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 496383FCB2B; Thu, 14 May 2026 14:09:20 +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=1778767760; cv=none; b=RrUXWumHFoTmzL/QXrxw/4IsZEKvIZ0VAbcb524PNVSBkaQETLkL7m08iJLJdYAI4qG34SnH2fqh4lWDdG57Kg721m8vDBwi3p87Zxeh1um6LVNDggOzzpRoHC685oP07aBqJN7FfHKssqoATUPkL4GmXcB3ReCj/5cczQiLndo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778767760; c=relaxed/simple; bh=sqTfJo5eyZfIgPieldGgPDsesotOxkPfGODr6Semhvg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=JFIT+cpxLIbpC+2V1xK+LvnT4ZoUIuo7I/NgqhQogmEc113kHbDuMsAHlPR5ylgi5PNiF3OkeDnLZTU8ASJgGepiF4ETC56E1OjkaSxHmBfdB25lmewrrrIvq1iGus3HEsO/u76iyFalxF2SQQ30JTT4CQWdTvCn1JQq9OSa81o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=APmAy3P3; 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="APmAy3P3" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C46CBC2BCB3; Thu, 14 May 2026 14:09:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1778767760; bh=sqTfJo5eyZfIgPieldGgPDsesotOxkPfGODr6Semhvg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=APmAy3P3zBWWFCtHrCjRInzPQ1wTdfZiuTcr4UgvclDr3G/3mLnO+A8yEQpSfp+Ln aVSCANxtL7H/yq1Cpn8hD4qSvJwdYArBsVTmlP4pDQP1ROZ+T5zNoehnpJN2nYW678 6CidkqI4pJpO9JEOzFgdUJpmuChQQKHhXf5H4T9tBp/pSb27XThlF28DfQZrLl9ucE HPMG545QEjaH9tVeBDwR5ojKnM0LNjudL47QTwh05ZF5lmKl1zBAuKDg1gGDTE0dgR YlX2PDw1vAKRY+Asr5W+LREqIWXX6peVO4ruvKeLQVMccS33zyECscvz2KeFkk/U2L oUk73SfHPQ0/A== From: SeongJae Park To: Cc: SeongJae Park , Andrew Morton , damon@lists.linux.dev, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [RFC PATCH v2.1 05/28] mm/damon/core: introduce damon_region->probe_hits Date: Thu, 14 May 2026 07:08:38 -0700 Message-ID: <20260514140904.119781-6-sj@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260514140904.119781-1-sj@kernel.org> References: <20260514140904.119781-1-sj@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org 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 | 3 +++ 2 files changed, 7 insertions(+) diff --git a/include/linux/damon.h b/include/linux/damon.h index 95b2c508a63ea..19b780bfab051 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 240cae1420c12..72acdeb8c478e 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; -- 2.47.3