cputime: Remove irqsave from seqlock readers
authorThomas Gleixner <tglx@linutronix.de>
Fri, 15 Feb 2013 22:47:07 +0000 (23:47 +0100)
committerIngo Molnar <mingo@kernel.org>
Tue, 19 Feb 2013 07:05:53 +0000 (08:05 +0100)
The reader side code has no requirement to disable interrupts while
sampling data. The sequence counter is enough to ensure consistency.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
kernel/sched/cputime.c

index ccff2752725ad51bfe6bcfd3425eb0e0a516a7bb..9857329ed2804a6b3255bd402a73722b8ae33ecc 100644 (file)
@@ -729,18 +729,17 @@ void vtime_init_idle(struct task_struct *t)
 
 cputime_t task_gtime(struct task_struct *t)
 {
-       unsigned long flags;
        unsigned int seq;
        cputime_t gtime;
 
        do {
-               seq = read_seqbegin_irqsave(&t->vtime_seqlock, flags);
+               seq = read_seqbegin(&t->vtime_seqlock);
 
                gtime = t->gtime;
                if (t->flags & PF_VCPU)
                        gtime += vtime_delta(t);
 
-       } while (read_seqretry_irqrestore(&t->vtime_seqlock, seq, flags));
+       } while (read_seqretry(&t->vtime_seqlock, seq));
 
        return gtime;
 }
@@ -756,7 +755,6 @@ fetch_task_cputime(struct task_struct *t,
                   cputime_t *u_src, cputime_t *s_src,
                   cputime_t *udelta, cputime_t *sdelta)
 {
-       unsigned long flags;
        unsigned int seq;
        unsigned long long delta;
 
@@ -764,7 +762,7 @@ fetch_task_cputime(struct task_struct *t,
                *udelta = 0;
                *sdelta = 0;
 
-               seq = read_seqbegin_irqsave(&t->vtime_seqlock, flags);
+               seq = read_seqbegin(&t->vtime_seqlock);
 
                if (u_dst)
                        *u_dst = *u_src;
@@ -788,7 +786,7 @@ fetch_task_cputime(struct task_struct *t,
                        if (t->vtime_snap_whence == VTIME_SYS)
                                *sdelta = delta;
                }
-       } while (read_seqretry_irqrestore(&t->vtime_seqlock, seq, flags));
+       } while (read_seqretry(&t->vtime_seqlock, seq));
 }