From: SeongJae Park <sj@xxxxxxxxxx> Subject: mm/damon/core: use better timer mechanisms selection threshold Patch series "mm/damon: Trivial fixups and improvements". This patchset contains trivial fixups and improvements for DAMON and its kunit/kselftest tests. This patch (of 11): DAMON is using hrtimer if requested sleep time is <=100ms, while the suggested threshold[1] is <=20ms. This commit applies the threshold. [1] Documentation/timers/timers-howto.rst Link: https://lkml.kernel.org/r/20211201150440.1088-2-sj@xxxxxxxxxx Fixes: ee801b7dd7822 ("mm/damon/schemes: activate schemes based on a watermarks mechanism") Signed-off-by: SeongJae Park <sj@xxxxxxxxxx> Cc: Shuah Khan <shuah@xxxxxxxxxx> Cc: Brendan Higgins <brendanhiggins@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/damon/core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/mm/damon/core.c~mm-damon-core-use-better-timer-mechanisms-selection-threshold +++ a/mm/damon/core.c @@ -980,7 +980,8 @@ static unsigned long damos_wmark_wait_us static void kdamond_usleep(unsigned long usecs) { - if (usecs > 100 * 1000) + /* See Documentation/timers/timers-howto.rst for the thresholds */ + if (usecs > 20 * USEC_PER_MSEC) schedule_timeout_idle(usecs_to_jiffies(usecs)); else usleep_idle_range(usecs, usecs + 1); _
