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 X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2809CC43603 for ; Mon, 16 Dec 2019 02:37:08 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id F13942465E for ; Mon, 16 Dec 2019 02:37:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F13942465E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:45538 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iggFv-00062m-3S for qemu-devel@archiver.kernel.org; Sun, 15 Dec 2019 21:37:07 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:36721) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iggF9-00055A-6L for qemu-devel@nongnu.org; Sun, 15 Dec 2019 21:36:20 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iggF8-0005IK-65 for qemu-devel@nongnu.org; Sun, 15 Dec 2019 21:36:19 -0500 Received: from mga05.intel.com ([192.55.52.43]:61023) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iggF7-0005GM-Sz for qemu-devel@nongnu.org; Sun, 15 Dec 2019 21:36:18 -0500 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 15 Dec 2019 18:36:16 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.69,320,1571727600"; d="scan'208";a="204965226" Received: from richard.sh.intel.com (HELO localhost) ([10.239.159.54]) by orsmga007.jf.intel.com with ESMTP; 15 Dec 2019 18:36:15 -0800 Date: Mon, 16 Dec 2019 10:36:13 +0800 From: Wei Yang To: Wei Yang Subject: Re: [PATCH v2 0/6] migration/multifd: a new mechanism for send thread sync Message-ID: <20191216023613.GC21865@richard> References: <20191026004520.5515-1-richardw.yang@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191026004520.5515-1-richardw.yang@linux.intel.com> User-Agent: Mutt/1.9.4 (2018-02-28) X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 192.55.52.43 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Wei Yang Cc: qemu-devel@nongnu.org, dgilbert@redhat.com, quintela@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Ping for comment. On Sat, Oct 26, 2019 at 08:45:14AM +0800, Wei Yang wrote: >Current send thread could work while the sync mechanism has some problem: > > * has spuriously wakeup > * number of channels_ready will *overflow* the number of real channels > >The reason is: > > * if MULTIFD_FLAG_SYNC is set in the middle of send thread running, there > is one more spurious wakeup > * if MULTIFD_FLAG_SYNC is set when send thread is not running, there is one > more channels_ready be triggered > >To solve this situation, one new mechanism is introduced to synchronize send >threads. The idea is simple, a new field *sync* is introduced to indicate a >synchronization is required. > >--- >v2: rebase on latest code > >Wei Yang (6): > migration/multifd: move Params update and pages cleanup into > multifd_send_fill_packet() > migration/multifd: notify channels_ready when send thread starts > migration/multifd: use sync field to synchronize send threads > migration/multifd: used must not be 0 for a pending job > migration/multifd: use boolean for pending_job is enough > migration/multifd: there is no spurious wakeup now > > migration/ram.c | 74 +++++++++++++++++++++++++++++++------------------ > 1 file changed, 47 insertions(+), 27 deletions(-) > >-- >2.17.1 -- Wei Yang Help you, Help me