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 7DAECCD4850 for ; Fri, 22 Sep 2023 18:45:03 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qjl8K-0002ru-04; Fri, 22 Sep 2023 14:44:08 -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 1qjl8I-0002rZ-HE for qemu-devel@nongnu.org; Fri, 22 Sep 2023 14:44:06 -0400 Received: from smtp-out2.suse.de ([2001:67c:2178:6::1d]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1qjl8H-0004lC-19 for qemu-devel@nongnu.org; Fri, 22 Sep 2023 14:44:06 -0400 Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 04F8D1FE06; Fri, 22 Sep 2023 18:44:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1695408243; h=from:from:reply-to: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=CLl+qkTthLCjQ/mv06T/Vy7hmkZaE6TlkYWzn0rw1Qs=; b=gwKHNEO/KcghGTFe3gqaBWTQsHHQYJ93ISnkFXv5o6xvy/EGR+S92URdLfMfw7Bo2p8dOE XEjNuLUneAchhgDNIApt4cogSFoFu3tXJ8dHPkiuzxgkzWDJ64QvfFe5mIhan0uNI5RSND j/X2eEsGCOZa2SJF+HDOc7pOC/jAx1o= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1695408243; h=from:from:reply-to: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=CLl+qkTthLCjQ/mv06T/Vy7hmkZaE6TlkYWzn0rw1Qs=; b=W5acMSnYRtzMCxhUEtKGUFdaOzBXI17STOefRgkz6I+D4J6LWl2DCcxTJBfKagSsuRYn0y KmY2c6r6zEX2aTDQ== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 8C30713478; Fri, 22 Sep 2023 18:44:02 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id i8LtFXLgDWWCdwAAMHmgww (envelope-from ); Fri, 22 Sep 2023 18:44:02 +0000 From: Fabiano Rosas To: Elena Ufimtseva , quintela@redhat.com, peterx@redhat.com, leobras@redhat.com Cc: elena.ufimtseva@oracle.com, qemu-devel@nongnu.org Subject: Re: [PATCH 4/4] multifd: reset next_packet_len after sending pages In-Reply-To: <20230922065625.21848-5-elena.ufimtseva@oracle.com> References: <20230922065625.21848-1-elena.ufimtseva@oracle.com> <20230922065625.21848-5-elena.ufimtseva@oracle.com> Date: Fri, 22 Sep 2023 15:44:00 -0300 Message-ID: <87y1gykpzj.fsf@suse.de> MIME-Version: 1.0 Content-Type: text/plain Received-SPF: pass client-ip=2001:67c:2178:6::1d; envelope-from=farosas@suse.de; helo=smtp-out2.suse.de X-Spam_score_int: -43 X-Spam_score: -4.4 X-Spam_bar: ---- X-Spam_report: (-4.4 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_MED=-2.3, 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 Elena Ufimtseva writes: > Sometimes multifd sends just sync packet with no pages > (normal_num is 0). In this case the old value is being > preserved and being accounted for while only packet_len > is being transferred. > Reset it to 0 after sending and accounting for. > Usually you'd finish your commit message here with your Signed off tag and the comments below would be included after the following --- sign. That way we can merge this patch without bring the unrelated discussion along. > TODO: Fix the same packet ids in the stream. > with this patch, there is still an issue with the duplicated > packets ids being sent (with different number of pages/flags). > See in below multifd_send trace (before this change): > multifd_send 394.774 pid=55477 id=0x1 packet_num=0x6f0 normal=0x57 flags=0x1 next_packet_size=0x57000 > multifd_send 181.244 pid=55477 id=0x1 packet_num=0x6f0 normal=0x0 flags=0x0 next_packet_size=0x57000 > > With this commit there are still duplicated packets, but since no pages > are being sent with sync flag set, next_packet_size is 0: > multifd_send 27.814 pid=18602 id=0x1 packet_num=0x574 normal=0x7b flags=0x1 next_packet_size=0x7b000 > multifd_send 136054.792 pid=18602 id=0x1 packet_num=0x574 normal=0x0 flags=0x0 next_packet_size=0x0 > If there is a suggestion how to fix this properly, I will be > glad to use it. What is going on here? Is it that we're incrementing the multifd_send_state->packet_num under different locks? Because p->mutex is per-channel? You could try turning that into an atomic operation instead.