From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from dggsgout11.his.huawei.com (unknown [45.249.212.51]) (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 E2C0112D777; Tue, 23 Apr 2024 12:40:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.51 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713876055; cv=none; b=F52xvvSOYP7r7+Hmt4+lSRTgAU1VQFtOY5Ef5Vkrb86fvdqRz/l26zd2OPytXvZ9hj4KWaHoYnc281S/s6HGj7MFsNOFDR9BV3OweQwe5apNqw7HNjo/QhetXj1tey7uA3WCd/yU5QPRwNI6wr8Y6hCi3cHgeMCchAUbL9g79Hk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713876055; c=relaxed/simple; bh=t1U/InzqxiUqGU+e34imVaTcWHfcqLRThUU4nLPa18Q=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=gpNWE+EZxpXDuk8T25qMMuTMJijkhSaqMFDz9vx5Dj7chuWaKuTs+9jJ8JeEILxekH8qqPDeMirfbsVUxsLo9PLaMWv3JjHIwrOsDVfIoXvl/GjqOxXdg8wSlKdqzRa/Rct1DmkRsmw3jz7PMpWdzphu4lzUIQlZ4QjVEw+g9g0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com; spf=pass smtp.mailfrom=huaweicloud.com; arc=none smtp.client-ip=45.249.212.51 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.19.93.142]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4VP1tg4nx2z4f3kkd; Tue, 23 Apr 2024 20:40:43 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.112]) by mail.maildlp.com (Postfix) with ESMTP id 7BEA01A0179; Tue, 23 Apr 2024 20:40:48 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.124.27]) by APP1 (Coremail) with SMTP id cCh0CgA3VQ5OrCdm2gAAKw--.9734S3; Tue, 23 Apr 2024 20:40:48 +0800 (CST) From: Kemeng Shi To: tytso@mit.edu, adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org Cc: jack@suse.cz, ojaswin@linux.ibm.com, ritesh.list@gmail.com Subject: [PATCH v2 1/5] ext4: keep "prefetch_grp" and "nr" consistent Date: Tue, 23 Apr 2024 20:40:42 +0800 Message-Id: <20240423124046.974134-2-shikemeng@huaweicloud.com> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20240423124046.974134-1-shikemeng@huaweicloud.com> References: <20240423124046.974134-1-shikemeng@huaweicloud.com> Precedence: bulk X-Mailing-List: linux-ext4@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CM-TRANSID:cCh0CgA3VQ5OrCdm2gAAKw--.9734S3 X-Coremail-Antispam: 1UD129KBjvJXoW7Cr1Uur48urWfuFyfWw1rJFb_yoW8GrWUpF nak3y7Cr4rXr1UAayUG3Z0gw18Kw40gw12qFyIkryqq347ZryfJrsrtr4ruFWUZF47AFy3 uFnIy3W8WF1UGa7anT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUvCb4IE77IF4wAFF20E14v26r4j6ryUM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI8067AKxVWUGw A2048vs2IY020Ec7CjxVAFwI0_JFI_Gr1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxS w2x7M28EF7xvwVC0I7IYx2IY67AKxVW7JVWDJwA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxV W8Jr0_Cr1UM28EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I8E87Iv6xkF7I0E14v2 6rxl6s0DM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40Ex7xfMc Ij6xIIjxv20xvE14v26r1j6r18McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x0Yz7v_ Jr0_Gr1lF7xvr2IYc2Ij64vIr41l42xK82IYc2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr 0_Gr1lx2IqxVAqx4xG67AKxVWUJVWUGwC20s026x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY 17CE14v26r126r1DMIIYrxkI7VAKI48JMIIF0xvE2Ix0cI8IcVAFwI0_Jr0_JF4lIxAIcV C0I7IYx2IY6xkF7I0E14v26r4j6F4UMIIF0xvE42xK8VAvwI8IcIk0rVWUJVWUCwCI42IY 6I8E87Iv67AKxVW8JVWxJwCI42IY6I8E87Iv6xkF7I0E14v26r4UJVWxJrUvcSsGvfC2Kf nxnUUI43ZEXa7IU1X_-DUUUUU== X-CM-SenderInfo: 5vklyvpphqwq5kxd4v5lfo033gof0z/ Keep "prefetch_grp" and "nr" consistent to avoid to call ext4_mb_prefetch_fini with non-prefetched groups. When we step into next criteria, "prefetch_grp" is set to prefetch start of new criteria while "nr" is number of the prefetched group in previous criteria. If previous criteria and next criteria are both inexpensive (< CR_GOAL_LEN_SLOW) and prefetch_ios reachs sbi->s_mb_prefetch_limit in previous criteria, "prefetch_grp" and "nr" will be inconsistent and may introduce unexpected cost to do ext4_mb_init_group for non-prefetched groups. Reset "nr" to 0 when we reset "prefetch_grp" to goal group to keep them consistent. Signed-off-by: Kemeng Shi Reviewed-by: Ojaswin Mujoo Reviewed-by: Jan Kara --- fs/ext4/mballoc.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 12b3f196010b..a61fc52956b2 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -2856,6 +2856,7 @@ ext4_mb_regular_allocator(struct ext4_allocation_context *ac) group = ac->ac_g_ex.fe_group; ac->ac_groups_linear_remaining = sbi->s_mb_max_linear_groups; prefetch_grp = group; + nr = 0; for (i = 0, new_cr = cr; i < ngroups; i++, ext4_mb_choose_next_group(ac, &new_cr, &group, ngroups)) { -- 2.30.0