From 70e9274805fccfd175d0431a947bfd11ee7df40e Mon Sep 17 00:00:00 2001 From: SeongJae Park Date: Fri, 10 Dec 2021 14:46:25 -0800 Subject: [PATCH] mm/damon/core: fix fake load reports due to uninterruptible sleeps Because DAMON sleeps in uninterruptible mode, /proc/loadavg reports fake load while DAMON is turned on, though it is doing nothing. This can confuse users[1]. To avoid the case, this commit makes DAMON sleeps in idle mode. [1] https://lore.kernel.org/all/11868371.O9o76ZdvQC@natalenko.name/ Link: https://lkml.kernel.org/r/20211126145015.15862-3-sj@kernel.org Fixes: 2224d8485492 ("mm: introduce Data Access MONitor (DAMON)") Reported-by: Oleksandr Natalenko Signed-off-by: SeongJae Park Tested-by: Oleksandr Natalenko Cc: John Stultz Cc: Thomas Gleixner Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/damon/core.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/mm/damon/core.c b/mm/damon/core.c index c381b3c525d0..2daffd5820fe 100644 --- a/mm/damon/core.c +++ b/mm/damon/core.c @@ -981,9 +981,9 @@ static unsigned long damos_wmark_wait_us(struct damos *scheme) static void kdamond_usleep(unsigned long usecs) { if (usecs > 100 * 1000) - schedule_timeout_interruptible(usecs_to_jiffies(usecs)); + schedule_timeout_idle(usecs_to_jiffies(usecs)); else - usleep_range(usecs, usecs + 1); + usleep_idle_range(usecs, usecs + 1); } /* Returns negative error code if it's not activated but should return */ @@ -1038,7 +1038,7 @@ static int kdamond_fn(void *data) ctx->callback.after_sampling(ctx)) done = true; - usleep_range(ctx->sample_interval, ctx->sample_interval + 1); + kdamond_usleep(ctx->sample_interval); if (ctx->primitive.check_accesses) max_nr_accesses = ctx->primitive.check_accesses(ctx); -- 2.11.0