Commit 70e92748 authored by SeongJae Park's avatar SeongJae Park Committed by Linus Torvalds

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: 2224d848 ("mm: introduce Data Access MONitor (DAMON)")
Reported-by: default avatarOleksandr Natalenko <oleksandr@natalenko.name>
Signed-off-by: default avatarSeongJae Park <sj@kernel.org>
Tested-by: default avatarOleksandr Natalenko <oleksandr@natalenko.name>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent e4779015
......@@ -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);
......
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