linux.git/mm/damon, branch v6.8

mm/damon/lru_sort: fix quota status loss due to online tunings

2024-02-20T22:20:50+00:00

For online parameters change, DAMON_LRU_SORT creates new schemes based on
latest values of the parameters and replaces the old schemes with the new
one.  When creating it, the internal status of the quotas of the old
schemes is not preserved.  As a result, charging of the quota starts from
zero after the online tuning.  The data that collected to estimate the
throughput of the scheme's action is also reset, and therefore the
estimation should start from the scratch again.  Because the throughput
estimation is being used to convert the time quota to the effective size
quota, this could result in temporal time quota inaccuracy.  It would be
recovered over time, though.  In short, the quota accuracy could be
temporarily degraded after online parameters update.

Fix the problem by checking the case and copying the internal fields for
the status.

Link: https://lkml.kernel.org/r/20240216194025.9207-3-sj@kernel.org
Fixes: 40e983cca927 ("mm/damon: introduce DAMON-based LRU-lists Sorting")
Signed-off-by: SeongJae Park 
Cc: 	[6.0+]
Signed-off-by: Andrew Morton

mm/damon/reclaim: fix quota stauts loss due to online tunings

2024-02-20T22:20:50+00:00

Patch series "mm/damon: fix quota status loss due to online tunings".

DAMON_RECLAIM and DAMON_LRU_SORT is not preserving internal quota status
when applying new user parameters, and hence could cause temporal quota
accuracy degradation.  Fix it by preserving the status.


This patch (of 2):

For online parameters change, DAMON_RECLAIM creates new scheme based on
latest values of the parameters and replaces the old scheme with the new
one.  When creating it, the internal status of the quota of the old
scheme is not preserved.  As a result, charging of the quota starts from
zero after the online tuning.  The data that collected to estimate the
throughput of the scheme's action is also reset, and therefore the
estimation should start from the scratch again.  Because the throughput
estimation is being used to convert the time quota to the effective size
quota, this could result in temporal time quota inaccuracy.  It would be
recovered over time, though.  In short, the quota accuracy could be
temporarily degraded after online parameters update.

Fix the problem by checking the case and copying the internal fields for
the status.

Link: https://lkml.kernel.org/r/20240216194025.9207-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20240216194025.9207-2-sj@kernel.org
Fixes: e035c280f6df ("mm/damon/reclaim: support online inputs update")
Signed-off-by: SeongJae Park 
Cc: 	[5.19+]
Signed-off-by: Andrew Morton

mm/damon/sysfs-schemes: handle schemes sysfs dir removal before commit_schemes_quota_goals

2024-02-20T22:20:49+00:00

'commit_schemes_quota_goals' command handler,
damos_sysfs_set_quota_scores() assumes the number of schemes sysfs
directory will be same to the number of schemes of the DAMON context.  The
assumption is wrong since users can remove schemes sysfs directories while
DAMON is running.  In the case, illegal memory accesses can happen.  Fix
it by checking the case.

Link: https://lkml.kernel.org/r/20240213023633.124928-1-sj@kernel.org
Fixes: d91beaa505a0 ("mm/damon/sysfs-schemes: implement a command for scheme quota goals only commit")
Signed-off-by: SeongJae Park 
Signed-off-by: Andrew Morton

mm/damon/core: check apply interval in damon_do_apply_schemes()

2024-02-20T22:20:47+00:00

kdamond_apply_schemes() checks apply intervals of schemes and avoid
further applying any schemes if no scheme passed its apply interval. 
However, the following schemes applying function, damon_do_apply_schemes()
iterates all schemes without the apply interval check.  As a result, the
shortest apply interval is applied to all schemes.  Fix the problem by
checking the apply interval in damon_do_apply_schemes().

Link: https://lkml.kernel.org/r/20240205201306.88562-1-sj@kernel.org
Fixes: 42f994b71404 ("mm/damon/core: implement scheme-specific apply interval")
Signed-off-by: SeongJae Park 
Cc: 	[6.7.x]
Signed-off-by: Andrew Morton

mm/damon/sysfs-schemes: fix wrong DAMOS tried regions update timeout setup

2024-02-08T05:20:36+00:00

DAMON sysfs interface's update_schemes_tried_regions command has a timeout
of two apply intervals of the DAMOS scheme.  Having zero value DAMOS
scheme apply interval means it will use the aggregation interval as the
value.  However, the timeout setup logic is mistakenly using the sampling
interval insted of the aggregartion interval for the case.  This could
cause earlier-than-expected timeout of the command.  Fix it.

Link: https://lkml.kernel.org/r/20240202191956.88791-1-sj@kernel.org
Fixes: 7d6fa31a2fd7 ("mm/damon/sysfs-schemes: add timeout for update_schemes_tried_regions")
Signed-off-by: SeongJae Park 
Cc:  # 6.7.x
Signed-off-by: Andrew Morton

mm/damon/vaddr: change asm-generic/mman-common.h to linux/mman.h

2023-12-29T19:58:57+00:00

asm-generic/mman-common.h can be replaced by linux/mman.h and the file
will still build correctly.  It is an asm-generic file which should be
avoided if possible.

Link: https://lkml.kernel.org/r/20231221-asmgenericvaddr-v1-1-742b170c914e@google.com
Fixes: 6dea8add4d28 ("mm/damon/vaddr: support DAMON-based Operation Schemes")
Signed-off-by: Tanzir Hasan 
Suggested-by: Al Viro 
Reviewed-by: SeongJae Park 
Signed-off-by: Andrew Morton

mm/damon/core-test: test max_nr_accesses overflow caused divide-by-zero

2023-12-20T22:48:13+00:00

Commit 35f5d94187a6 ("mm/damon: implement a function for max nr_accesses
safe calculation") has fixed an overflow bug that could cause
divide-by-zero.  Add a kunit test for the bug to ensure similar bugs are
not introduced again.

Link: https://lkml.kernel.org/r/20231213190338.54146-3-sj@kernel.org
Signed-off-by: SeongJae Park 
Cc: Jonathan Corbet 
Signed-off-by: Andrew Morton

mm/damon: update email of SeongJae

2023-12-20T22:48:13+00:00

Patch series "mm/damon: misc updates for 6.8".

Update comments, tests, and documents for DAMON.


This patch (of 6):

SeongJae is using his kernel.org account for DAMON development.  Update
the old email addresses on the comments of DAMON source files.

Link: https://lkml.kernel.org/r/20231213190338.54146-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20231213190338.54146-2-sj@kernel.org
Signed-off-by: SeongJae Park 
Cc: Jonathan Corbet 
Signed-off-by: Andrew Morton

sync mm-stable with mm-hotfixes-stable to pick up depended-upon changes

2023-12-20T22:47:18+00:00

mm/damon/core: make damon_start() waits until kdamond_fn() starts

2023-12-13T01:20:17+00:00

The cleanup tasks of kdamond threads including reset of corresponding
DAMON context's ->kdamond field and decrease of global nr_running_ctxs
counter is supposed to be executed by kdamond_fn().  However, commit
0f91d13366a4 ("mm/damon: simplify stop mechanism") made neither
damon_start() nor damon_stop() ensure the corresponding kdamond has
started the execution of kdamond_fn().

As a result, the cleanup can be skipped if damon_stop() is called fast
enough after the previous damon_start().  Especially the skipped reset
of ->kdamond could cause a use-after-free.

Fix it by waiting for start of kdamond_fn() execution from
damon_start().

Link: https://lkml.kernel.org/r/20231208175018.63880-1-sj@kernel.org
Fixes: 0f91d13366a4 ("mm/damon: simplify stop mechanism")
Signed-off-by: SeongJae Park 
Reported-by: Jakub Acs 
Cc: Changbin Du 
Cc: Jakub Acs 
Cc:  # 5.15.x
Signed-off-by: Andrew Morton