The patch titled
Subject: mm/damon/core: fix fake load reports due to uninterruptible sleeps
has been added to the -mm tree. Its filename is
mm-damon-core-fix-fake-load-reports-due-to-uninterruptible-sleeps.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-damon-core-fix-fake-load-reports-due-to-uninterruptible-sleeps.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-damon-core-fix-fake-load-reports-due-to-uninterruptible-sleeps.patch
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------------------------------------------------------
From: SeongJae Park <sj@xxxxxxxxxx>
Subject: 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@xxxxxxxxxxxxxx/
Link: https://lkml.kernel.org/r/20211126145015.15862-3-sj@xxxxxxxxxx
Fixes: 2224d8485492 ("mm: introduce Data Access MONitor (DAMON)")
Reported-by: Oleksandr Natalenko <oleksandr@xxxxxxxxxxxxxx>
Signed-off-by: SeongJae Park <sj@xxxxxxxxxx>
Cc: Oleksandr Natalenko <oleksandr@xxxxxxxxxxxxxx>
Cc: John Stultz <john.stultz@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/damon/core.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
--- a/mm/damon/core.c~mm-damon-core-fix-fake-load-reports-due-to-uninterruptible-sleeps
+++ a/mm/damon/core.c
@@ -981,9 +981,9 @@ static unsigned long damos_wmark_wait_us
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);
_
Patches currently in -mm which might be from sj@xxxxxxxxxx are
timers-implement-usleep_idle_range.patch
mm-damon-core-fix-fake-load-reports-due-to-uninterruptible-sleeps.patch
mm-damon-remove-some-no-need-func-definitions-in-damonh-file-fix.patch
