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 09A5AC33CB1 for ; Tue, 14 Jan 2020 09:38:40 +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 C98372084D for ; Tue, 14 Jan 2020 09:38:39 +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="eOFciKy5" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C98372084D 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]:35326 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1irIek-0003H7-LO for qemu-devel@archiver.kernel.org; Tue, 14 Jan 2020 04:38:38 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:57734) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1irIUb-0006qM-2F for qemu-devel@nongnu.org; Tue, 14 Jan 2020 04:28:10 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1irIUZ-0006ek-Ry for qemu-devel@nongnu.org; Tue, 14 Jan 2020 04:28:08 -0500 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:55454 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1irIUZ-0006eS-Ni for qemu-devel@nongnu.org; Tue, 14 Jan 2020 04:28:07 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1578994087; 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=ynLvDJfV4kUr7Pu6PZ24xc1KIuICA5kAdzwdWYoRAQo=; b=eOFciKy5T9cQaVKD0x4SyvYAWpW3qB1Gteah84ZUksWf6/UpsXuyyKxXr80EeqpKLoKZ/c X90+vFAZk+z9KE37WB3l1RsyCMWX402R7rxnH5V4MYL4kMmaBd3WCEMXg5hqKr472lKeKS 7XgL99eOBWbYatH0L7lBhGulvY1k+g8= 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-350-N1f5REKCMNKMnrWrZ18yCg-1; Tue, 14 Jan 2020 04:28:04 -0500 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 63E3F1800D78; Tue, 14 Jan 2020 09:28:02 +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 453B9384; Tue, 14 Jan 2020 09:27:53 +0000 (UTC) From: Juan Quintela To: qemu-devel@nongnu.org Subject: [PULL 14/29] migration/ram: Yield periodically to the main loop Date: Tue, 14 Jan 2020 10:25:51 +0100 Message-Id: <20200114092606.1761-15-quintela@redhat.com> In-Reply-To: <20200114092606.1761-1-quintela@redhat.com> References: <20200114092606.1761-1-quintela@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-MC-Unique: N1f5REKCMNKMnrWrZ18yCg-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: 205.139.110.120 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 , Corey Minyard , Thomas Huth , =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= , Eduardo Habkost , "Michael S. Tsirkin" , Peter Maydell , Stefan Weil , Jason Wang , Juan Quintela , "Dr. David Alan Gilbert" , Yury Kotov , qemu-arm@nongnu.org, qemu-ppc@nongnu.org, =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= , Paolo Bonzini , David Gibson , Richard Henderson , Stefan Berger 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 1ec5c10561..5cd066467c 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