From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C0016C38A2D for ; Mon, 24 Oct 2022 22:29:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230519AbiJXW2u (ORCPT ); Mon, 24 Oct 2022 18:28:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43346 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231160AbiJXW2X (ORCPT ); Mon, 24 Oct 2022 18:28:23 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D32232738 for ; Mon, 24 Oct 2022 13:50:33 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 32DAD6156A for ; Mon, 24 Oct 2022 20:49:26 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 310FFC43470; Mon, 24 Oct 2022 20:49:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1666644565; bh=oUwwKx4MXojkoEQqGNX/HEaiCbrgYpcKgdZZJ/EkGWk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=uKMGy0G6jcaGd0zTpR25Gix/DSt03DjhqKeRS6R6ysGdjXdWs+7H8xeUlFIeCJL0h 1ZxJ0p4nufcgHwt0jkA1sdbhlmfhB8o9N7kOr7bjj4DkqYvDkvg5crypPti+m4h56x oF0ltzUpLlBpduDIF+VhIqEuEq5nCMFUJaEYGAIIdhdAt8LrvPpr7NjW6q+mFA5/Hy Nw3fO5k/IHl+lF7taJMHNRKazCaOw/prWaaR9srfa4y9bed5HaKoN+8Wian6/QXFlz wPeboMDnqzyY/Yul8HhGh+0cM5fGMK0fr43YGRhBHZlPVPlVPuY/PTj5SfIkl7G+7T XFkTH3jGPpLdw== From: SeongJae Park To: SeongJae Park , Andrew Morton Cc: damon@lists.linux.dev, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH 01/11] mm/damon/core: split out DAMOS-charged region skip logic into a new function Date: Mon, 24 Oct 2022 20:49:09 +0000 Message-Id: <20221024204919.18524-2-sj@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20221024204919.18524-1-sj@kernel.org> References: <20221024204919.18524-1-sj@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The DAMOS action applying function, 'damon_do_apply_schemes()', is quite long and not so simple. Split out the already quota-charged region skip code, which is not a small amount of simple code, into a new function with some comments for better readability. Signed-off-by: SeongJae Park --- mm/damon/core.c | 96 +++++++++++++++++++++++++++++++++---------------- 1 file changed, 65 insertions(+), 31 deletions(-) diff --git a/mm/damon/core.c b/mm/damon/core.c index 36d098d06c55..06b50ede9cc6 100644 --- a/mm/damon/core.c +++ b/mm/damon/core.c @@ -694,6 +694,67 @@ static bool damos_valid_target(struct damon_ctx *c, struct damon_target *t, return c->ops.get_scheme_score(c, t, r, s) >= s->quota.min_score; } +/* + * damos_skip_charged_region() - Check if the given region or starting part of + * it is already charged for the DAMOS quota. + * @t: The target of the region. + * @rp: The pointer to the region. + * @s: The scheme to be applied. + * + * If a quota of a scheme has exceeded in a quota charge window, the scheme's + * action would applied to only a part of the target access pattern fulfilling + * regions. To avoid applying the scheme action to only already applied + * regions, DAMON skips applying the scheme action to the regions that charged + * in the previous charge window. + * + * This function checks if a given region should be skipped or not for the + * reason. If only the starting part of the region has previously charged, + * this function splits the region into two so that the second one covers the + * area that not charged in the previous charge widnow and saves the second + * region in *rp and returns false, so that the caller can apply DAMON action + * to the second one. + * + * Return: true if the region should be entirely skipped, false otherwise. + */ +static bool damos_skip_charged_region(struct damon_target *t, + struct damon_region **rp, struct damos *s) +{ + struct damon_region *r = *rp; + struct damos_quota *quota = &s->quota; + unsigned long sz_to_skip; + + /* Skip previously charged regions */ + if (quota->charge_target_from) { + if (t != quota->charge_target_from) + return true; + if (r == damon_last_region(t)) { + quota->charge_target_from = NULL; + quota->charge_addr_from = 0; + return true; + } + if (quota->charge_addr_from && + r->ar.end <= quota->charge_addr_from) + return true; + + if (quota->charge_addr_from && r->ar.start < + quota->charge_addr_from) { + sz_to_skip = ALIGN_DOWN(quota->charge_addr_from - + r->ar.start, DAMON_MIN_REGION); + if (!sz_to_skip) { + if (damon_sz_region(r) <= DAMON_MIN_REGION) + return true; + sz_to_skip = DAMON_MIN_REGION; + } + damon_split_region_at(t, r, sz_to_skip); + r = damon_next_region(r); + *rp = r; + } + quota->charge_target_from = NULL; + quota->charge_addr_from = 0; + } + return false; +} + static void damon_do_apply_schemes(struct damon_ctx *c, struct damon_target *t, struct damon_region *r) @@ -702,7 +763,7 @@ static void damon_do_apply_schemes(struct damon_ctx *c, damon_for_each_scheme(s, c) { struct damos_quota *quota = &s->quota; - unsigned long sz = damon_sz_region(r); + unsigned long sz; struct timespec64 begin, end; unsigned long sz_applied = 0; @@ -713,41 +774,14 @@ static void damon_do_apply_schemes(struct damon_ctx *c, if (quota->esz && quota->charged_sz >= quota->esz) continue; - /* Skip previously charged regions */ - if (quota->charge_target_from) { - if (t != quota->charge_target_from) - continue; - if (r == damon_last_region(t)) { - quota->charge_target_from = NULL; - quota->charge_addr_from = 0; - continue; - } - if (quota->charge_addr_from && - r->ar.end <= quota->charge_addr_from) - continue; - - if (quota->charge_addr_from && r->ar.start < - quota->charge_addr_from) { - sz = ALIGN_DOWN(quota->charge_addr_from - - r->ar.start, DAMON_MIN_REGION); - if (!sz) { - if (damon_sz_region(r) <= - DAMON_MIN_REGION) - continue; - sz = DAMON_MIN_REGION; - } - damon_split_region_at(t, r, sz); - r = damon_next_region(r); - sz = damon_sz_region(r); - } - quota->charge_target_from = NULL; - quota->charge_addr_from = 0; - } + if (damos_skip_charged_region(t, &r, s)) + continue; if (!damos_valid_target(c, t, r, s)) continue; /* Apply the scheme */ + sz = damon_sz_region(r); if (c->ops.apply_scheme) { if (quota->esz && quota->charged_sz + sz > quota->esz) { -- 2.25.1