From 7aa2c016db2162defff77f6f5731bff3f25e5175 Mon Sep 17 00:00:00 2001 From: Dongsheng Yang Date: Thu, 8 May 2014 18:33:49 +0900 Subject: [PATCH] sched: Consolidate open coded implementations of nice level frobbing into nice_to_rlimit() and rlimit_to_nice() Signed-off-by: Dongsheng Yang Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/a568a1e3cc8e78648f41b5035fa5e381d36274da.1399532322.git.yangds.fnst@cn.fujitsu.com Signed-off-by: Ingo Molnar --- drivers/staging/android/binder.c | 2 +- include/linux/sched/prio.h | 16 ++++++++++++++++ kernel/sched/core.c | 2 +- kernel/sys.c | 6 +++--- 4 files changed, 21 insertions(+), 5 deletions(-) diff --git a/drivers/staging/android/binder.c b/drivers/staging/android/binder.c index 179b21b66504..9311bb67ec35 100644 --- a/drivers/staging/android/binder.c +++ b/drivers/staging/android/binder.c @@ -436,7 +436,7 @@ static void binder_set_nice(long nice) set_user_nice(current, nice); return; } - min_nice = 20 - current->signal->rlim[RLIMIT_NICE].rlim_cur; + min_nice = rlimit_to_nice(current->signal->rlim[RLIMIT_NICE].rlim_cur); binder_debug(BINDER_DEBUG_PRIORITY_CAP, "%d: nice value %ld not allowed use %ld instead\n", current->pid, nice, min_nice); diff --git a/include/linux/sched/prio.h b/include/linux/sched/prio.h index ac322583c820..d9cf5a5762d9 100644 --- a/include/linux/sched/prio.h +++ b/include/linux/sched/prio.h @@ -41,4 +41,20 @@ #define TASK_USER_PRIO(p) USER_PRIO((p)->static_prio) #define MAX_USER_PRIO (USER_PRIO(MAX_PRIO)) +/* + * Convert nice value [19,-20] to rlimit style value [1,40]. + */ +static inline long nice_to_rlimit(long nice) +{ + return (MAX_NICE - nice + 1); +} + +/* + * Convert rlimit style value [1,40] to nice value [-20, 19]. + */ +static inline long rlimit_to_nice(long prio) +{ + return (MAX_NICE - prio + 1); +} + #endif /* _SCHED_PRIO_H */ diff --git a/kernel/sched/core.c b/kernel/sched/core.c index da302ca98f60..321d800e4baa 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -3033,7 +3033,7 @@ EXPORT_SYMBOL(set_user_nice); int can_nice(const struct task_struct *p, const int nice) { /* convert nice value [19,-20] to rlimit style value [1,40] */ - int nice_rlim = 20 - nice; + int nice_rlim = nice_to_rlimit(nice); return (nice_rlim <= task_rlimit(p, RLIMIT_NICE) || capable(CAP_SYS_NICE)); diff --git a/kernel/sys.c b/kernel/sys.c index fba0f29401ea..66a751ebf9d9 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -250,7 +250,7 @@ SYSCALL_DEFINE2(getpriority, int, which, int, who) else p = current; if (p) { - niceval = 20 - task_nice(p); + niceval = nice_to_rlimit(task_nice(p)); if (niceval > retval) retval = niceval; } @@ -261,7 +261,7 @@ SYSCALL_DEFINE2(getpriority, int, which, int, who) else pgrp = task_pgrp(current); do_each_pid_thread(pgrp, PIDTYPE_PGID, p) { - niceval = 20 - task_nice(p); + niceval = nice_to_rlimit(task_nice(p)); if (niceval > retval) retval = niceval; } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); @@ -277,7 +277,7 @@ SYSCALL_DEFINE2(getpriority, int, which, int, who) do_each_thread(g, p) { if (uid_eq(task_uid(p), uid)) { - niceval = 20 - task_nice(p); + niceval = nice_to_rlimit(task_nice(p)); if (niceval > retval) retval = niceval; } -- 2.11.0