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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 93E83C28B2E for ; Mon, 10 Mar 2025 10:56:20 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1trane-0000U1-0F; Mon, 10 Mar 2025 06:55:58 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tranc-0000Td-T6 for qemu-devel@nongnu.org; Mon, 10 Mar 2025 06:55:56 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tranb-0005zv-B3 for qemu-devel@nongnu.org; Mon, 10 Mar 2025 06:55:56 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1741604154; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=otnCTJvwM/oZxaxCGGiHqyfzZUUoURQ5Etc1ZfTzmaI=; b=Y/22zSMbq+yLVXV4a1UB3xR8W75ctnBFCfWDTCUZdq4zsfhy22+qI+B6dhLhUwJHFdyfRC pe+0daLZCK16fEdtlBtl7LK95OFGtVKZ1gtlx/jSOk+lxEjd79Fh28rl4NmIpp/fJi0kAJ 3cWSAsvWFmLPePblrGpEmbV3bKiqN9s= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-219-skQAGwrpPqK7RqvqAYpPCg-1; Mon, 10 Mar 2025 06:55:53 -0400 X-MC-Unique: skQAGwrpPqK7RqvqAYpPCg-1 X-Mimecast-MFC-AGG-ID: skQAGwrpPqK7RqvqAYpPCg_1741604152 Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 1DC92195609E; Mon, 10 Mar 2025 10:55:52 +0000 (UTC) Received: from localhost (unknown [10.2.16.19]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 42E043000197; Mon, 10 Mar 2025 10:55:50 +0000 (UTC) Date: Mon, 10 Mar 2025 18:55:48 +0800 From: Stefan Hajnoczi To: Kevin Wolf Cc: qemu-block@nongnu.org, pbonzini@redhat.com, afaria@redhat.com, hreitz@redhat.com, qemu-devel@nongnu.org Subject: Re: [PATCH 0/5] block: Improve writethrough performance Message-ID: <20250310105548.GF359802@fedora> References: <20250307221634.71951-1-kwolf@redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="ypp4Iwa9KBVaB3C8" Content-Disposition: inline In-Reply-To: <20250307221634.71951-1-kwolf@redhat.com> X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 Received-SPF: pass client-ip=170.10.129.124; envelope-from=stefanha@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org --ypp4Iwa9KBVaB3C8 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Mar 07, 2025 at 11:16:29PM +0100, Kevin Wolf wrote: > Write requests in writethrough mode mean that QEMU sends a separate > flush request (i.e. fdatasync) after each completed write request. > This is unnecessary overhead when we can just pass a flag for the write > request that gives us the desired FUA semantics. >=20 > Unfortunately, this made a problem in the adaptive polling algorithm > apparent that would result in a performance regression in some cases > with FUA support in file-posix. Therefore, adaptive polling is changed > in this series, too, to avoid the regression. Looks good! Stefan >=20 > Kevin Wolf (5): > file-posix: Support FUA writes > block/io: Ignore FUA with cache.no-flush=3Don > aio: Create AioPolledEvent > aio-posix: Factor out adjust_polling_time() > aio-posix: Separate AioPolledEvent per AioHandler >=20 > include/block/aio.h | 5 ++- > include/block/raw-aio.h | 8 +++- > util/aio-posix.h | 1 + > block/file-posix.c | 26 ++++++++---- > block/io.c | 4 ++ > block/io_uring.c | 13 +++--- > block/linux-aio.c | 24 +++++++++-- > util/aio-posix.c | 94 ++++++++++++++++++++++++++--------------- > util/async.c | 1 - > meson.build | 4 ++ > 10 files changed, 125 insertions(+), 55 deletions(-) >=20 > --=20 > 2.48.1 >=20 --ypp4Iwa9KBVaB3C8 Content-Type: application/pgp-signature; name=signature.asc -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEhpWov9P5fNqsNXdanKSrs4Grc8gFAmfOxTQACgkQnKSrs4Gr c8hD8AgArcDGM7jSULDV26rmMUbPt1M/IBXynkIW7fWfJ3BEzEcVhN01/+xG2KbN 9Y+GANldK91Qso9Jbqmab6diZHHBIDCh4II/fmDW9mMvoQmn8I/D0qGw+xOv9PYR UrWz656a0f/PPS3c/mTedXkpuLjaGyoo0Kln/WlE9l+PEH3hGag9yBjQdQicwKnZ pvoLm6HKDEbtIZQ4wmwyk/zRtP8dVPoQGKnnj5Qblh1q0G42ZXUBXJDvLn8poxj5 9iEouSMK4SiLBESSHeopeUZ/OfO8uAgSrc7oIZPEAYQR1aMIfkwYgivrW+zIND2H OJg7s5v04ujB9BowWS6nYN+vewoNlQ== =ME7N -----END PGP SIGNATURE----- --ypp4Iwa9KBVaB3C8--