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=-3.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 6E5B2C04AB5 for ; Thu, 6 Jun 2019 08:49:07 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id F19AE20684 for ; Thu, 6 Jun 2019 08:49:06 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F19AE20684 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 ([127.0.0.1]:56638 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hYo54-0000Qi-3P for qemu-devel@archiver.kernel.org; Thu, 06 Jun 2019 04:49:06 -0400 Received: from eggs.gnu.org ([209.51.188.92]:55536) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hYnyg-0003m0-3h for qemu-devel@nongnu.org; Thu, 06 Jun 2019 04:42:33 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hYnsG-0003Tf-Vv for qemu-devel@nongnu.org; Thu, 06 Jun 2019 04:35:53 -0400 Received: from mga18.intel.com ([134.134.136.126]:52085) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hYnsG-0003SS-LW for qemu-devel@nongnu.org; Thu, 06 Jun 2019 04:35:52 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga106.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 06 Jun 2019 01:35:50 -0700 X-ExtLoop1: 1 Received: from richard.sh.intel.com (HELO localhost) ([10.239.159.54]) by orsmga002.jf.intel.com with ESMTP; 06 Jun 2019 01:35:49 -0700 From: Wei Yang To: qemu-devel@nongnu.org Date: Thu, 6 Jun 2019 16:34:55 +0800 Message-Id: <20190606083501.2087-1-richardw.yang@linux.intel.com> X-Mailer: git-send-email 2.19.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 134.134.136.126 Subject: [Qemu-devel] [PATCH 0/6] multifd: a new mechanism for send thread sync X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Wei Yang , dgilbert@redhat.com, quintela@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" 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. Wei Yang (6): migration/multifd: move MultiFDSendParams handling 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 | 62 +++++++++++++++++++++++++++++++------------------ 1 file changed, 39 insertions(+), 23 deletions(-) -- 2.19.1