cputime: Remove irqsave from seqlock readers

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>

1 files changed, 4 insertions, 6 deletions

diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c
index ccff2752725a..9857329ed280 100644
--- a/kernel/sched/cputime.c
+++ b/kernel/sched/cputime.c
@@ -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));
 }