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 CD7BAC761A6 for ; Tue, 4 Apr 2023 16:04:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235496AbjDDQEM (ORCPT ); Tue, 4 Apr 2023 12:04:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40046 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235241AbjDDQEL (ORCPT ); Tue, 4 Apr 2023 12:04:11 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:3::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 55DE340E5 for ; Tue, 4 Apr 2023 09:04:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=AIQoaJjLGvMKIM9H6StwFqIBqyuniKMBTqapbhz/gN0=; b=C5QndD65ObgzxSp4zngLt0Le02 M4pcmQkV5RoeW4zf15Tylbc52Bh+F8gRtqAJR4Axx0t3lgLGtZZ0i54vpqscF159sl/cPov8C8vRw OKj2ct8Gm5NdQJp3IOM0B4kkk5Y+fg3KoNaEQfx8evn2UkLsvhjqxCbhQgIWzP21C6hccqdgl5tny lJRxoHMNe1TB959xCi0rmepfXNSxWlox4PDeE1jfbQrfU3vacFQrBnZuCXLzuL41EeLdju8DJMawx y+0mR4XIQ5lemf90bWDc1Zv5KHArFeO0fGYuLxz9plkzegl4F8oy+dgIOowloK1UeNn811y0bXZ18 lTumzf6g==; Received: from hch by bombadil.infradead.org with local (Exim 4.96 #2 (Red Hat Linux)) id 1pjj8e-0028oS-02; Tue, 04 Apr 2023 16:04:04 +0000 Date: Tue, 4 Apr 2023 09:04:03 -0700 From: Christoph Hellwig To: Linux regressions mailing list Cc: Sergei Trofimovich , Christoph Hellwig , Josef Bacik , Christopher Price , anand.jain@oracle.com, boris@bur.io, clm@fb.com, dsterba@suse.com, linux-btrfs@vger.kernel.org Subject: Re: [6.2 regression][bisected]discard storm on idle since v6.1-rc8-59-g63a7cb130718 discard=async Message-ID: References: <20230323222606.20d10de2@nz> <20d85dc4-b6c2-dac1-fdc6-94e44b43692a@leemhuis.info> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20d85dc4-b6c2-dac1-fdc6-94e44b43692a@leemhuis.info> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On Tue, Apr 04, 2023 at 12:49:40PM +0200, Linux regression tracking (Thorsten Leemhuis) wrote: > >> And that jut NVMe, the still shipping SATA SSDs are another different > >> story. Not helped by the fact that we don't even support ranged > >> discards for them in Linux. > > Thx for your comments Christoph. Quick question, just to be sure I > understand things properly: > > I assume on some of those problematic devices these discard storms will > lead to a performance regression? Probably. > I also heard people saying these discard storms might reduce the life > time of some devices - is that true? Also very much possible. There are various SSDs that treat a discard as a write zeroes and always return zeroes from all discarded blocks. If the discards are smaller than or not aligned to the internal erase (super)blocks, this will actually cause additional writes. > If the answer to at least one of these is "yes" I'd say we it might be > best to revert 63a7cb130718 for now. I don't think enabling it is a very a smart idea for most consumer devices.