From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 028993B6BF1; Fri, 19 Jun 2026 19:34:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781897688; cv=none; b=peHSisKhuJHJj54c/b6nS8QfoMrlSpJVRGrlG2Y+Fxs/cjvn5+Zo5eyUSGvm2JWFmzn/Ep8nD/C583VPAcR56iuFDuYp4iB0hGFK3BN0jysTl+L3v4Kd8XyYN3+YgnhgwpJxdH71PAJsqohCywWTOXUouJ0pKniVBRH2qshPyzM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781897688; c=relaxed/simple; bh=bgLBJ/GXUsvrTf/mTcATgHkmM5FCU8gZ+FjIy9Cv2o8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=QbpAqU2j7OqbDu9apKpgasqShPDilyrMZyueXnLhcSDnJy+3B6NDlRNsEK2428XKhPDCcPaNGFIaWuTOpgLokoQhvA6YNnvujsNYZwBH64kQ/Di3bXn3OgxYeXZ6Gc8KdcngagDcdmRSkcdOCSKJOJT4syNi+Qy5PN/GGgTfF88= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=b9PKAF4z; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="b9PKAF4z" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1B0331F00A3D; Fri, 19 Jun 2026 19:34:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1781897683; bh=Mj0WGbOgmW24rBedByuWyQfl2j0/cU9b+G44I09HpLc=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=b9PKAF4zEoqNsBbqOMqLn6VEvkGq+pyOY+0V/lEGTXhoofxVS5wFTR/lAyQIoohew jzQKCOhleBfcyiZeJOBxZx3t0g2IMJJEYX9f28XoCBL/5WGhKrIkRL/2LTsg7l6N/v OWdDCzIkP4QIVGZuDFQhOdDpalUEPF7RO+FkK9iGIr1MnOMEC4KdoDaIUWcKzftY9Q cGeIsI0WZWFVfV9scjXpfhTNGKOY6Cy2u+K51r5zGs9PNB4LgnDEnRjmu2U1j60Knv EDdJy7d5r667Skm2KKzVlIVvfGlSVdKyF/Kc9eMMJappjIBqUYDaflGWoGjr3CXA5A SDkMnZHhArPTQ== 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 11/13] mm/damon/core: remove nr_accesses_bp setups and updates Date: Fri, 19 Jun 2026 12:33:56 -0700 Message-ID: <20260619193415.73833-12-sj@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260619193415.73833-1-sj@kernel.org> References: <20260619193415.73833-1-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 DAMON core sets and updates nr_accesses_bp in multiple places. It explains how delicate it is. The field is no more being used for any real purpose, and replaced by a simpler function. Remove the setups and updates. Signed-off-by: SeongJae Park --- mm/damon/core.c | 17 ----------------- 1 file changed, 17 deletions(-) diff --git a/mm/damon/core.c b/mm/damon/core.c index f2db39aa34f4c..eb129e3f7029d 100644 --- a/mm/damon/core.c +++ b/mm/damon/core.c @@ -294,7 +294,6 @@ struct damon_region *damon_new_region(unsigned long start, unsigned long end) region->ar.start = start; 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); @@ -869,7 +868,6 @@ static void damon_update_monitoring_result(struct damon_region *r, if (!aggregating) { r->nr_accesses = damon_nr_accesses_for_new_attrs( r->nr_accesses, old_attrs, new_attrs); - r->nr_accesses_bp = r->nr_accesses * 10000; } else { /* * if this is called in the middle of the aggregation, reset @@ -879,7 +877,6 @@ static void damon_update_monitoring_result(struct damon_region *r, */ r->last_nr_accesses = damon_nr_accesses_for_new_attrs( r->last_nr_accesses, old_attrs, new_attrs); - r->nr_accesses_bp = r->last_nr_accesses * 10000; r->nr_accesses = 0; } r->age = damon_age_for_new_attrs(r->age, old_attrs, new_attrs); @@ -3096,7 +3093,6 @@ static void damon_merge_two_regions(struct damon_target *t, 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 */ @@ -3208,7 +3204,6 @@ static void damon_split_region_at(struct damon_target *t, new->age = r->age; 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)); @@ -3777,18 +3772,6 @@ static unsigned int damon_moving_sum(unsigned int mvsum, unsigned int nomvsum, void damon_update_region_access_rate(struct damon_region *r, bool accessed, struct damon_attrs *attrs) { - unsigned int len_window = 1; - - /* - * sample_interval can be zero, but cannot be larger than - * aggr_interval, owing to validation of damon_set_attrs(). - */ - if (attrs->sample_interval) - len_window = damon_max_nr_accesses(attrs); - r->nr_accesses_bp = damon_moving_sum(r->nr_accesses_bp, - r->last_nr_accesses * 10000, len_window, - accessed ? 10000 : 0); - if (accessed) r->nr_accesses++; } -- 2.47.3