mm/memcg: move penalty delay clamping out of calculate_high_delay() (ff144e69) · Commits · 戴 / test

We will want to call calculate_high_delay() twice - once for memory and once for swap, and we should apply the clamp value to sum of the penalties. Clamping has to be applied outside of calculate_high_delay(). Signed-off-by:

Jakub Kicinski <kuba@kernel.org> Signed-off-by:

Andrew Morton <akpm@linux-foundation.org> Reviewed-by:

Shakeel Butt <shakeelb@google.com> Acked-by:

Johannes Weiner <hannes@cmpxchg.org> Cc: Chris Down <chris@chrisdown.name> Cc: Hugh Dickins <hughd@google.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Tejun Heo <tj@kernel.org> Link: http://lkml.kernel.org/r/20200527195846.102707-3-kuba@kernel.org Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

mm/memcontrol.c

+8 −8

Original line number	Diff line number	Diff line
		@@ -2386,14 +2386,7 @@ static unsigned long calculate_high_delay(struct mem_cgroup *memcg,
		* MEMCG_CHARGE_BATCH pages is nominal, so work out how much smaller or
		* larger the current charge patch is than that.
		*/
		penalty_jiffies = penalty_jiffies * nr_pages / MEMCG_CHARGE_BATCH;

		/*
		* Clamp the max delay per usermode return so as to still keep the
		* application moving forwards and also permit diagnostics, albeit
		* extremely slowly.
		*/
		return min(penalty_jiffies, MEMCG_MAX_HIGH_DELAY_JIFFIES);
		return penalty_jiffies * nr_pages / MEMCG_CHARGE_BATCH;
		}

		/*
		@@ -2421,6 +2414,13 @@ void mem_cgroup_handle_over_high(void)
		penalty_jiffies = calculate_high_delay(memcg, nr_pages,
		mem_find_max_overage(memcg));

		/*
		* Clamp the max delay per usermode return so as to still keep the
		* application moving forwards and also permit diagnostics, albeit
		* extremely slowly.
		*/
		penalty_jiffies = min(penalty_jiffies, MEMCG_MAX_HIGH_DELAY_JIFFIES);

		/*
		* Don't sleep if the amount of jiffies this memcg owes us is so low
		* that it's not even worth doing, in an attempt to be nice to those who

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