The patch titled Subject: mm/damon/sysfs: use damos_walk() for update_schemes_tried_{bytes,regions} has been added to the -mm mm-unstable branch. Its filename is mm-damon-sysfs-use-damos_walk-for-update_schemes_tried_bytesregions.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-damon-sysfs-use-damos_walk-for-update_schemes_tried_bytesregions.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: SeongJae Park <sj@xxxxxxxxxx> Subject: mm/damon/sysfs: use damos_walk() for update_schemes_tried_{bytes,regions} Date: Fri, 3 Jan 2025 09:43:59 -0800 DAMON sysfs interface uses damon_callback with its own complicated synchronization facility to handle update_schemes_tried_bytes and update_schemes_tried_regions commands. But damos_walk() can support the use case without the additional synchronizations. Convert the code to use damos_walk() instead. Link: https://lkml.kernel.org/r/20250103174400.54890-10-sj@xxxxxxxxxx Signed-off-by: SeongJae Park <sj@xxxxxxxxxx> Cc: Jonathan Corbet <corbet@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/damon/sysfs-common.h | 5 +++ mm/damon/sysfs-schemes.c | 48 +++++++++++++++++++++++++++++++++++++ mm/damon/sysfs.c | 43 +++++++++++++++++++++++++++++++++ 3 files changed, 96 insertions(+) --- a/mm/damon/sysfs.c~mm-damon-sysfs-use-damos_walk-for-update_schemes_tried_bytesregions +++ a/mm/damon/sysfs.c @@ -1512,6 +1512,45 @@ static int damon_sysfs_damon_call(int (* return damon_call(kdamond->damon_ctx, &call_control); } +struct damon_sysfs_schemes_walk_data { + struct damon_sysfs_kdamond *sysfs_kdamond; + bool total_bytes_only; +}; + +/* populate the region directory */ +static void damon_sysfs_schemes_tried_regions_upd_one(void *data, struct damon_ctx *ctx, + struct damon_target *t, struct damon_region *r, + struct damos *s) +{ + struct damon_sysfs_schemes_walk_data *walk_data = data; + struct damon_sysfs_kdamond *sysfs_kdamond = walk_data->sysfs_kdamond; + + damos_sysfs_populate_region_dir( + sysfs_kdamond->contexts->contexts_arr[0]->schemes, + ctx, t, r, s, walk_data->total_bytes_only); +} + +static int damon_sysfs_update_schemes_tried_regions( + struct damon_sysfs_kdamond *sysfs_kdamond, bool total_bytes_only) +{ + struct damon_sysfs_schemes_walk_data walk_data = { + .sysfs_kdamond = sysfs_kdamond, + .total_bytes_only = total_bytes_only, + }; + struct damos_walk_control control = { + .walk_fn = damon_sysfs_schemes_tried_regions_upd_one, + .data = &walk_data, + }; + struct damon_ctx *ctx = sysfs_kdamond->damon_ctx; + + if (!ctx) + return -EINVAL; + + damon_sysfs_schemes_clear_regions( + sysfs_kdamond->contexts->contexts_arr[0]->schemes); + return damos_walk(ctx, &control); +} + /* * damon_sysfs_handle_cmd() - Handle a command for a specific kdamond. * @cmd: The command to handle. @@ -1542,6 +1581,10 @@ static int damon_sysfs_handle_cmd(enum d case DAMON_SYSFS_CMD_UPDATE_SCHEMES_STATS: return damon_sysfs_damon_call( damon_sysfs_upd_schemes_stats, kdamond); + case DAMON_SYSFS_CMD_UPDATE_SCHEMES_TRIED_BYTES: + return damon_sysfs_update_schemes_tried_regions(kdamond, true); + case DAMON_SYSFS_CMD_UPDATE_SCHEMES_TRIED_REGIONS: + return damon_sysfs_update_schemes_tried_regions(kdamond, false); case DAMON_SYSFS_CMD_CLEAR_SCHEMES_TRIED_REGIONS: return damon_sysfs_schemes_clear_regions( kdamond->contexts->contexts_arr[0]->schemes); --- a/mm/damon/sysfs-common.h~mm-damon-sysfs-use-damos_walk-for-update_schemes_tried_bytesregions +++ a/mm/damon/sysfs-common.h @@ -55,6 +55,11 @@ bool damos_sysfs_regions_upd_done(void); int damon_sysfs_schemes_update_regions_stop(struct damon_ctx *ctx); +void damos_sysfs_populate_region_dir(struct damon_sysfs_schemes *sysfs_schemes, + struct damon_ctx *ctx, struct damon_target *t, + struct damon_region *r, struct damos *s, + bool total_bytes_only); + int damon_sysfs_schemes_clear_regions( struct damon_sysfs_schemes *sysfs_schemes); --- a/mm/damon/sysfs-schemes.c~mm-damon-sysfs-use-damos_walk-for-update_schemes_tried_bytesregions +++ a/mm/damon/sysfs-schemes.c @@ -2183,6 +2183,54 @@ static int damon_sysfs_before_damos_appl return 0; } +/** + * damos_sysfs_populate_region_dir() - Populate a schemes tried region dir. + * @sysfs_schemes: Schemes directory to populate regions directory. + * @ctx: Corresponding DAMON context. + * @t: DAMON target of @r. + * @r: DAMON region to populate the directory for. + * @s: Corresponding scheme. + * @total_bytes_only: Whether the request is for bytes update only. + * + * Called from DAMOS walk callback while holding damon_sysfs_lock. + */ +void damos_sysfs_populate_region_dir(struct damon_sysfs_schemes *sysfs_schemes, + struct damon_ctx *ctx, struct damon_target *t, + struct damon_region *r, struct damos *s, bool total_bytes_only) +{ + struct damos *scheme; + struct damon_sysfs_scheme_regions *sysfs_regions; + struct damon_sysfs_scheme_region *region; + int schemes_idx = 0; + + damon_for_each_scheme(scheme, ctx) { + if (scheme == s) + break; + schemes_idx++; + } + + /* user could have removed the scheme sysfs dir */ + if (schemes_idx >= sysfs_schemes->nr) + return; + + sysfs_regions = sysfs_schemes->schemes_arr[schemes_idx]->tried_regions; + sysfs_regions->total_bytes += r->ar.end - r->ar.start; + if (total_bytes_only) + return; + + region = damon_sysfs_scheme_region_alloc(r); + if (!region) + return; + list_add_tail(®ion->list, &sysfs_regions->regions_list); + sysfs_regions->nr_regions++; + if (kobject_init_and_add(®ion->kobj, + &damon_sysfs_scheme_region_ktype, + &sysfs_regions->kobj, "%d", + sysfs_regions->nr_regions++)) { + kobject_put(®ion->kobj); + } +} + /* * DAMON callback that called after each accesses sampling. While this * callback is registered, damon_sysfs_lock should be held to ensure the _ Patches currently in -mm which might be from sj@xxxxxxxxxx are samples-add-a-skeleton-of-a-sample-damon-module-for-working-set-size-estimation.patch samples-damon-wsse-start-and-stop-damon-as-the-user-requests.patch samples-damon-wsse-implement-working-set-size-estimation-and-logging.patch samples-damon-introduce-a-skeleton-of-a-smaple-damon-module-for-proactive-reclamation.patch samples-damon-prcl-implement-schemes-setup.patch replace-free-hugepage-folios-after-migration-fix-2.patch docs-admin-guide-mm-damon-usage-remove-damon-debugfs-interface-documentation.patch docs-mm-damon-design-update-for-removal-of-damon-debugfs-interface.patch selftests-damon-config-remove-configs-for-damon-debugfs-interface-selftests.patch selftests-damon-remove-tests-for-damon-debugfs-interface.patch kunit-configs-remove-configs-for-damon-debugfs-interface-tests.patch mm-damon-remove-damon-debugfs-interface-kunit-tests.patch mm-damon-remove-damon-debugfs-interface.patch mm-damon-sysfs-schemes-remove-unnecessary-schemes-existence-check-in-damon_sysfs_schemes_clear_regions.patch mm-damon-sysfs-handle-clear_schemes_tried_regions-from-damon-sysfs-context.patch mm-damon-core-introduce-damon_call.patch mm-damon-sysfs-use-damon_call-for-update_schemes_stats.patch mm-damon-sysfs-use-damon_call-for-commit_schemes_quota_goals.patch mm-damon-sysfs-use-damon_call-for-update_schemes_effective_quotas.patch mm-damon-core-implement-damos_walk.patch docs-mm-damon-design-document-damos-regions-walking.patch mm-damon-sysfs-use-damos_walk-for-update_schemes_tried_bytesregions.patch mm-damon-sysfs-remove-unused-code-for-schemes-tried-regions-update.patch