linux/mm/damon
SeongJae Park c603c630b5 mm/damon/core: add a tracepoint for damos apply target regions
Patch series "mm/damon: add a tracepoint for damos apply target regions",
v2.

DAMON provides damon_aggregated tracepoint to let users record full
monitoring results.  Sometimes, users need to record monitoring results of
specific pattern.  DAMOS tried regions directory of DAMON sysfs interface
allows it, but the interface is mainly designed for snapshots and
therefore would be inefficient for such recording.  Implement yet another
tracepoint for efficient support of the usecase.


This patch (of 2):

DAMON provides damon_aggregated tracepoint, which exposes details of each
region and its access monitoring results.  It is useful for getting whole
monitoring results, e.g., for recording purposes.

For investigations of DAMOS, DAMON Sysfs interface provides DAMOS
statistics and tried_regions directory.  But, those provides only
statistics and snapshots.  If the scheme is frequently applied and if the
user needs to know every detail of DAMOS behavior, the snapshot-based
interface could be insufficient and expensive.

As a last resort, userspace users need to record the all monitoring
results via damon_aggregated tracepoint and simulate how DAMOS would
worked.  It is unnecessarily complicated.  DAMON kernel API users,
meanwhile, can do that easily via before_damos_apply() callback field of
'struct damon_callback', though.

Add a tracepoint that will be called just after before_damos_apply()
callback for more convenient investigations of DAMOS.  The tracepoint
exposes all details about each regions, similar to damon_aggregated
tracepoint.

Please note that DAMOS is currently not only for memory management but
also for query-like efficient monitoring results retrievals (when 'stat'
action is used).  Until now, only statistics or snapshots were supported. 
Addition of this tracepoint allows efficient full recording of DAMOS-based
filtered monitoring results.

Link: https://lkml.kernel.org/r/20230913022050.2109-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20230913022050.2109-2-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>	[tracing]
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-04 10:32:28 -07:00
..
core-test.h mm/damon/core-test: add a unit test for __damos_filter_out() 2023-08-21 13:37:35 -07:00
core.c mm/damon/core: add a tracepoint for damos apply target regions 2023-10-04 10:32:28 -07:00
dbgfs-test.h mm/damon/dbgfs-test: fix is_target_id() change 2022-03-22 15:57:12 -07:00
dbgfs.c mm/damon/dbgfs: print DAMON debugfs interface deprecation message 2023-02-13 15:54:33 -08:00
Kconfig mm/damon/Kconfig: add DAMON debugfs interface deprecation notice 2023-02-13 15:54:32 -08:00
lru_sort.c mm/damon: use kstrtobool() instead of strtobool() 2022-11-30 15:58:45 -08:00
Makefile mm/damon/modules: deduplicate init steps for DAMON context setup 2022-11-30 15:01:26 -08:00
modules-common.c mm/damon/modules: deduplicate init steps for DAMON context setup 2022-11-30 15:01:26 -08:00
modules-common.h mm/damon/modules: deduplicate init steps for DAMON context setup 2022-11-30 15:01:26 -08:00
ops-common.c damon: use pmdp_get instead of drectly dereferencing pmd 2023-08-21 13:37:30 -07:00
ops-common.h mm/damon/ops-common: atomically test and clear young on ptes and pmds 2023-06-09 16:25:55 -07:00
paddr.c damon: use pmdp_get instead of drectly dereferencing pmd 2023-08-21 13:37:30 -07:00
reclaim.c mm/damon/reclaim: add a parameter called skip_anon for avoiding anonymous pages reclamation 2023-01-18 17:12:43 -08:00
sysfs-common.c mm/damon/sysfs: make kobj_type structures constant 2023-02-09 16:51:45 -08:00
sysfs-common.h mm/damon/sysfs: implement a command for updating only schemes tried total bytes 2023-08-21 13:37:34 -07:00
sysfs-schemes.c mm/damon/sysfs-schemes: support target damos filter 2023-08-21 13:37:37 -07:00
sysfs.c mm/damon/sysfs: implement a command for updating only schemes tried total bytes 2023-08-21 13:37:34 -07:00
vaddr-test.h mm/damon/vaddr-test: fix memory leak in damon_do_test_apply_three_regions() 2023-09-29 17:20:47 -07:00
vaddr.c mm: hugetlb: add huge page size param to set_huge_pte_at() 2023-09-29 17:20:47 -07:00