mm/damon/sysfs: handle 'state' file inputs for every sampling interval if possible

DAMON sysfs interface need to access kdamond-touching data for some of
kdamond user commands.  It uses ->after_aggregation() kdamond callback to
safely access the data in the case.  It had to use the aggregation
interval callback because that was the only callback that users can access
complete monitoring results.

Since patch series "mm/damon: provide pseudo-moving sum based access
rate", which starts from commit 78fbfb155d20 ("mm/damon/core: define and
use a dedicated function for region access rate update"), DAMON provides
good-to-use quality moitoring results for every sampling interval.  It
aims to help users who need to quickly retrieve the monitoring results. 
When the aggregation interval is set too long and therefore waiting for
the aggregation interval can degrade user experience, or when the access
pattern is expected to be significantly changed[1] could be such cases.

However, because DAMON sysfs interface is still handling the commands per
aggregation interval, the end user cannot get the benefit.  Update DAMON
sysfs interface to handle kdamond commands for every sampling interval if
applicable.  Specifically, all kdamond data accessing commands except
'commit' command are applicable.

[1] https://lore.kernel.org/r/20240129121316.GA9706@cuiyangpei

Link: https://lkml.kernel.org/r/20240206025158.203097-1-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: xiongping1 <xiongping1@xiaomi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/mm/damon/sysfs-common.h b/mm/damon/sysfs-common.h
index 4c37a166eb81..ec0703e1e90b 100644
--- a/mm/damon/sysfs-common.h
+++ b/mm/damon/sysfs-common.h
@@ -49,6 +49,8 @@ int damon_sysfs_schemes_update_regions_start(
 		struct damon_sysfs_schemes *sysfs_schemes,
 		struct damon_ctx *ctx, bool total_bytes_only);
 
+void damos_sysfs_mark_finished_regions_updates(struct damon_ctx *ctx);
+
 bool damos_sysfs_regions_upd_done(void);
 
 int damon_sysfs_schemes_update_regions_stop(struct damon_ctx *ctx);