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 BE2AE33B6F6; Mon, 18 May 2026 23:41:25 +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=1779147685; cv=none; b=Rh82I7POqI1Kwju5wHzN9MGIC3GrMrPHBHF+OezSZKmsbfXcWIWpii2nWrjkdLKblmiyS2N4hz+K9y8swHh7fCfGppFKY4G8FzYaQmAry53PfpH8EILTVkCdmZ8j/lhwlJLhozVbCgNrmtpAEOP6mkxqBie2F4DaOL9nulB9GFQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779147685; c=relaxed/simple; bh=IlAa+oqmEJU7Ymj9l5zZPzJiXY56Jh7uaI0GPCOUdHo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=i1j+B0IfDUae4JXGOhU7d9BwI2NPOCv7GFI9cMYHTLcwmQkgmZL0oEgpiUCQankTRn1E1aqNvt4pJtwdwHEuqYY2eOK+wmcOZh82zopOA6lzU2difp0FSzawyN7pQivGl5bRCrZSKkBVWk/Sdy7jVlEldXfEZ9koeUlwy3laX+c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=S0aaBZ+u; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="S0aaBZ+u" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 75EEAC2BCC7; Mon, 18 May 2026 23:41:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1779147685; bh=IlAa+oqmEJU7Ymj9l5zZPzJiXY56Jh7uaI0GPCOUdHo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=S0aaBZ+unVDLD6djSWl/RinRsUhT4XjzyZT+8HeKoPgKZFTIU3hPnRzNfN0tRHS5e XM1/wiof5kJ4tPvwnaEKHbPjWBgIM0s/kVvxT0wwiLkePbg1ZAfloJ6vWZ2zWr5vwH TVRU7dgoR43P6zQvZzYlLU19c/8Jt70XTejnr3o28qQvbwVALZvvHWGBPGQo7gfyD9 EOgavJelUGc2RYXHMFbmcZBPDiG12ZxETMmqARfJ8k6eYE9idwqiF38DFWsPsvH79e EHfhcVcDfp4mFU8SSihbsBUU/rk/zDpiGxvFsoqZ80Cdr6WZpFESqm3s5GkpCvPdYO wkes1E00GUpVA== From: SeongJae Park To: Andrew Morton Cc: SeongJae Park , damon@lists.linux.dev, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH 05/28] mm/damon/core: introduce damon_region->probe_hits Date: Mon, 18 May 2026 16:40:53 -0700 Message-ID: <20260518234119.97569-6-sj@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260518234119.97569-1-sj@kernel.org> References: <20260518234119.97569-1-sj@kernel.org> Precedence: bulk X-Mailing-List: damon@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Add an array for the per-region per-probe positive samples count. For simple and efficient implementation, add a limit to the number of data probes and set the array to support only the limited number of counters. Signed-off-by: SeongJae Park --- include/linux/damon.h | 4 ++++ mm/damon/core.c | 10 ++++++++++ 2 files changed, 14 insertions(+) diff --git a/include/linux/damon.h b/include/linux/damon.h index f8b679dd944d9..3a30af119ac6e 100644 --- a/include/linux/damon.h +++ b/include/linux/damon.h @@ -17,6 +17,8 @@ /* Minimal region size. Every damon_region is aligned by this. */ #define DAMON_MIN_REGION_SZ PAGE_SIZE +/* Maximum number of monitoring probes. */ +#define DAMON_MAX_PROBES (4) /* Max priority score for DAMON-based operation schemes */ #define DAMOS_MAX_SCORE (99) @@ -47,6 +49,7 @@ struct damon_size_range { * @nr_accesses: Access frequency of this region. * @nr_accesses_bp: @nr_accesses in basis point (0.01%) that updated for * each sampling interval. + * @probe_hits: Number of probe-positive region samples. * @list: List head for siblings. * @age: Age of this region. * @@ -75,6 +78,7 @@ struct damon_region { unsigned long sampling_addr; unsigned int nr_accesses; unsigned int nr_accesses_bp; + unsigned char probe_hits[DAMON_MAX_PROBES]; struct list_head list; unsigned int age; diff --git a/mm/damon/core.c b/mm/damon/core.c index 075d60a4749a3..6dd1bce81ec2a 100644 --- a/mm/damon/core.c +++ b/mm/damon/core.c @@ -229,6 +229,7 @@ static void damon_verify_new_region(unsigned long start, unsigned long end) struct damon_region *damon_new_region(unsigned long start, unsigned long end) { struct damon_region *region; + int i; damon_verify_new_region(start, end); region = kmem_cache_alloc(damon_region_cache, GFP_KERNEL); @@ -239,6 +240,8 @@ struct damon_region *damon_new_region(unsigned long start, unsigned long end) region->ar.end = end; region->nr_accesses = 0; region->nr_accesses_bp = 0; + for (i = 0; i < DAMON_MAX_PROBES; i++) + region->probe_hits[i] = 0; INIT_LIST_HEAD(®ion->list); region->age = 0; @@ -2983,12 +2986,17 @@ static void damon_merge_two_regions(struct damon_target *t, struct damon_region *l, struct damon_region *r) { unsigned long sz_l = damon_sz_region(l), sz_r = damon_sz_region(r); + int i; l->nr_accesses = (l->nr_accesses * sz_l + r->nr_accesses * sz_r) / (sz_l + sz_r); l->nr_accesses_bp = l->nr_accesses * 10000; l->age = (l->age * sz_l + r->age * sz_r) / (sz_l + sz_r); l->ar.end = r->ar.end; + /* todo: do this for only installed probes */ + for (i = 0; i < DAMON_MAX_PROBES; i++) + l->probe_hits[i] = (l->probe_hits[i] * sz_l + r->probe_hits[i] + * sz_r) / (sz_l + sz_r); damon_verify_merge_two_regions(l, r); damon_destroy_region(r, t); } @@ -3111,6 +3119,8 @@ static void damon_split_region_at(struct damon_target *t, new->last_nr_accesses = r->last_nr_accesses; new->nr_accesses_bp = r->nr_accesses_bp; new->nr_accesses = r->nr_accesses; + /* todo: do this for only installed probes */ + memcpy(new->probe_hits, r->probe_hits, sizeof(r->probe_hits)); damon_insert_region(new, r, damon_next_region(r), t); } -- 2.47.3