
of an uncorrectable error in memory - we want to send the SIGBUS with
si.si_code = BUS_MCEERR_AR to that thread. Currently we fail to do that
if the active thread is not the primary thread in the process.
collect_procs() just finds primary threads and this test:
if ((flags & MF_ACTION_REQUIRED) && t == current) {
will see that the thread we found isn't the current thread and so send a
si.si_code = BUS_MCEERR_AO to the primary (and nothing to the active
thread at this time).
We can fix this by checking whether "current" shares the same mm with the
process that collect_procs() said owned the page. If so, we send the
SIGBUS to current (with code BUS_MCEERR_AR).
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Reported-by: Otto Bruggeman <otto.g.bruggeman@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Chen Gong <gong.chen@linux.jf.intel.com>
Cc: <stable@vger.kernel.org> [3.2+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jianyu Zhan [Wed, 4 Jun 2014 23:10:58 +0000 (16:10 -0700)]
mm/page-writeback.c: remove outdated comment
There is an orphaned prehistoric comment , which used to be against
get_dirty_limits(), the dawn of global_dirtyable_memory().
Back then, the implementation of get_dirty_limits() is complicated and
full of magic numbers, so this comment is necessary. But we now use the
clear and neat global_dirtyable_memory(), which renders this comment
ambiguous and useless. Remove it.
Signed-off-by: Jianyu Zhan <nasa4836@gmail.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Chen Yucong [Wed, 4 Jun 2014 23:10:57 +0000 (16:10 -0700)]
mm/swapfile.c: delete the "last_in_cluster < scan_base" loop in the body of scan_swap_map()
Via commit
ebc2a1a69111 ("swap: make cluster allocation per-cpu"), we
can find that all SWP_SOLIDSTATE "seek is cheap"(SSD case) has already
gone to si->cluster_info scan_swap_map_try_ssd_cluster() route. So that
the "last_in_cluster < scan_base" loop in the body of scan_swap_map()
has already become a dead code snippet, and it should have been deleted.
This patch is to delete the redundant loop as Hugh and Shaohua
suggested.
[hughd@google.com: fix comment, simplify code]
Signed-off-by: Chen Yucong <slaoub@gmail.com>
Cc: Shaohua Li <shli@kernel.org>
Acked-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Naoya Horiguchi [Wed, 4 Jun 2014 23:10:56 +0000 (16:10 -0700)]
hugetlb: rename hugepage_migration_support() to ..._supported()
We already have a function named hugepages_supported(), and the similar
name hugepage_migration_support() is a bit unconfortable, so let's rename
it hugepage_migration_supported().
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Kirill A. Shutemov [Wed, 4 Jun 2014 23:10:55 +0000 (16:10 -0700)]
mm: document do_fault_around() feature
Some clarification on how faultaround works.
[akpm@linux-foundation.org: tweak comment text]
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Kirill A. Shutemov [Wed, 4 Jun 2014 23:10:54 +0000 (16:10 -0700)]
mm: nominate faultaround area in bytes rather than page order
There is evidencs that the faultaround feature is less relevant on
architectures with page size bigger then 4k. Which makes sense since page
fault overhead per byte of mapped area should be less there.
Let's rework the feature to specify faultaround area in bytes instead of
page order. It's 64 kilobytes for now.
The patch effectively disables faultaround on architectures with page size
>= 64k (like ppc64).
It's possible that some other size of faultaround area is relevant for a
platform. We can expose `fault_around_bytes' variable to arch-specific
code once such platforms will be found.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Hugh Dickins <hughd@google.com>
Cc: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Zhang Zhen [Wed, 4 Jun 2014 23:10:53 +0000 (16:10 -0700)]
mm/page_alloc.c: cleanup add_active_range() related comments
add_active_range() has been repalced by memblock_set_node(). Clean up the
comments to comply with that change.
Signed-off-by: Zhang Zhen <zhenzhang.zhang@huawei.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Konstantin Khlebnikov [Wed, 4 Jun 2014 23:10:52 +0000 (16:10 -0700)]
mm/rmap.c: cleanup ttu_flags
Transform action part of ttu_flags into individiual bits. These flags
aren't part of any uses-space visible api or even trace events.
Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Konstantin Khlebnikov [Wed, 4 Jun 2014 23:10:51 +0000 (16:10 -0700)]
mm/rmap.c: don't call mmu_notifier_invalidate_page() during munlock
In its munmap mode, try_to_unmap_one() searches other mlocked vmas, it
never unmaps pages. There is no reason for invalidation because ptes are
left unchanged.
Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Konstantin Khlebnikov [Wed, 4 Jun 2014 23:10:50 +0000 (16:10 -0700)]
mm/process_vm_access: move config option into init/Kconfig
CONFIG_CROSS_MEMORY_ATTACH adds couple syscalls: process_vm_readv and
process_vm_writev, it's a kind of IPC for copying data between processes.
Currently this option is placed inside "Processor type and features".
This patch moves it into "General setup" (where all other arch-independed
syscalls and ipc features are placed) and changes prompt string to less
cryptic.
Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Christopher Yeoh <cyeoh@au1.ibm.com>
Cc: Davidlohr Bueso <davidlohr@hp.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mel Gorman [Wed, 4 Jun 2014 23:10:49 +0000 (16:10 -0700)]
mm: vmscan: use proportional scanning during direct reclaim and full scan at DEF_PRIORITY
Commit "mm: vmscan: obey proportional scanning requirements for kswapd"
ensured that file/anon lists were scanned proportionally for reclaim from
kswapd but ignored it for direct reclaim. The intent was to minimse
direct reclaim latency but Yuanhan Liu pointer out that it substitutes one
long stall for many small stalls and distorts aging for normal workloads
like streaming readers/writers. Hugh Dickins pointed out that a
side-effect of the same commit was that when one LRU list dropped to zero
that the entirety of the other list was shrunk leading to excessive
reclaim in memcgs. This patch scans the file/anon lists proportionally
for direct reclaim to similarly age page whether reclaimed by kswapd or
direct reclaim but takes care to abort reclaim if one LRU drops to zero
after reclaiming the requested number of pages.
Based on ext4 and using the Intel VM scalability test
3.15.0-rc5 3.15.0-rc5
shrinker proportion
Unit lru-file-readonce elapsed 5.3500 ( 0.00%) 5.4200 ( -1.31%)
Unit lru-file-readonce time_range 0.2700 ( 0.00%) 0.1400 ( 48.15%)
Unit lru-file-readonce time_stddv 0.1148 ( 0.00%) 0.0536 ( 53.33%)
Unit lru-file-readtwice elapsed 8.1700 ( 0.00%) 8.1700 ( 0.00%)
Unit lru-file-readtwice time_range 0.4300 ( 0.00%) 0.2300 ( 46.51%)
Unit lru-file-readtwice time_stddv 0.1650 ( 0.00%) 0.0971 ( 41.16%)
The test cases are running multiple dd instances reading sparse files. The results are within
the noise for the small test machine. The impact of the patch is more noticable from the vmstats
3.15.0-rc5 3.15.0-rc5
shrinker proportion
Minor Faults 35154 36784
Major Faults 611 1305
Swap Ins 394 1651
Swap Outs 4394 5891
Allocation stalls 118616 44781
Direct pages scanned
4935171 4602313
Kswapd pages scanned
15921292 16258483
Kswapd pages reclaimed
15913301 16248305
Direct pages reclaimed
4933368 4601133
Kswapd efficiency 99% 99%
Kswapd velocity 670088.047 682555.961
Direct efficiency 99% 99%
Direct velocity 207709.217 193212.133
Percentage direct scans 23% 22%
Page writes by reclaim 4858.000 6232.000
Page writes file 464 341
Page writes anon 4394 5891
Note that there are fewer allocation stalls even though the amount
of direct reclaim scanning is very approximately the same.
Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Tested-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Cc: Bob Liu <bob.liu@oracle.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Rik van Riel <riel@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Tim Chen [Wed, 4 Jun 2014 23:10:47 +0000 (16:10 -0700)]
fs/superblock: avoid locking counting inodes and dentries before reclaiming them
We remove the call to grab_super_passive in call to super_cache_count.
This becomes a scalability bottleneck as multiple threads are trying to do
memory reclamation, e.g. when we are doing large amount of file read and
page cache is under pressure. The cached objects quickly got reclaimed
down to 0 and we are aborting the cache_scan() reclaim. But counting
creates a log jam acquiring the sb_lock.
We are holding the shrinker_rwsem which ensures the safety of call to
list_lru_count_node() and s_op->nr_cached_objects. The shrinker is
unregistered now before ->kill_sb() so the operation is safe when we are
doing unmount.
The impact will depend heavily on the machine and the workload but for a
small machine using postmark tuned to use 4xRAM size the results were
3.15.0-rc5 3.15.0-rc5
vanilla shrinker-v1r1
Ops/sec Transactions 21.00 ( 0.00%) 24.00 ( 14.29%)
Ops/sec FilesCreate 39.00 ( 0.00%) 44.00 ( 12.82%)
Ops/sec CreateTransact 10.00 ( 0.00%) 12.00 ( 20.00%)
Ops/sec FilesDeleted 6202.00 ( 0.00%) 6202.00 ( 0.00%)
Ops/sec DeleteTransact 11.00 ( 0.00%) 12.00 ( 9.09%)
Ops/sec DataRead/MB 25.97 ( 0.00%) 29.10 ( 12.05%)
Ops/sec DataWrite/MB 49.99 ( 0.00%) 56.02 ( 12.06%)
ffsb running in a configuration that is meant to simulate a mail server showed
3.15.0-rc5 3.15.0-rc5
vanilla shrinker-v1r1
Ops/sec readall 9402.63 ( 0.00%) 9567.97 ( 1.76%)
Ops/sec create 4695.45 ( 0.00%) 4735.00 ( 0.84%)
Ops/sec delete 173.72 ( 0.00%) 179.83 ( 3.52%)
Ops/sec Transactions 14271.80 ( 0.00%) 14482.81 ( 1.48%)
Ops/sec Read 37.00 ( 0.00%) 37.60 ( 1.62%)
Ops/sec Write 18.20 ( 0.00%) 18.30 ( 0.55%)
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dave Chinner <david@fromorbit.com>
Tested-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Cc: Bob Liu <bob.liu@oracle.com>
Cc: Jan Kara <jack@suse.cz>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Dave Chinner [Wed, 4 Jun 2014 23:10:46 +0000 (16:10 -0700)]
fs/superblock: unregister sb shrinker before ->kill_sb()
This series is aimed at regressions noticed during reclaim activity. The
first two patches are shrinker patches that were posted ages ago but never
merged for reasons that are unclear to me. I'm posting them again to see
if there was a reason they were dropped or if they just got lost. Dave?
Time? The last patch adjusts proportional reclaim. Yuanhan Liu, can you
retest the vm scalability test cases on a larger machine? Hugh, does this
work for you on the memcg test cases?
Based on ext4, I get the following results but unfortunately my larger
test machines are all unavailable so this is based on a relatively small
machine.
postmark
3.15.0-rc5 3.15.0-rc5
vanilla proportion-v1r4
Ops/sec Transactions 21.00 ( 0.00%) 25.00 ( 19.05%)
Ops/sec FilesCreate 39.00 ( 0.00%) 45.00 ( 15.38%)
Ops/sec CreateTransact 10.00 ( 0.00%) 12.00 ( 20.00%)
Ops/sec FilesDeleted 6202.00 ( 0.00%) 6202.00 ( 0.00%)
Ops/sec DeleteTransact 11.00 ( 0.00%) 12.00 ( 9.09%)
Ops/sec DataRead/MB 25.97 ( 0.00%) 30.02 ( 15.59%)
Ops/sec DataWrite/MB 49.99 ( 0.00%) 57.78 ( 15.58%)
ffsb (mail server simulator)
3.15.0-rc5 3.15.0-rc5
vanilla proportion-v1r4
Ops/sec readall 9402.63 ( 0.00%) 9805.74 ( 4.29%)
Ops/sec create 4695.45 ( 0.00%) 4781.39 ( 1.83%)
Ops/sec delete 173.72 ( 0.00%) 177.23 ( 2.02%)
Ops/sec Transactions 14271.80 ( 0.00%) 14764.37 ( 3.45%)
Ops/sec Read 37.00 ( 0.00%) 38.50 ( 4.05%)
Ops/sec Write 18.20 ( 0.00%) 18.50 ( 1.65%)
dd of a large file
3.15.0-rc5 3.15.0-rc5
vanilla proportion-v1r4
WallTime DownloadTar 75.00 ( 0.00%) 61.00 ( 18.67%)
WallTime DD 423.00 ( 0.00%) 401.00 ( 5.20%)
WallTime Delete 2.00 ( 0.00%) 5.00 (-150.00%)
stutter (times mmap latency during large amounts of IO)
3.15.0-rc5 3.15.0-rc5
vanilla proportion-v1r4
Unit >5ms Delays 80252.0000 ( 0.00%) 81523.0000 ( -1.58%)
Unit Mmap min 8.2118 ( 0.00%) 8.3206 ( -1.33%)
Unit Mmap mean 17.4614 ( 0.00%) 17.2868 ( 1.00%)
Unit Mmap stddev 24.9059 ( 0.00%) 34.6771 (-39.23%)
Unit Mmap max 2811.6433 ( 0.00%) 2645.1398 ( 5.92%)
Unit Mmap 90% 20.5098 ( 0.00%) 18.3105 ( 10.72%)
Unit Mmap 93% 22.9180 ( 0.00%) 20.1751 ( 11.97%)
Unit Mmap 95% 25.2114 ( 0.00%) 22.4988 ( 10.76%)
Unit Mmap 99% 46.1430 ( 0.00%) 43.5952 ( 5.52%)
Unit Ideal Tput 85.2623 ( 0.00%) 78.8906 ( 7.47%)
Unit Tput min 44.0666 ( 0.00%) 43.9609 ( 0.24%)
Unit Tput mean 45.5646 ( 0.00%) 45.2009 ( 0.80%)
Unit Tput stddev 0.9318 ( 0.00%) 1.1084 (-18.95%)
Unit Tput max 46.7375 ( 0.00%) 46.7539 ( -0.04%)
This patch (of 3):
We will like to unregister the sb shrinker before ->kill_sb(). This will
allow cached objects to be counted without call to grab_super_passive() to
update ref count on sb. We want to avoid locking during memory
reclamation especially when we are skipping the memory reclaim when we are
out of cached objects.
This is safe because grab_super_passive does a try-lock on the
sb->s_umount now, and so if we are in the unmount process, it won't ever
block. That means what used to be a deadlock and races we were avoiding
by using grab_super_passive() is now:
shrinker umount
down_read(shrinker_rwsem)
down_write(sb->s_umount)
shrinker_unregister
down_write(shrinker_rwsem)
<blocks>
grab_super_passive(sb)
down_read_trylock(sb->s_umount)
<fails>
<shrinker aborts>
....
<shrinkers finish running>
up_read(shrinker_rwsem)
<unblocks>
<removes shrinker>
up_write(shrinker_rwsem)
->kill_sb()
....
So it is safe to deregister the shrinker before ->kill_sb().
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dave Chinner <david@fromorbit.com>
Tested-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Cc: Bob Liu <bob.liu@oracle.com>
Cc: Jan Kara <jack@suse.cz>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Kirill A. Shutemov [Wed, 4 Jun 2014 23:10:45 +0000 (16:10 -0700)]
mm: fix typo in comment in do_fault_around()
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Matthew Wilcox [Wed, 4 Jun 2014 23:10:44 +0000 (16:10 -0700)]
mm/msync.c: sync only the requested range in msync()
msync() currently syncs more than POSIX requires or BSD or Solaris
implement. It is supposed to be equivalent to fdatasync(), not fsync(),
and it is only supposed to sync the portion of the file that overlaps the
range passed to msync.
If the VMA is non-linear, fall back to syncing the entire file, but we
still optimise to only fdatasync() the entire file, not the full fsync().
akpm: there are obvious concerns with bck-compatibility: is anyone relying
on the undocumented side-effect for their data integrity? And how would
they ever know if this change broke their data integrity?
We think the risk is reasonably low, and this patch brings the kernel into
line with other OS's and with what the manpage has always said...
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Cc: Chris Mason <clm@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Chen Yucong [Wed, 4 Jun 2014 23:10:43 +0000 (16:10 -0700)]
hwpoison: remove unused global variable in do_machine_check()
Remove an unused global variable mce_entry and relative operations in
do_machine_check().
Signed-off-by: Chen Yucong <slaoub@gmail.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Vlastimil Babka [Wed, 4 Jun 2014 23:10:41 +0000 (16:10 -0700)]
mm, compaction: properly signal and act upon lock and need_sched() contention
Compaction uses compact_checklock_irqsave() function to periodically check
for lock contention and need_resched() to either abort async compaction,
or to free the lock, schedule and retake the lock. When aborting,
cc->contended is set to signal the contended state to the caller. Two
problems have been identified in this mechanism.
First, compaction also calls directly cond_resched() in both scanners when
no lock is yet taken. This call either does not abort async compaction,
or set cc->contended appropriately. This patch introduces a new
compact_should_abort() function to achieve both. In isolate_freepages(),
the check frequency is reduced to once by SWAP_CLUSTER_MAX pageblocks to
match what the migration scanner does in the preliminary page checks. In
case a pageblock is found suitable for calling isolate_freepages_block(),
the checks within there are done on higher frequency.
Second, isolate_freepages() does not check if isolate_freepages_block()
aborted due to contention, and advances to the next pageblock. This
violates the principle of aborting on contention, and might result in
pageblocks not being scanned completely, since the scanning cursor is
advanced. This problem has been noticed in the code by Joonsoo Kim when
reviewing related patches. This patch makes isolate_freepages_block()
check the cc->contended flag and abort.
In case isolate_freepages() has already isolated some pages before
aborting due to contention, page migration will proceed, which is OK since
we do not want to waste the work that has been done, and page migration
has own checks for contention. However, we do not want another isolation
attempt by either of the scanners, so cc->contended flag check is added
also to compaction_alloc() and compact_finished() to make sure compaction
is aborted right after the migration.
The outcome of the patch should be reduced lock contention by async
compaction and lower latencies for higher-order allocations where direct
compaction is involved.
[akpm@linux-foundation.org: fix typo in comment]
Reported-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Rik van Riel <riel@redhat.com>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Tested-by: Kevin Hilman <khilman@linaro.org>
Tested-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Fabio Estevam <fabio.estevam@freescale.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fabian Frederick [Wed, 4 Jun 2014 23:10:40 +0000 (16:10 -0700)]
fs/hugetlbfs/inode.c: remove null test before kfree
Fix checkpatch warning:
WARNING: kfree(NULL) is safe this check is probably not required
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fabian Frederick [Wed, 4 Jun 2014 23:10:39 +0000 (16:10 -0700)]
fs/hugetlbfs/inode.c: use static const for dentry_operations
...like other filesystems.
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fabian Frederick [Wed, 4 Jun 2014 23:10:39 +0000 (16:10 -0700)]
fs/hugetlbfs/inode.c: add static to hugetlbfs_i_mmap_mutex_key
hugetlbfs_i_mmap_mutex_key is only used in inode.c
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jianyu Zhan [Wed, 4 Jun 2014 23:10:38 +0000 (16:10 -0700)]
mm/vmscan.c: use DIV_ROUND_UP for calculation of zone's balance_gap and correct comments.
Currently, we use (zone->managed_pages + KSWAPD_ZONE_BALANCE_GAP_RATIO-1)
/ KSWAPD_ZONE_BALANCE_GAP_RATIO to avoid a zero gap value. It's better to
use DIV_ROUND_UP macro for neater code and clear meaning.
Besides, the gap value is calculated against the per-zone "managed pages",
not "present pages". This patch also corrects the comment and do some
rephrasing.
Signed-off-by: Jianyu Zhan <nasa4836@gmail.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Rafael Aquini <aquini@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andy Shevchenko [Wed, 4 Jun 2014 23:10:37 +0000 (16:10 -0700)]
include/linux/gfp.h: exclude duplicate header
mmdebug.h is included twice.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jianyu Zhan [Wed, 4 Jun 2014 23:10:36 +0000 (16:10 -0700)]
mm, hugetlb: move the error handle logic out of normal code path
alloc_huge_page() now mixes normal code path with error handle logic.
This patches move out the error handle logic, to make normal code path
more clean and redue code duplicate.
Signed-off-by: Jianyu Zhan <nasa4836@gmail.com>
Acked-by: Davidlohr Bueso <davidlohr@hp.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Naoya Horiguchi [Wed, 4 Jun 2014 23:10:35 +0000 (16:10 -0700)]
mm/memory-failure.c: move comment
The comment about pages under writeback is far from the relevant code, so
let's move it to the right place.
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mel Gorman [Wed, 4 Jun 2014 23:10:34 +0000 (16:10 -0700)]
mm: avoid unnecessary atomic operations during end_page_writeback()
If a page is marked for immediate reclaim then it is moved to the tail of
the LRU list. This occurs when the system is under enough memory pressure
for pages under writeback to reach the end of the LRU but we test for this
using atomic operations on every writeback. This patch uses an optimistic
non-atomic test first. It'll miss some pages in rare cases but the
consequences are not severe enough to warrant such a penalty.
While the function does not dominate profiles during a simple dd test the
cost of it is reduced.
73048 0.7428 vmlinux-3.15.0-rc5-mmotm-
20140513 end_page_writeback
23740 0.2409 vmlinux-3.15.0-rc5-lessatomic end_page_writeback
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mel Gorman [Wed, 4 Jun 2014 23:10:33 +0000 (16:10 -0700)]
mm: page_alloc: calculate classzone_idx once from the zonelist ref
There is no need to calculate zone_idx(preferred_zone) multiple times
or use the pgdat to figure it out.
Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Jan Kara <jack@suse.cz>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mel Gorman [Wed, 4 Jun 2014 23:10:31 +0000 (16:10 -0700)]
mm: non-atomically mark page accessed during page cache allocation where possible
aops->write_begin may allocate a new page and make it visible only to have
mark_page_accessed called almost immediately after. Once the page is
visible the atomic operations are necessary which is noticable overhead
when writing to an in-memory filesystem like tmpfs but should also be
noticable with fast storage. The objective of the patch is to initialse
the accessed information with non-atomic operations before the page is
visible.
The bulk of filesystems directly or indirectly use
grab_cache_page_write_begin or find_or_create_page for the initial
allocation of a page cache page. This patch adds an init_page_accessed()
helper which behaves like the first call to mark_page_accessed() but may
called before the page is visible and can be done non-atomically.
The primary APIs of concern in this care are the following and are used
by most filesystems.
find_get_page
find_lock_page
find_or_create_page
grab_cache_page_nowait
grab_cache_page_write_begin
All of them are very similar in detail to the patch creates a core helper
pagecache_get_page() which takes a flags parameter that affects its
behavior such as whether the page should be marked accessed or not. Then
old API is preserved but is basically a thin wrapper around this core
function.
Each of the filesystems are then updated to avoid calling
mark_page_accessed when it is known that the VM interfaces have already
done the job. There is a slight snag in that the timing of the
mark_page_accessed() has now changed so in rare cases it's possible a page
gets to the end of the LRU as PageReferenced where as previously it might
have been repromoted. This is expected to be rare but it's worth the
filesystem people thinking about it in case they see a problem with the
timing change. It is also the case that some filesystems may be marking
pages accessed that previously did not but it makes sense that filesystems
have consistent behaviour in this regard.
The test case used to evaulate this is a simple dd of a large file done
multiple times with the file deleted on each iterations. The size of the
file is 1/10th physical memory to avoid dirty page balancing. In the
async case it will be possible that the workload completes without even
hitting the disk and will have variable results but highlight the impact
of mark_page_accessed for async IO. The sync results are expected to be
more stable. The exception is tmpfs where the normal case is for the "IO"
to not hit the disk.
The test machine was single socket and UMA to avoid any scheduling or NUMA
artifacts. Throughput and wall times are presented for sync IO, only wall
times are shown for async as the granularity reported by dd and the
variability is unsuitable for comparison. As async results were variable
do to writback timings, I'm only reporting the maximum figures. The sync
results were stable enough to make the mean and stddev uninteresting.
The performance results are reported based on a run with no profiling.
Profile data is based on a separate run with oprofile running.
async dd
3.15.0-rc3 3.15.0-rc3
vanilla accessed-v2
ext3 Max elapsed 13.9900 ( 0.00%) 11.5900 ( 17.16%)
tmpfs Max elapsed 0.5100 ( 0.00%) 0.4900 ( 3.92%)
btrfs Max elapsed 12.8100 ( 0.00%) 12.7800 ( 0.23%)
ext4 Max elapsed 18.6000 ( 0.00%) 13.3400 ( 28.28%)
xfs Max elapsed 12.5600 ( 0.00%) 2.0900 ( 83.36%)
The XFS figure is a bit strange as it managed to avoid a worst case by
sheer luck but the average figures looked reasonable.
samples percentage
ext3 86107 0.9783 vmlinux-3.15.0-rc4-vanilla mark_page_accessed
ext3 23833 0.2710 vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed
ext3 5036 0.0573 vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed
ext4 64566 0.8961 vmlinux-3.15.0-rc4-vanilla mark_page_accessed
ext4 5322 0.0713 vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed
ext4 2869 0.0384 vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed
xfs 62126 1.7675 vmlinux-3.15.0-rc4-vanilla mark_page_accessed
xfs 1904 0.0554 vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed
xfs 103 0.0030 vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed
btrfs 10655 0.1338 vmlinux-3.15.0-rc4-vanilla mark_page_accessed
btrfs 2020 0.0273 vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed
btrfs 587 0.0079 vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed
tmpfs 59562 3.2628 vmlinux-3.15.0-rc4-vanilla mark_page_accessed
tmpfs 1210 0.0696 vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed
tmpfs 94 0.0054 vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed
[akpm@linux-foundation.org: don't run init_page_accessed() against an uninitialised pointer]
Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Jan Kara <jack@suse.cz>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Tested-by: Prabhakar Lad <prabhakar.csengg@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>