From nobody Tue Feb 10 16:22:09 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zoho.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1496222263208885.3389487616238; Wed, 31 May 2017 02:17:43 -0700 (PDT) Received: from localhost ([::1]:58046 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dFzl6-0000Mg-0g for importer@patchew.org; Wed, 31 May 2017 05:17:40 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33055) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dFzjI-0007jk-4H for qemu-devel@nongnu.org; Wed, 31 May 2017 05:15:48 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dFzjH-0001r5-8t for qemu-devel@nongnu.org; Wed, 31 May 2017 05:15:48 -0400 Received: from mx1.redhat.com ([209.132.183.28]:34338) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dFzjH-0001qy-2t for qemu-devel@nongnu.org; Wed, 31 May 2017 05:15:47 -0400 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 mx1.redhat.com (Postfix) with ESMTPS id 3484F883A4; Wed, 31 May 2017 09:15:46 +0000 (UTC) Received: from secure.mitica (ovpn-116-157.ams2.redhat.com [10.36.116.157]) by smtp.corp.redhat.com (Postfix) with ESMTP id A62B64FA40; Wed, 31 May 2017 09:15:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 3484F883A4 Authentication-Results: ext-mx02.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx02.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=quintela@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 3484F883A4 From: Juan Quintela To: qemu-devel@nongnu.org Date: Wed, 31 May 2017 11:15:35 +0200 Message-Id: <20170531091538.21626-3-quintela@redhat.com> In-Reply-To: <20170531091538.21626-1-quintela@redhat.com> References: <20170531091538.21626-1-quintela@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Wed, 31 May 2017 09:15:46 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL 2/5] migration: keep bytes_xfer_prev init'd to zero 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: lvivier@redhat.com, dgilbert@redhat.com, peterx@redhat.com, Felipe Franciosi Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" From: Felipe Franciosi The first time migration_bitmap_sync() is called, bytes_xfer_prev is set to ram_state.bytes_transferred which is, at this point, zero. The next time migration_bitmap_sync() is called, an iteration has happened and bytes_xfer_prev is set to 'x' bytes. Most likely, more than one second has passed, so the auto converge logic will be triggered and bytes_xfer_now will also be set to 'x' bytes. This condition is currently masked by dirty_rate_high_cnt, which will wait for a few iterations before throttling. It would otherwise always assume zero bytes have been copied and therefore throttle the guest (possibly) prematurely. Given bytes_xfer_prev is only used by the auto convergence logic, it makes sense to only set its value after a check has been made against bytes_xfer_now. Signed-off-by: Felipe Franciosi Reviewed-by: Peter Xu Reviewed-by: Juan Quintela Signed-off-by: Juan Quintela --- migration/ram.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/migration/ram.c b/migration/ram.c index c07a9c0..36bf720 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -673,10 +673,6 @@ static void migration_bitmap_sync(RAMState *rs) =20 rs->bitmap_sync_count++; =20 - if (!rs->bytes_xfer_prev) { - rs->bytes_xfer_prev =3D ram_bytes_transferred(); - } - if (!rs->time_last_bitmap_sync) { rs->time_last_bitmap_sync =3D qemu_clock_get_ms(QEMU_CLOCK_REALTIM= E); } --=20 2.9.4