lkml.org 
[lkml]   [2018]   [Jul]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] sched/fair: sync expires_seq in distribute_cfs_runtime()
Date
Each time we sync cfs_rq->runtime_expires with cfs_b->runtime_expires,
we should sync its ->expires_seq too. However it is missing
for distribute_cfs_runtime(), especially the slack timer call path.

Fixes: 512ac999d275 ("sched/fair: Fix bandwidth timer clock drift condition")
Cc: Xunlei Pang <xlpang@linux.alibaba.com>
Cc: Ben Segall <bsegall@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
---
kernel/sched/fair.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 2f0a0be4d344..910c50db3d74 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -4857,7 +4857,7 @@ void unthrottle_cfs_rq(struct cfs_rq *cfs_rq)
}

static u64 distribute_cfs_runtime(struct cfs_bandwidth *cfs_b,
- u64 remaining, u64 expires)
+ u64 remaining, u64 expires, int expires_seq)
{
struct cfs_rq *cfs_rq;
u64 runtime;
@@ -4880,6 +4880,7 @@ static u64 distribute_cfs_runtime(struct cfs_bandwidth *cfs_b,

cfs_rq->runtime_remaining += runtime;
cfs_rq->runtime_expires = expires;
+ cfs_rq->expires_seq = expires_seq;

/* we check whether we're throttled above */
if (cfs_rq->runtime_remaining > 0)
@@ -4905,7 +4906,7 @@ static u64 distribute_cfs_runtime(struct cfs_bandwidth *cfs_b,
static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun)
{
u64 runtime, runtime_expires;
- int throttled;
+ int throttled, expires_seq;

/* no need to continue the timer with no bandwidth constraint */
if (cfs_b->quota == RUNTIME_INF)
@@ -4933,6 +4934,7 @@ static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun)
cfs_b->nr_throttled += overrun;

runtime_expires = cfs_b->runtime_expires;
+ expires_seq = cfs_b->expires_seq;

/*
* This check is repeated as we are holding onto the new bandwidth while
@@ -4946,7 +4948,7 @@ static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun)
raw_spin_unlock(&cfs_b->lock);
/* we can't nest cfs_b->lock while distributing bandwidth */
runtime = distribute_cfs_runtime(cfs_b, runtime,
- runtime_expires);
+ runtime_expires, expires_seq);
raw_spin_lock(&cfs_b->lock);

throttled = !list_empty(&cfs_b->throttled_cfs_rq);
@@ -5055,6 +5057,7 @@ static __always_inline void return_cfs_rq_runtime(struct cfs_rq *cfs_rq)
static void do_sched_cfs_slack_timer(struct cfs_bandwidth *cfs_b)
{
u64 runtime = 0, slice = sched_cfs_bandwidth_slice();
+ int expires_seq;
u64 expires;

/* confirm we're still not at a refresh boundary */
@@ -5068,12 +5071,13 @@ static void do_sched_cfs_slack_timer(struct cfs_bandwidth *cfs_b)
runtime = cfs_b->runtime;

expires = cfs_b->runtime_expires;
+ expires_seq = cfs_b->expires_seq;
raw_spin_unlock(&cfs_b->lock);

if (!runtime)
return;

- runtime = distribute_cfs_runtime(cfs_b, runtime, expires);
+ runtime = distribute_cfs_runtime(cfs_b, runtime, expires, expires_seq);

raw_spin_lock(&cfs_b->lock);
if (expires == cfs_b->runtime_expires)
--
2.14.4
\
 
 \ /
  Last update: 2018-07-28 02:25    [W:0.055 / U:1.588 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site