Commit b5bbe9c0 authored by SeongJae Park's avatar SeongJae Park Committed by Andrew Morton
Browse files

mm/damon: ask apply_scheme() to report filter-passed region-internal bytes 

Some DAMOS filter types including those for young page, anon page, and
belonging memcg are handled by underlying DAMON operations set
implementation, via damon_operations->apply_scheme() interface.  How many
bytes of the region have passed the filter can be useful for DAMOS scheme
tuning and access pattern monitoring.  Modify the interface to let the
callback implementation reports back the number if possible.

Link: https://lkml.kernel.org/r/20250106193401.109161-5-sj@kernel.org


Signed-off-by: default avatarSeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent fc4e4093

include/linux/damon.h

+3 −2
Original line number Diff line number Diff line
@@ -529,7 +529,8 @@ enum damon_ops_id { 
 * @apply_scheme is called from @kdamond when a region for user provided

 * DAMON-based operation scheme is found.  It should apply the scheme's action

 * to the region and return bytes of the region that the action is successfully

 * applied.

 * applied.  It should also report how many bytes of the region has passed

 * filters (&struct damos_filter) that handled by itself.

 * @target_valid should check whether the target is still valid for the

 * monitoring.

 * @cleanup is called from @kdamond just before its termination.
@@ -546,7 +547,7 @@ struct damon_operations { 
			struct damos *scheme);

	unsigned long (*apply_scheme)(struct damon_ctx *context,

			struct damon_target *t, struct damon_region *r,

			struct damos *scheme);

			struct damos *scheme, unsigned long *sz_filter_passed);

	bool (*target_valid)(struct damon_target *t);

	void (*cleanup)(struct damon_ctx *context);

};

mm/damon/core.c

+3 −1
Original line number Diff line number Diff line
@@ -1523,6 +1523,7 @@ static void damos_apply_scheme(struct damon_ctx *c, struct damon_target *t, 
	unsigned long sz = damon_sz_region(r);

	struct timespec64 begin, end;

	unsigned long sz_applied = 0;

	unsigned long sz_ops_filter_passed = 0;

	int err = 0;

	/*

	 * We plan to support multiple context per kdamond, as DAMON sysfs
@@ -1568,7 +1569,8 @@ static void damos_apply_scheme(struct damon_ctx *c, struct damon_target *t, 
		if (!err) {

			trace_damos_before_apply(cidx, sidx, tidx, r,

					damon_nr_regions(t), do_trace);

			sz_applied = c->ops.apply_scheme(c, t, r, s);

			sz_applied = c->ops.apply_scheme(c, t, r, s,

					&sz_ops_filter_passed);

		}

		damos_walk_call_walk(c, t, r, s);

		ktime_get_coarse_ts64(&end);

mm/damon/paddr.c

+1 −1
Original line number Diff line number Diff line
@@ -477,7 +477,7 @@ static unsigned long damon_pa_migrate(struct damon_region *r, struct damos *s) 


static unsigned long damon_pa_apply_scheme(struct damon_ctx *ctx,

		struct damon_target *t, struct damon_region *r,

		struct damos *scheme)

		struct damos *scheme, unsigned long *sz_filter_passed)

{

	switch (scheme->action) {

	case DAMOS_PAGEOUT:

mm/damon/vaddr.c

+1 −1
Original line number Diff line number Diff line
@@ -655,7 +655,7 @@ static unsigned long damos_madvise(struct damon_target *target, 


static unsigned long damon_va_apply_scheme(struct damon_ctx *ctx,

		struct damon_target *t, struct damon_region *r,

		struct damos *scheme)

		struct damos *scheme, unsigned long *sz_filter_passed)

{

	int madv_action;