[tip: sched/core] sched/fair: Reduce the window for duplicated update

2021-03-06 Thread tip-bot2 for Vincent Guittot 
The following commit has been merged into the sched/core branch of tip:

Commit-ID: 39b6a429c30482c349f1bb3746470fe473cbdb0f
Gitweb:
https://git.kernel.org/tip/39b6a429c30482c349f1bb3746470fe473cbdb0f
Author:Vincent Guittot 
AuthorDate:Wed, 24 Feb 2021 14:30:07 +01:00
Committer: Ingo Molnar 
CommitterDate: Sat, 06 Mar 2021 12:40:22 +01:00

sched/fair: Reduce the window for duplicated update

Start to update last_blocked_load_update_tick to reduce the possibility
of another cpu starting the update one more time

Signed-off-by: Vincent Guittot 
Signed-off-by: Peter Zijlstra (Intel) 
Signed-off-by: Ingo Molnar 
Reviewed-by: Valentin Schneider 
Link: 
https://lkml.kernel.org/r/20210224133007.28644-8-vincent.guit...@linaro.org
---
 kernel/sched/fair.c | 11 ---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index e87e1b3..f1b55f9 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -7852,16 +7852,20 @@ static inline bool others_have_blocked(struct rq *rq)
return false;
 }
 
-static inline void update_blocked_load_status(struct rq *rq, bool has_blocked)
+static inline void update_blocked_load_tick(struct rq *rq)
 {
-   rq->last_blocked_load_update_tick = jiffies;
+   WRITE_ONCE(rq->last_blocked_load_update_tick, jiffies);
+}
 
+static inline void update_blocked_load_status(struct rq *rq, bool has_blocked)
+{
if (!has_blocked)
rq->has_blocked_load = 0;
 }
 #else
 static inline bool cfs_rq_has_blocked(struct cfs_rq *cfs_rq) { return false; }
 static inline bool others_have_blocked(struct rq *rq) { return false; }
+static inline void update_blocked_load_tick(struct rq *rq) {}
 static inline void update_blocked_load_status(struct rq *rq, bool has_blocked) 
{}
 #endif
 
@@ -8022,6 +8026,7 @@ static void update_blocked_averages(int cpu)
struct rq_flags rf;
 
rq_lock_irqsave(rq, );
+   update_blocked_load_tick(rq);
update_rq_clock(rq);
 
decayed |= __update_blocked_others(rq, );
@@ -8363,7 +8368,7 @@ static bool update_nohz_stats(struct rq *rq)
if (!cpumask_test_cpu(cpu, nohz.idle_cpus_mask))
return false;
 
-   if (!time_after(jiffies, rq->last_blocked_load_update_tick))
+   if (!time_after(jiffies, READ_ONCE(rq->last_blocked_load_update_tick)))
return true;
 
update_blocked_averages(cpu);

[tip: sched/core] sched/fair: Reduce the window for duplicated update

2021-03-03 Thread tip-bot2 for Vincent Guittot 
The following commit has been merged into the sched/core branch of tip:

Commit-ID: 780eec5b50930b34e2f096b4dce5368d90497b55
Gitweb:
https://git.kernel.org/tip/780eec5b50930b34e2f096b4dce5368d90497b55
Author:Vincent Guittot 
AuthorDate:Wed, 24 Feb 2021 14:30:07 +01:00
Committer: Peter Zijlstra 
CommitterDate: Wed, 03 Mar 2021 10:32:59 +01:00

sched/fair: Reduce the window for duplicated update

Start to update last_blocked_load_update_tick to reduce the possibility
of another cpu starting the update one more time

Signed-off-by: Vincent Guittot 
Signed-off-by: Peter Zijlstra (Intel) 
Reviewed-by: Valentin Schneider 
Link: 
https://lkml.kernel.org/r/20210224133007.28644-8-vincent.guit...@linaro.org
---
 kernel/sched/fair.c | 11 ---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index e87e1b3..f1b55f9 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -7852,16 +7852,20 @@ static inline bool others_have_blocked(struct rq *rq)
return false;
 }
 
-static inline void update_blocked_load_status(struct rq *rq, bool has_blocked)
+static inline void update_blocked_load_tick(struct rq *rq)
 {
-   rq->last_blocked_load_update_tick = jiffies;
+   WRITE_ONCE(rq->last_blocked_load_update_tick, jiffies);
+}
 
+static inline void update_blocked_load_status(struct rq *rq, bool has_blocked)
+{
if (!has_blocked)
rq->has_blocked_load = 0;
 }
 #else
 static inline bool cfs_rq_has_blocked(struct cfs_rq *cfs_rq) { return false; }
 static inline bool others_have_blocked(struct rq *rq) { return false; }
+static inline void update_blocked_load_tick(struct rq *rq) {}
 static inline void update_blocked_load_status(struct rq *rq, bool has_blocked) 
{}
 #endif
 
@@ -8022,6 +8026,7 @@ static void update_blocked_averages(int cpu)
struct rq_flags rf;
 
rq_lock_irqsave(rq, );
+   update_blocked_load_tick(rq);
update_rq_clock(rq);
 
decayed |= __update_blocked_others(rq, );
@@ -8363,7 +8368,7 @@ static bool update_nohz_stats(struct rq *rq)
if (!cpumask_test_cpu(cpu, nohz.idle_cpus_mask))
return false;
 
-   if (!time_after(jiffies, rq->last_blocked_load_update_tick))
+   if (!time_after(jiffies, READ_ONCE(rq->last_blocked_load_update_tick)))
return true;
 
update_blocked_averages(cpu);

[tip: sched/core] sched/fair: Reduce the window for duplicated update

2021-03-02 Thread tip-bot2 for Vincent Guittot 
The following commit has been merged into the sched/core branch of tip:

Commit-ID: 839ffb99d94f930fecbdee2fdfb883b10c30326b
Gitweb:
https://git.kernel.org/tip/839ffb99d94f930fecbdee2fdfb883b10c30326b
Author:Vincent Guittot 
AuthorDate:Wed, 24 Feb 2021 14:30:07 +01:00
Committer: Peter Zijlstra 
CommitterDate: Mon, 01 Mar 2021 18:17:25 +01:00

sched/fair: Reduce the window for duplicated update

Start to update last_blocked_load_update_tick to reduce the possibility
of another cpu starting the update one more time

Signed-off-by: Vincent Guittot 
Signed-off-by: Peter Zijlstra (Intel) 
Reviewed-by: Valentin Schneider 
Link: 
https://lkml.kernel.org/r/20210224133007.28644-8-vincent.guit...@linaro.org
---
 kernel/sched/fair.c | 11 ---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index e87e1b3..f1b55f9 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -7852,16 +7852,20 @@ static inline bool others_have_blocked(struct rq *rq)
return false;
 }
 
-static inline void update_blocked_load_status(struct rq *rq, bool has_blocked)
+static inline void update_blocked_load_tick(struct rq *rq)
 {
-   rq->last_blocked_load_update_tick = jiffies;
+   WRITE_ONCE(rq->last_blocked_load_update_tick, jiffies);
+}
 
+static inline void update_blocked_load_status(struct rq *rq, bool has_blocked)
+{
if (!has_blocked)
rq->has_blocked_load = 0;
 }
 #else
 static inline bool cfs_rq_has_blocked(struct cfs_rq *cfs_rq) { return false; }
 static inline bool others_have_blocked(struct rq *rq) { return false; }
+static inline void update_blocked_load_tick(struct rq *rq) {}
 static inline void update_blocked_load_status(struct rq *rq, bool has_blocked) 
{}
 #endif
 
@@ -8022,6 +8026,7 @@ static void update_blocked_averages(int cpu)
struct rq_flags rf;
 
rq_lock_irqsave(rq, );
+   update_blocked_load_tick(rq);
update_rq_clock(rq);
 
decayed |= __update_blocked_others(rq, );
@@ -8363,7 +8368,7 @@ static bool update_nohz_stats(struct rq *rq)
if (!cpumask_test_cpu(cpu, nohz.idle_cpus_mask))
return false;
 
-   if (!time_after(jiffies, rq->last_blocked_load_update_tick))
+   if (!time_after(jiffies, READ_ONCE(rq->last_blocked_load_update_tick)))
return true;
 
update_blocked_averages(cpu);