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 4014E243964 for ; Wed, 27 Aug 2025 17:07:17 +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=1756314438; cv=none; b=QO9q7JmfMP/ZYoLEO4LjPTo2KmYYeUcRc5HeaH7+kPOmmdyoll2F7Q191elFIF16d9X7exbo0lIoDVNpYmM+cayQtVV5fFOCff3vzJR+EMOymv5wgcvBdXVJ/s0bwi9krHaWPg7p5/zrlPJIQ3tbL2FJ2kRa2+ErtEhKorSAfVY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756314438; c=relaxed/simple; bh=5fjP4Ppe8zZ6g65SdrCMmNMCph9uNSl2nljC6mgEVIg=; h=From:To:Subject:Date:Message-ID:In-Reply-To:References: Content-Type:MIME-Version; b=SQ1i7CrG0qotG/yGOMjxH9t0LFT2jNiSVRAfhP/lpcZvVpoSm/MUn6FllODJFnp9v2M1CimCVpAnrnggyStRRnXC5gKiVv+P/Ij4EmERomhhWRmAf3U7Oji8u5LS30fgHfCKFnRFGuTa8yJ5LTeT2qYmeF/WPkrDnYL2tvB+9CI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ABxfTmBL; 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="ABxfTmBL" Received: by smtp.kernel.org (Postfix) with ESMTPS id D093AC4CEEB for ; Wed, 27 Aug 2025 17:07:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1756314437; bh=5fjP4Ppe8zZ6g65SdrCMmNMCph9uNSl2nljC6mgEVIg=; h=From:To:Subject:Date:In-Reply-To:References:From; b=ABxfTmBLtZTPqbvmIaI9hqDrLKQCA3Kgnhwfr85Wdw6SELHZvanDO8dxgkUsLXpSu 7GQOZm6bJ5nAYFdfn+MPehW6yRPfdLWr48oFfItwVULP5XIudmfS5EXmK/sAcqPMld mnBh/7TN7b65ptfnu98Cd9s0PvJoJLt0FMZD/jjSACN9a5YMCpA4ctddtvsA+Y4eAV 4yNPIyhg4TSmR4X+wcjBCWDsPyFpP9eLrbBc+3wxKqVlIMgVjRztwsrZuukpkSSBUF 5wngZOSCWPUBpZetojlY1AiWehORe7RYsbb6hWEftgRx327q80RboWvQrLmAY38tZz s8cYC4a1iVIaQ== Received: by aws-us-west-2-korg-bugzilla-1.web.codeaurora.org (Postfix, from userid 48) id CA276C53BBF; Wed, 27 Aug 2025 17:07:17 +0000 (UTC) From: bugzilla-daemon@kernel.org To: linux-ext4@vger.kernel.org Subject: [Bug 217965] ext4(?) regression since 6.5.0 on sata hdd Date: Wed, 27 Aug 2025 17:07:17 +0000 X-Bugzilla-Reason: None X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: AssignedTo fs_ext4@kernel-bugs.osdl.org X-Bugzilla-Product: File System X-Bugzilla-Component: ext4 X-Bugzilla-Version: 2.5 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: ojaswin.mujoo@ibm.com X-Bugzilla-Status: NEW X-Bugzilla-Resolution: X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: fs_ext4@kernel-bugs.osdl.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugzilla.kernel.org/ Auto-Submitted: auto-generated Precedence: bulk X-Mailing-List: linux-ext4@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 https://bugzilla.kernel.org/show_bug.cgi?id=3D217965 --- Comment #73 from Ojaswin Mujoo (ojaswin.mujoo@ibm.com) --- Hi Mingyu, Thanks for looking into this and sharing the reproducer. You are correct in= the analysis that we were getting stuck trying to check the same block group for aligned blocks, due to the fact that the fragment lists always returned the same group.=20 However, about this: > The author changed the fragment order RB tree into list for better > performance. > However, the function 'ext4_mb_find_good_group_avg_frag_lists' will alway= s=20 > returns the same group every time, The change from rbtree to list was not done in the patchset you listed but rather here: https://lore.kernel.org/all/20220908092136.11770-5-jack@suse.cz/ which got merged in v6.0 kernel hence I think the behavior of fragment lists returning the same block group was there even before my patchset (the one y= ou listed) However I remember people had mentioned that they started to see it after v6.5.=20 Its been sometime since I looked into this but I remember I had concluded t= hat since my patchset added new allocation criteria which made the allocator tr= im the request to more aggressively look for BGs in the free fragment lists, we just made this bug more easier to hit. I tried the replicator however I was unable to get to the high CPU util, but since you already have the setup, can you check if you are able to hit this issue in v6.4 vs v6.5. Thanks again, Ojaswin --=20 You may reply to this email to add a comment. You are receiving this mail because: You are watching the assignee of the bug.=