From nobody Tue Oct 7 07:06:11 2025 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) (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 D89E6248F5C; Mon, 14 Jul 2025 13:18:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.187 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752499116; cv=none; b=kY93+OkIu8+sdBYGFOexyzF9INGpmaHdeIJWJ3FY2V2H5MgP21HCQF08hX6NsWigxb9FZ8SyPWnh4e6ObqxZFt6apHw9EKHVcQ8BdRrX4w6DUB30U6ov1YTiOu2IhLIHZ2d+6oucX97vVFMe79G+HGQ2DxzlB7wZ6akuV42O5ew= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752499116; c=relaxed/simple; bh=s4gNMvY9cZOwDGjkUhM/jI1sppzTPno8BNjqtEuLb5w=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=AAx2CKul2LSMeWgZzSaH0DtqXDaPttndbqCXBFV0pg/eHsucrFEcnNFGk7dZy2Ms1LDxF/qWGSNZL6uZHV8oJzop1LSLAq8now3uhaeFCQm8D3tLIouDTzWXuhVOG0CvPZk9gMi9Rg8BVbcAqQOjpNxZMsW5mBC4biFgJs72VIE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=45.249.212.187 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.19.163.174]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4bgjVm6SVXz13Mnb; Mon, 14 Jul 2025 21:15:44 +0800 (CST) Received: from dggpemf500013.china.huawei.com (unknown [7.185.36.188]) by mail.maildlp.com (Postfix) with ESMTPS id 69D6014011A; Mon, 14 Jul 2025 21:18:30 +0800 (CST) Received: from huawei.com (10.175.112.188) by dggpemf500013.china.huawei.com (7.185.36.188) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Mon, 14 Jul 2025 21:18:29 +0800 From: Baokun Li To: CC: , , , , , , , , , Subject: [PATCH v3 02/17] ext4: separate stream goal hits from s_bal_goals for better tracking Date: Mon, 14 Jul 2025 21:03:12 +0800 Message-ID: <20250714130327.1830534-3-libaokun1@huawei.com> X-Mailer: git-send-email 2.46.1 In-Reply-To: <20250714130327.1830534-1-libaokun1@huawei.com> References: <20250714130327.1830534-1-libaokun1@huawei.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-ClientProxiedBy: kwepems500001.china.huawei.com (7.221.188.70) To dggpemf500013.china.huawei.com (7.185.36.188) Content-Type: text/plain; charset="utf-8" In ext4_mb_regular_allocator(), after the call to ext4_mb_find_by_goal() fails to achieve the inode goal, allocation continues with the stream allocation global goal. Currently, hits for both are combined in sbi->s_bal_goals, hindering accurate optimization. This commit separates global goal hits into sbi->s_bal_stream_goals. Since stream allocation doesn't use ac->ac_g_ex.fe_start, set fe_start to -1. This prevents stream allocations from being counted in s_bal_goals. Also clear EXT4_MB_HINT_TRY_GOAL to avoid calling ext4_mb_find_by_goal again. After adding `stream_goal_hits`, `/proc/fs/ext4/sdx/mb_stats` will show: mballoc: reqs: 840347 success: 750992 groups_scanned: 1230506 cr_p2_aligned_stats: hits: 21531 groups_considered: 411664 extents_scanned: 21531 useless_loops: 0 bad_suggestions: 6 cr_goal_fast_stats: hits: 111222 groups_considered: 1806728 extents_scanned: 467908 useless_loops: 0 bad_suggestions: 13 cr_best_avail_stats: hits: 36267 groups_considered: 1817631 extents_scanned: 156143 useless_loops: 0 bad_suggestions: 204 cr_goal_slow_stats: hits: 106396 groups_considered: 5671710 extents_scanned: 22540056 useless_loops: 123747 cr_any_free_stats: hits: 138071 groups_considered: 724692 extents_scanned: 23615593 useless_loops: 585 extents_scanned: 46804261 goal_hits: 1307 stream_goal_hits: 236317 len_goal_hits: 155549 2^n_hits: 21531 breaks: 225096 lost: 35062 buddies_generated: 40/40 buddies_time_used: 48004 preallocated: 5962467 discarded: 4847560 Signed-off-by: Baokun Li --- fs/ext4/ext4.h | 1 + fs/ext4/mballoc.c | 11 +++++++++-- 2 files changed, 10 insertions(+), 2 deletions(-) diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 9df74123e7e6..8750ace12935 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -1646,6 +1646,7 @@ struct ext4_sb_info { atomic_t s_bal_cX_ex_scanned[EXT4_MB_NUM_CRS]; /* total extents scanned */ atomic_t s_bal_groups_scanned; /* number of groups scanned */ atomic_t s_bal_goals; /* goal hits */ + atomic_t s_bal_stream_goals; /* stream allocation global goal hits */ atomic_t s_bal_len_goals; /* len goal hits */ atomic_t s_bal_breaks; /* too long searches */ atomic_t s_bal_2orders; /* 2^order hits */ diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 336d65c4f6a2..f56ac477c464 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -2849,8 +2849,9 @@ ext4_mb_regular_allocator(struct ext4_allocation_cont= ext *ac) /* TBD: may be hot point */ spin_lock(&sbi->s_md_lock); ac->ac_g_ex.fe_group =3D sbi->s_mb_last_group; - ac->ac_g_ex.fe_start =3D sbi->s_mb_last_start; spin_unlock(&sbi->s_md_lock); + ac->ac_g_ex.fe_start =3D -1; + ac->ac_flags &=3D ~EXT4_MB_HINT_TRY_GOAL; } =20 /* @@ -3000,8 +3001,12 @@ ext4_mb_regular_allocator(struct ext4_allocation_con= text *ac) } } =20 - if (sbi->s_mb_stats && ac->ac_status =3D=3D AC_STATUS_FOUND) + if (sbi->s_mb_stats && ac->ac_status =3D=3D AC_STATUS_FOUND) { atomic64_inc(&sbi->s_bal_cX_hits[ac->ac_criteria]); + if (ac->ac_flags & EXT4_MB_STREAM_ALLOC && + ac->ac_b_ex.fe_group =3D=3D ac->ac_g_ex.fe_group) + atomic_inc(&sbi->s_bal_stream_goals); + } out: if (!err && ac->ac_status !=3D AC_STATUS_FOUND && first_err) err =3D first_err; @@ -3194,6 +3199,8 @@ int ext4_seq_mb_stats_show(struct seq_file *seq, void= *offset) seq_printf(seq, "\textents_scanned: %u\n", atomic_read(&sbi->s_bal_ex_scanned)); seq_printf(seq, "\t\tgoal_hits: %u\n", atomic_read(&sbi->s_bal_goals)); + seq_printf(seq, "\t\tstream_goal_hits: %u\n", + atomic_read(&sbi->s_bal_stream_goals)); seq_printf(seq, "\t\tlen_goal_hits: %u\n", atomic_read(&sbi->s_bal_len_goals)); seq_printf(seq, "\t\t2^n_hits: %u\n", atomic_read(&sbi->s_bal_2orders)); --=20 2.46.1