From: Stanislaw Gruszka <sgruszka@redhat.com>
To: linux-kernel@vger.kernel.org
Cc: Giovanni Gherdovich <ggherdovich@suse.cz>,
Linus Torvalds <torvalds@linux-foundation.org>,
Mel Gorman <mgorman@techsingularity.net>,
Mike Galbraith <mgalbraith@suse.de>,
Paolo Bonzini <pbonzini@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
Rik van Riel <riel@redhat.com>,
Thomas Gleixner <tglx@linutronix.de>,
Wanpeng Li <wanpeng.li@hotmail.com>,
Ingo Molnar <mingo@kernel.org>,
Stanislaw Gruszka <sgruszka@redhat.com>
Subject: [PATCH 2/3] sched/cputime: Make nr_migrations u32 on 32 bit cpus
Date: Thu, 1 Sep 2016 11:27:43 +0200 [thread overview]
Message-ID: <1472722064-7151-3-git-send-email-sgruszka@redhat.com> (raw)
In-Reply-To: <1472722064-7151-1-git-send-email-sgruszka@redhat.com>
My previous patch:
("sched/cputime: Improve scalability of times()/clock_gettime() on 32 bit cpus")
add new sum_exec_runtime_seqclock fields to sched_entity struct.
This changed the alignment of other fields of the sched_entity struct.
To preserve previous alignment, which makes variables commonly used
together are kept in a cache line, make nr_migrations field u32 on
32 bit architectures.
This field is used only for debugging and basically nr_migrations
should not be enormous number.
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
---
include/linux/sched.h | 5 +++--
kernel/sched/debug.c | 4 ++--
2 files changed, 5 insertions(+), 4 deletions(-)
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 65714bc..b9d9333 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1332,9 +1332,10 @@ struct sched_entity {
u64 vruntime;
u64 prev_sum_exec_runtime;
+#ifdef CONFIG_64BIT
u64 nr_migrations;
-
-#ifndef CONFIG_64BIT
+#else
+ u32 nr_migrations;
seqcount_t sum_exec_runtime_seqcount;
#endif
diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index 2a0a999..db85816 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -921,8 +921,8 @@ void proc_sched_show_task(struct task_struct *p, struct seq_file *m)
avg_per_cpu = p->se.sum_exec_runtime;
if (p->se.nr_migrations) {
- avg_per_cpu = div64_u64(avg_per_cpu,
- p->se.nr_migrations);
+ avg_per_cpu = div64_ul(avg_per_cpu,
+ p->se.nr_migrations);
} else {
avg_per_cpu = -1LL;
}
--
1.8.3.1
next prev parent reply other threads:[~2016-09-01 9:31 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-01 9:27 [PATCH 0/3] sched/cputime: sum_exec_runtime fixes for 32-bit cpus Stanislaw Gruszka
2016-09-01 9:27 ` [PATCH 1/3] sched/cputime: Improve scalability of times()/clock_gettime() on 32 bit cpus Stanislaw Gruszka
2016-09-01 9:49 ` Peter Zijlstra
2016-09-01 10:07 ` Stanislaw Gruszka
2016-09-01 10:29 ` Peter Zijlstra
2016-09-04 18:46 ` Giovanni Gherdovich
2016-09-01 9:55 ` kbuild test robot
2016-09-01 10:05 ` kbuild test robot
2016-09-01 11:18 ` kbuild test robot
2016-09-01 9:27 ` Stanislaw Gruszka [this message]
2016-09-01 9:27 ` [PATCH 3/3] sched/cputime: Protect other sum_exec_runtime reads " Stanislaw Gruszka
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