From: Wen Yang Date: Tue, 25 Apr 2023 15:52:35 +0000 (+0800) Subject: mm: compaction: optimize compact_memory to comply with the admin-guide X-Git-Tag: v6.5-rc1~176^2~374 X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=8b9167cd9ef039d95b65ef9600a7507795173121;p=tomoyo%2Ftomoyo-test1.git mm: compaction: optimize compact_memory to comply with the admin-guide For the /proc/sys/vm/compact_memory file, the admin-guide states: When 1 is written to the file, all zones are compacted such that free memory is available in contiguous blocks where possible. This can be important for example in the allocation of huge pages although processes will also directly compact memory as required But it was not strictly followed, writing any value would cause all zones to be compacted. It has been slightly optimized to comply with the admin-guide. Enforce the 1 on the unlikely chance that the sysctl handler is ever extended to do something different. Commit ef4984384172 ("mm/compaction: remove unused variable sysctl_compact_memory") has also been optimized a bit here, as the declaration in the external header file has been eliminated, and sysctl_compact_memory also needs to be verified. [akpm@linux-foundation.org: add __read_mostly, per Mel] Link: https://lkml.kernel.org/r/tencent_DFF54DB2A60F3333F97D3F6B5441519B050A@qq.com Signed-off-by: Wen Yang Acked-by: Mel Gorman Cc: Oscar Salvador Cc: William Lam Cc: Pintu Kumar Cc: Fu Wei Signed-off-by: Andrew Morton --- diff --git a/mm/compaction.c b/mm/compaction.c index c8bcdea15f5f..5584fa5fa3d4 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -1736,6 +1736,7 @@ static int sysctl_compact_unevictable_allowed __read_mostly = CONFIG_COMPACT_UNE */ static unsigned int __read_mostly sysctl_compaction_proactiveness = 20; static int sysctl_extfrag_threshold = 500; +static int __read_mostly sysctl_compact_memory; static inline void update_fast_start_pfn(struct compact_control *cc, unsigned long pfn) @@ -2780,6 +2781,15 @@ static int compaction_proactiveness_sysctl_handler(struct ctl_table *table, int static int sysctl_compaction_handler(struct ctl_table *table, int write, void *buffer, size_t *length, loff_t *ppos) { + int ret; + + ret = proc_dointvec(table, write, buffer, length, ppos); + if (ret) + return ret; + + if (sysctl_compact_memory != 1) + return -EINVAL; + if (write) compact_nodes(); @@ -3095,7 +3105,7 @@ static int proc_dointvec_minmax_warn_RT_change(struct ctl_table *table, static struct ctl_table vm_compaction[] = { { .procname = "compact_memory", - .data = NULL, + .data = &sysctl_compact_memory, .maxlen = sizeof(int), .mode = 0200, .proc_handler = sysctl_compaction_handler,