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 C0212C36010 for ; Thu, 27 Mar 2025 15:36:22 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1txpGi-0002g8-DK; Thu, 27 Mar 2025 11:35:44 -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 1txpGh-0002fw-BZ for qemu-devel@nongnu.org; Thu, 27 Mar 2025 11:35:43 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1txpGf-00062R-QT for qemu-devel@nongnu.org; Thu, 27 Mar 2025 11:35:43 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1743089740; 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=PVJbi9jSUcmExBus59v72mNs9lrHVlaais4lj3pr/sg=; b=c2SFZBEg8g/+0B19vT/TkTNafpfx0/RkKjtuTgxBGrX6VjJcgg4uwVRYBcXFqKjPphq357 4J3CGN9lAjxhaSPzLtQDqtCeZlApSdUR7LmsALknNeCQltY0mVFJbUqoKr+QqRjKtE6vnN nTVQ50Fa4dHN3DdvNPUg6SN6kjEOuhY= Received: from mx-prod-mc-01.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-532-i-BFy3mePFKQsgwpJI-t9w-1; Thu, 27 Mar 2025 11:35:38 -0400 X-MC-Unique: i-BFy3mePFKQsgwpJI-t9w-1 X-Mimecast-MFC-AGG-ID: i-BFy3mePFKQsgwpJI-t9w_1743089737 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (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-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 0DD8F196D2CF; Thu, 27 Mar 2025 15:35:36 +0000 (UTC) Received: from localhost (unknown [10.2.16.93]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 7EF2A1801751; Thu, 27 Mar 2025 15:35:35 +0000 (UTC) Date: Thu, 27 Mar 2025 11:35:34 -0400 From: Stefan Hajnoczi To: Hanna Czenczek Cc: qemu-block@nongnu.org, qemu-devel@nongnu.org, Kevin Wolf Subject: Re: [PATCH 12/15] fuse: Reduce max read size Message-ID: <20250327153534.GL37458@fedora> References: <20250325160529.117543-1-hreitz@redhat.com> <20250325160655.119407-11-hreitz@redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="Eb5t77td+hdI8FU+" Content-Disposition: inline In-Reply-To: <20250325160655.119407-11-hreitz@redhat.com> X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 Received-SPF: pass client-ip=170.10.133.124; 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_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 --Eb5t77td+hdI8FU+ Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Mar 25, 2025 at 05:06:52PM +0100, Hanna Czenczek wrote: > We are going to introduce parallel processing via coroutines, a maximum > read size of 64 MB may be problematic, allowing users of the export to > force us to allocate quite large amounts of memory with just a few > requests. >=20 > At least tone it down to 1 MB, which is still probably far more than > enough. (Larger requests are split automatically by the FUSE kernel > driver anyway.) >=20 > (Yes, we inadvertently already had parallel request processing due to > nested polling before. Better to fix this late than never.) >=20 > Signed-off-by: Hanna Czenczek > --- > block/export/fuse.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) Reviewed-by: Stefan Hajnoczi --Eb5t77td+hdI8FU+ Content-Type: application/pgp-signature; name=signature.asc -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEhpWov9P5fNqsNXdanKSrs4Grc8gFAmflcEYACgkQnKSrs4Gr c8jpqggAwKZ52QmR6nB9tHXruJXDWPKwxdU/OXRqWiKxVKztSKVvG1XAImL6Gn3h ZLqj3Skk8b2smfGM1vPJmpNBGWuZj3k5GHztaZxJtxZOsKPN5JwHxdfJsXK2LKMk bzWpABCEza3O4fV2D8J5EsB4R+c5dQCXUVbGo+C5a0zafH4liK4KJBjvWIVQeqKm u4fHnUd4qex2WCOS5SJ3peeV11ZtJhslKrBfNMNL3G9Qj0VbUgqpSHz5ii5dqedl s8YiDbOZyvS6RrqGZ9hP79lIOwNlQkIk0EJDNLk89/L7FieIl14JoeiNNSKIgV4A C/MUbtz1gNpJyfZ+s7liyN4X+5qUJQ== =HOPT -----END PGP SIGNATURE----- --Eb5t77td+hdI8FU+--