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 B6BE0C4332F for ; Mon, 13 Nov 2023 10:09:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233469AbjKMKJl (ORCPT ); Mon, 13 Nov 2023 05:09:41 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47918 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229988AbjKMKJj (ORCPT ); Mon, 13 Nov 2023 05:09:39 -0500 Received: from truschnigg.info (truschnigg.info [89.163.150.210]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B9F4810C2 for ; Mon, 13 Nov 2023 02:09:35 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=truschnigg.info; s=m22; t=1699870174; bh=Q42oWjUoIWyENQdwAqemkYJ5SIL8YslqTTx4TXyzfrQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Y3IV1J0A+Hs8qaGQwCsvGN3qTUw60NDTs/3I5LRxP/RlCpALR6LAQHdAWT2ho3Dzr AlBU3RidR7cpCNdtQm8UzZLXdNnhuIGj9xz/FanR2q19+hocyk1s+l9XD+x62gQPPP amRbBN4sflnxr3WttD6m8LEJ3tLzp9z/YH7LGyNiuDFSbIxLjcRVewWr2ZytVewI/A 2HAWRPUeEwDx/uUC0MnaM8sL7N9TNTq88ysLJ7YCtRO2sLm7WMmAP7G/WdWH+izEgo fRNIsnPV3RsPAiwlxy4kRkE21sFiz2T0x0vDM9/iuce81pj8haqxReTv24yPJPDvlL ODYgbZbAcWViA== Received: from vault.lan (unknown [IPv6:2a02:1748:fafe:cf3f:1eb7:2cff:fe02:8261]) by truschnigg.info (Postfix) with ESMTPSA id F176E2035C; Mon, 13 Nov 2023 10:09:33 +0000 (UTC) Date: Mon, 13 Nov 2023 11:09:32 +0100 From: Johannes Truschnigg To: eyal@eyal.emu.id.au Cc: linux-raid@vger.kernel.org Subject: Re: extremely slow writes to array [now not degraded] Message-ID: References: <1d0fb40a-1908-4b5e-9856-a5b79eafdc9c@eyal.emu.id.au> <182d07c8-a76e-430d-90e8-6df8c1f1c54d@eyal.emu.id.au> <60e4892e-f6b3-4f0a-956d-09555d8ee147@eyal.emu.id.au> <09d9848d-8ef4-488c-8719-7ad451c9e36b@eyal.emu.id.au> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="g1hl2ZCKRa1WuKqq" Content-Disposition: inline In-Reply-To: <09d9848d-8ef4-488c-8719-7ad451c9e36b@eyal.emu.id.au> Precedence: bulk List-ID: X-Mailing-List: linux-raid@vger.kernel.org --g1hl2ZCKRa1WuKqq Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Nov 13, 2023 at 08:58:55PM +1100, eyal@eyal.emu.id.au wrote: > [trimmed] > > > [0]: https://bugzilla.kernel.org/show_bug.cgi?id=3D217965 >=20 > Reading this bugzilla, an extra info bit. This has not changed for years = (I have daily records). >=20 > $ mount|grep data1 > /dev/md127 on /data1 type ext4 (rw,noatime,stripe=3D640) Yeah, afaiui, one of the theories in the bug suggests that a recently introduced block allocation improvement made matters worse for any kind of stride/stripe setting <> 0. So if you dial your kernel version back to befo= re that was made (6.4 seems to be unaffacted, iirc), you will probably regain = the performance loss you observe and reported here on list. FWIW, I briefly played around with an artificial dataset on tmpfs-backed lo= op devices configured in RAID5 where I was (re)setting the superblock-configur= ed stride-setting, and did not lose any data by toggling it between 0 and (256 in my case) multiple times. So I would assume that = to be a safe operation in principle ;) --=20 with best regards: - Johannes Truschnigg ( johannes@truschnigg.info ) www: https://johannes.truschnigg.info/ phone: +436502133337 xmpp: johannes@truschnigg.info --g1hl2ZCKRa1WuKqq Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCgAdFiEEGu9IhkI+7/aKLUWF95W3jMsYfLUFAmVR9dkACgkQ95W3jMsY fLUTyRAAuFk4O4exRw09kQh0z11LMUsUhhGz/Diyp0NdOM4DsLOmkHQ7kv/vZ+03 AZHVssq2o4vO8e5CLMU0AnPyQ9hd/Nsv+V0YmWuFIBKbfDxxbTAOLNhYIx/V9ND9 nwqVjPoIBlGa9ip/ss2sGcofQHAuhzYF7zkgLGRC1VI0xgZXXevqkO5HwLAaOeFz gH/SWwAovGkmkZsdeWCuFuOshZY+tU2vysiuOdWcirYmNwsmVPwaHnoIuWjDCRoY Y22X0Ik79sj6dlJ76mr6d9wdr4kIw1bdVdv53+LhQVoPjWlGGAgmUdY++JvF59WY xauIVFZ4A6D029FRaLq7X5d5WyJYzDkdfhuoNqnANC3MW1RajpeTbich9KaYNenN krZ5fTzmVP0dzpFMJ2yKkDjxBrIULFOpySGupt6twu6r8MM4vw0RxrlxT8snrTlt EqDV6VaamvgrWaDAlhX60tJpga39utqjKahtx4frx3ZarLDmlgf4TUQeCjnmHzhI 68Qjui0lD1RGXuQyzLqKSr0QEuJLHhJh5XJRmectE3HRdfHfxBxtmhxg/ZJAGPAO jKtClqdwgmZHscdkEbw5LT6O5hmYU4NKLlDw38L/ZtJ3ASnDlvk9/F4XNhFF8y/L kkOLMdf4Mpaizgh8dFxhATjWF6ZIxC8gSGA9CCMF8s3oDxXyHuc= =rnUA -----END PGP SIGNATURE----- --g1hl2ZCKRa1WuKqq--