Messages in this thread Patch in this message | | | Date | Fri, 30 Sep 2016 04:55:57 -0700 | From | tip-bot for Dietmar Eggemann <> | Subject | [tip:sched/core] sched/fair: Fix fixed point arithmetic width for shares and effective load |
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Commit-ID: ab522e33f91799661aad47bebb691f241a9f6bb8 Gitweb: http://git.kernel.org/tip/ab522e33f91799661aad47bebb691f241a9f6bb8 Author: Dietmar Eggemann <dietmar.eggemann@arm.com> AuthorDate: Mon, 22 Aug 2016 15:00:41 +0100 Committer: Ingo Molnar <mingo@kernel.org> CommitDate: Fri, 30 Sep 2016 10:53:19 +0200
sched/fair: Fix fixed point arithmetic width for shares and effective load
Since commit:
2159197d6677 ("sched/core: Enable increased load resolution on 64-bit kernels")
we now have two different fixed point units for load:
- 'shares' in calc_cfs_shares() has 20 bit fixed point unit on 64-bit kernels. Therefore use scale_load() on MIN_SHARES.
- 'wl' in effective_load() has 10 bit fixed point unit. Therefore use scale_load_down() on tg->shares which has 20 bit fixed point unit on 64-bit kernels.
Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1471874441-24701-1-git-send-email-dietmar.eggemann@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org> --- kernel/sched/fair.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 8fb4d19..786ef94 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -5017,9 +5017,9 @@ static long effective_load(struct task_group *tg, int cpu, long wl, long wg) * wl = S * s'_i; see (2) */ if (W > 0 && w < W) - wl = (w * (long)tg->shares) / W; + wl = (w * (long)scale_load_down(tg->shares)) / W; else - wl = tg->shares; + wl = scale_load_down(tg->shares); /* * Per the above, wl is the new se->load.weight value; since
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