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=-6.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS 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 181B5C33CB1 for ; Tue, 14 Jan 2020 13:06:13 +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 D5FC52467C for ; Tue, 14 Jan 2020 13:06:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="emyApK6a" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D5FC52467C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:39036 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1irLtb-0007h3-DQ for qemu-devel@archiver.kernel.org; Tue, 14 Jan 2020 08:06:11 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:41187) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1irLj3-00033t-Vs for qemu-devel@nongnu.org; Tue, 14 Jan 2020 07:55:23 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1irLj0-0001nb-59 for qemu-devel@nongnu.org; Tue, 14 Jan 2020 07:55:17 -0500 Received: from us-smtp-1.mimecast.com ([207.211.31.81]:35343 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1irLj0-0001n7-0A for qemu-devel@nongnu.org; Tue, 14 Jan 2020 07:55:14 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1579006513; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=a+D0Jhjaw7oJJMu/pHqSxLnV5MGTcL/XHY7MlyuPryQ=; b=emyApK6axfJWsHQKDHWQ7fcEZ6pc1XpFvvEuXPM5f3iGbZDLtqj5Fh4WbkyWsj5AZ8zPxA g+S1GNn9Z3CYhJAlrKVXn1oorPkfkbkArrKnFffak1psIiGBMpSroe+5Cn/EnVczw9xqmc ssGUzTTokniUKgNi/hLMg28oUs1v0bw= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-371-cATNDCvfOGqZhOhtdNQrfw-1; Tue, 14 Jan 2020 07:55:12 -0500 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id E05AA107ACC4; Tue, 14 Jan 2020 12:55:09 +0000 (UTC) Received: from secure.mitica (ovpn-116-207.ams2.redhat.com [10.36.116.207]) by smtp.corp.redhat.com (Postfix) with ESMTP id 441175DA76; Tue, 14 Jan 2020 12:55:03 +0000 (UTC) From: Juan Quintela To: qemu-devel@nongnu.org Subject: [PULL 15/30] migration/ram: Yield periodically to the main loop Date: Tue, 14 Jan 2020 13:52:39 +0100 Message-Id: <20200114125254.4515-16-quintela@redhat.com> In-Reply-To: <20200114125254.4515-1-quintela@redhat.com> References: <20200114125254.4515-1-quintela@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-MC-Unique: cATNDCvfOGqZhOhtdNQrfw-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 207.211.31.81 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: , Cc: Laurent Vivier , Peter Maydell , Thomas Huth , Corey Minyard , =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= , Eduardo Habkost , Juan Quintela , Stefan Weil , Jason Wang , "Michael S. Tsirkin" , "Dr. David Alan Gilbert" , Stefan Berger , Yury Kotov , qemu-arm@nongnu.org, qemu-ppc@nongnu.org, =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= , Paolo Bonzini , Richard Henderson , David Gibson Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: Yury Kotov Usually, incoming migration coroutine yields to the main loop while its IO-channel is waiting for data to receive. But there is a case when RAM migration and data receive have the same speed: VM with huge zeroed RAM. In this case, IO-channel won't read and thus the main loop is stuck and for instance, it doesn't respond to QMP commands. For this case, yield periodically, but not too often, so as not to affect the speed of migration. Signed-off-by: Yury Kotov Reviewed-by: Juan Quintela Signed-off-by: Juan Quintela --- migration/ram.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/migration/ram.c b/migration/ram.c index aa6cc7d47a..0c6992db9a 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -4246,7 +4246,7 @@ static void colo_flush_ram_cache(void) */ static int ram_load_precopy(QEMUFile *f) { - int flags =3D 0, ret =3D 0, invalid_flags =3D 0, len =3D 0; + int flags =3D 0, ret =3D 0, invalid_flags =3D 0, len =3D 0, i =3D 0; /* ADVISE is earlier, it shows the source has the postcopy capability = on */ bool postcopy_advised =3D postcopy_is_advised(); if (!migrate_use_compression()) { @@ -4258,6 +4258,17 @@ static int ram_load_precopy(QEMUFile *f) void *host =3D NULL; uint8_t ch; =20 + /* + * Yield periodically to let main loop run, but an iteration of + * the main loop is expensive, so do it each some iterations + */ + if ((i & 32767) =3D=3D 0 && qemu_in_coroutine()) { + aio_co_schedule(qemu_get_current_aio_context(), + qemu_coroutine_self()); + qemu_coroutine_yield(); + } + i++; + addr =3D qemu_get_be64(f); flags =3D addr & ~TARGET_PAGE_MASK; addr &=3D TARGET_PAGE_MASK; --=20 2.24.1