From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 153531E89C; Tue, 17 Mar 2026 00:07:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773706046; cv=none; b=A6q6w6gASVVoGpEER1Ian6POfjkpHNgon2ByXnqOAhYg2xp2lvZiL/5ZEc9VVUuhU3hzHhsohh8siKF98X1QFBjIPDGKUy4WPPN0fC+U2rty3gPMUfHzaJEbXEj4qoMMA8QC2cyXh5i+B5oU5uGPbzjOYf4InPQp+bwLP7BtdFo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773706046; c=relaxed/simple; bh=fUhFgpEwmhk31MCVLxtOxFsZwhhVbi9LIUg7DBg+IAY=; h=Date:To:From:Subject:Message-Id; b=a2l/4ccQluQ6p7f8UdSubGnahqbCiSHn/CnvnwCRFUqkZ9LlKOawaJZcl9tkINNgmKj/EZInz+xh67mZxtM0rMxHs1dKYg6ZPsi7CJ4yk+i0So2WjL3FZn+AkY6FmQfZhZ5BHA/Pdd8Sy0HelGBHWafjnYFLnuWHpDdmLQY7Vgc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=tfN8hF1B; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="tfN8hF1B" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C2425C19421; Tue, 17 Mar 2026 00:07:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1773706045; bh=fUhFgpEwmhk31MCVLxtOxFsZwhhVbi9LIUg7DBg+IAY=; h=Date:To:From:Subject:From; b=tfN8hF1BpIPh38i/nyh807W+RhkATCgxalqfwINmIa82/M8N5hUrmVUCQau8fpcUb 0IJ16dNG4jILA+cpqMkgDSQEauA5pSRy95/ovO8VuSDQ7nES5FwWG8efqEGu8DURIF nz1v38R5choCvGlK/LeO4ubueaPEo9XDitIz6o/A= Date: Mon, 16 Mar 2026 17:07:25 -0700 To: mm-commits@vger.kernel.org,stable@vger.kernel.org,sj@kernel.org,akpm@linux-foundation.org From: Andrew Morton Subject: + mm-damon-stat-monitor-all-system-ram-resources.patch added to mm-hotfixes-unstable branch Message-Id: <20260317000725.C2425C19421@smtp.kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: mm/damon/stat: monitor all System RAM resources has been added to the -mm mm-hotfixes-unstable branch. Its filename is mm-damon-stat-monitor-all-system-ram-resources.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-damon-stat-monitor-all-system-ram-resources.patch This patch will later appear in the mm-hotfixes-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 various branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there most days ------------------------------------------------------ From: SeongJae Park Subject: mm/damon/stat: monitor all System RAM resources Date: Mon, 16 Mar 2026 16:51:17 -0700 DAMON_STAT usage document (Documentation/admin-guide/mm/damon/stat.rst) says it monitors the system's entire physical memory. But, it is monitoring only the biggest System RAM resource of the system. When there are multiple System RAM resources, this results in monitoring only an unexpectedly small fraction of the physical memory. For example, suppose the system has a 500 GiB System RAM, 10 MiB non-System RAM, and 500 GiB System RAM resources in order on the physical address space. DAMON_STAT will monitor only the first 500 GiB System RAM. This situation is particularly common on NUMA systems. Select a physical address range that covers all System RAM areas of the system, to fix this issue and make it work as documented. Link: https://lkml.kernel.org/r/20260316235118.873-1-sj@kernel.org Fixes: 369c415e6073 ("mm/damon: introduce DAMON_STAT module") Signed-off-by: SeongJae Park Cc: [6.17+] Signed-off-by: Andrew Morton --- mm/damon/stat.c | 51 +++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 48 insertions(+), 3 deletions(-) --- a/mm/damon/stat.c~mm-damon-stat-monitor-all-system-ram-resources +++ a/mm/damon/stat.c @@ -145,12 +145,57 @@ static int damon_stat_damon_call_fn(void return 0; } +struct damon_stat_system_ram_range_walk_arg { + bool walked; + struct resource res; +}; + +static int damon_stat_system_ram_walk_fn(struct resource *res, void *arg) +{ + struct damon_stat_system_ram_range_walk_arg *a = arg; + + if (!a->walked) { + a->walked = true; + a->res.start = res->start; + } + a->res.end = res->end; + return 0; +} + +static unsigned long damon_stat_res_to_core_addr(resource_size_t ra, + unsigned long addr_unit) +{ + /* + * Use div_u64() for avoiding linking errors related with __udivdi3, + * __aeabi_uldivmod, or similar problems. This should also improve the + * performance optimization (read div_u64() comment for the detail). + */ + if (sizeof(ra) == 8 && sizeof(addr_unit) == 4) + return div_u64(ra, addr_unit); + return ra / addr_unit; +} + +static int damon_stat_set_monitoring_region(struct damon_target *t, + unsigned long addr_unit, unsigned long min_region_sz) +{ + struct damon_addr_range addr_range; + struct damon_stat_system_ram_range_walk_arg arg = {}; + + walk_system_ram_res(0, -1, &arg, damon_stat_system_ram_walk_fn); + if (!arg.walked) + return -EINVAL; + addr_range.start = damon_stat_res_to_core_addr( + arg.res.start, addr_unit); + addr_range.end = damon_stat_res_to_core_addr( + arg.res.end + 1, addr_unit); + return damon_set_regions(t, &addr_range, 1, min_region_sz); +} + static struct damon_ctx *damon_stat_build_ctx(void) { struct damon_ctx *ctx; struct damon_attrs attrs; struct damon_target *target; - unsigned long start = 0, end = 0; ctx = damon_new_ctx(); if (!ctx) @@ -180,8 +225,8 @@ static struct damon_ctx *damon_stat_buil if (!target) goto free_out; damon_add_target(ctx, target); - if (damon_set_region_biggest_system_ram_default(target, &start, &end, - ctx->min_region_sz)) + if (damon_stat_set_monitoring_region(target, ctx->addr_unit, + ctx->min_region_sz)) goto free_out; return ctx; free_out: _ Patches currently in -mm which might be from sj@kernel.org are mm-damon-stat-monitor-all-system-ram-resources.patch mm-damon-core-set-quota-score-histogram-with-core-filters.patch mm-damon-core-do-non-safe-region-walk-on-kdamond_apply_schemes.patch mm-damon-core-split-regions-for-min_nr_regions.patch mm-damon-vaddr-do-not-split-regions-for-min_nr_regions.patch mm-damon-test-core-kunit-add-damon_apply_min_nr_regions-test.patch mm-damon-add-config_damon_debug_sanity.patch mm-damon-core-add-damon_new_region-debug_sanity-check.patch mm-damon-core-add-damon_del_region-debug_sanity-check.patch mm-damon-core-add-damon_nr_regions-debug_sanity-check.patch mm-damon-core-add-damon_merge_two_regions-debug_sanity-check.patch mm-damon-core-add-damon_merge_regions_of-debug_sanity-check.patch mm-damon-core-add-damon_split_region_at-debug_sanity-check.patch mm-damon-core-add-damon_reset_aggregated-debug_sanity-check.patch mm-damon-tests-kunitconifg-enable-damon_debug_sanity.patch selftests-damon-config-enable-damon_debug_sanity.patch mm-damon-tests-core-kunit-add-a-test-for-damon_commit_ctx.patch docs-mm-damon-design-document-the-power-of-two-limitation-for-addr_unit.patch mm-damon-core-remove-damos_set_next_apply_sis-duplicates.patch mm-damon-core-use-time_before-for-next_apply_sis.patch mm-damon-core-use-time_after_eq-in-kdamond_fn.patch mm-damon-core-use-mult_frac.patch mm-damon-tests-core-kunit-add-a-test-for-damon_is_last_region.patch mm-damon-core-clarify-damon_set_attrs-usages.patch mm-damon-document-non-zero-length-damon_region-assumption.patch docs-admin-guide-mm-damn-lru_sort-fix-intervals-autotune-parameter-name.patch docs-mm-damon-maintainer-profile-use-flexible-review-cadence.patch docs-mm-damon-index-fix-typo-autoamted-automated.patch mm-damon-core-introduce-damos_quota_goal_tuner.patch mm-damon-core-allow-quota-goals-set-zero-effective-size-quota.patch mm-damon-core-introduce-damos_quota_goal_tuner_temporal.patch mm-damon-sysfs-schemes-implement-quotas-goal_tuner-file.patch docs-mm-damon-design-document-the-goal-based-quota-tuner-selections.patch docs-admin-guide-mm-damon-usage-document-goal_tuner-sysfs-file.patch docs-abi-damon-update-for-goal_tuner.patch mm-damon-tests-core-kunit-test-goal_tuner-commit.patch selftests-damon-_damon_sysfs-support-goal_tuner-setup.patch selftests-damon-drgn_dump_damon_status-support-quota-goal_tuner-dumping.patch selftests-damon-sysfspy-test-goal_tuner-commit.patch mm-damon-core-fix-wrong-end-address-assignment-on-walk_system_ram.patch mm-damon-core-support-addr_unit-on-damon_find_biggest_system_ram.patch mm-damon-core-receive-addr_unit-on-damon_set_region_biggest_system_ram_default.patch mm-damon-core-receive-addr_unit-on-damon_set_region_biggest_system_ram_default-fix.patch mm-damon-reclaim-respect-addr_unit-on-default-monitoring-region-setup.patch mm-damon-lru_sort-respect-addr_unit-on-default-monitoring-region-setup.patch