From: SeongJae Park sj@kernel.org
mainline inclusion from mainline-v5.16-rc5 commit 70e9274805fccfd175d0431a947bfd11ee7df40e category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I4RTX9
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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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 oleksandr@natalenko.name Signed-off-by: SeongJae Park sj@kernel.org Tested-by: Oleksandr 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: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org (cherry picked from commit 70e9274805fccfd175d0431a947bfd11ee7df40e) Signed-off-by: Yue Zou zouyue3@huawei.com Reviewed-by: Kefeng Wangwangkefeng.wang@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- 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);