Re: [PATCH mm-hotfixes-unstable 1/3] mm/damon/core: reset watermark wait state on each iteration

[sashiko-bot@kernel.org]

> From: Aveline Noir <jm5905938@gmail.com>
> 
> Found while reviewing the DAMON source code that if an online commit
> removes all schemes while kdamond is waiting for watermark activation,
> the scheme loop becomes empty but min_wait_time keeps the previous
> positive value.  kdamond then keeps sleeping instead of resuming
> monitoring without schemes.
> 
> The way to wake up the kdamond again without DAMON is bit complicated.
> Install a scheme having watermarks that can activate the kdamond again,
> and remove the scheme again.  Doable but cumbersome and complicated.
> 
> Initialize min_wait_time and init_wait_time on each loop iteration so
> the wait is calculated from the current schemes and an empty scheme
> list resumes monitoring.
> 
> Fixes: da87878010e5 ("mm/damon/sysfs: support online inputs update")
> Cc: <stable@vger.kernel.org> # 5.19.x
> Assisted-by: LLM
> Signed-off-by: Aveline Noir <jm5905938@gmail.com>
> Reviewed-by: SJ Park <sj@kernel.org>
> Signed-off-by: SJ Park <sj@kernel.org>

Sashiko has reviewed this patch and found no issues.

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