Commit 3b15f9d1 authored by Alex Rusuf's avatar Alex Rusuf Committed by Andrew Morton
Browse files

mm/damon/core: fix return value from damos_wmark_metric_value 

damos_wmark_metric_value's return value is 'unsigned long', so returning
-EINVAL as 'unsigned long' may turn out to be very different from the
expected one (using 2's complement) and treat as usual matric's value. 
So, fix that, checking if returned value is not 0.

Link: https://lkml.kernel.org/r/20240506180238.53842-1-sj@kernel.org


Fixes: ee801b7d ("mm/damon/schemes: activate schemes based on a watermarks mechanism")
Signed-off-by: default avatarAlex Rusuf <yorha.op@gmail.com>
Reviewed-by: default avatarSeongJae Park <sj@kernel.org>
Signed-off-by: default avatarSeongJae Park <sj@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 4f687281

mm/damon/core.c

+5 −4
Original line number Diff line number Diff line
@@ -1481,12 +1481,14 @@ static bool kdamond_need_stop(struct damon_ctx *ctx) 
	return true;

}



static unsigned long damos_wmark_metric_value(enum damos_wmark_metric metric)

static int damos_get_wmark_metric_value(enum damos_wmark_metric metric,

					unsigned long *metric_value)

{

	switch (metric) {

	case DAMOS_WMARK_FREE_MEM_RATE:

		return global_zone_page_state(NR_FREE_PAGES) * 1000 /

		*metric_value = global_zone_page_state(NR_FREE_PAGES) * 1000 /

		       totalram_pages();

		return 0;

	default:

		break;

	}
@@ -1501,10 +1503,9 @@ static unsigned long damos_wmark_wait_us(struct damos *scheme) 
{

	unsigned long metric;



	if (scheme->wmarks.metric == DAMOS_WMARK_NONE)

	if (damos_get_wmark_metric_value(scheme->wmarks.metric, &metric))

		return 0;



	metric = damos_wmark_metric_value(scheme->wmarks.metric);

	/* higher than high watermark or lower than low watermark */

	if (metric > scheme->wmarks.high || scheme->wmarks.low > metric) {

		if (scheme->wmarks.activated)