From nobody Sun Feb 8 12:28:05 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1551872730282840.2588548353731; Wed, 6 Mar 2019 03:45:30 -0800 (PST) Received: from localhost ([127.0.0.1]:59871 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1h1UzG-0007oJ-8k for importer@patchew.org; Wed, 06 Mar 2019 06:45:26 -0500 Received: from eggs.gnu.org ([209.51.188.92]:43705) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1h1UxG-0006Ur-BJ for qemu-devel@nongnu.org; Wed, 06 Mar 2019 06:43:23 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1h1UxF-0005Ij-HG for qemu-devel@nongnu.org; Wed, 06 Mar 2019 06:43:22 -0500 Received: from mx1.redhat.com ([209.132.183.28]:45652) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1h1UxF-0005IG-9Z for qemu-devel@nongnu.org; Wed, 06 Mar 2019 06:43:21 -0500 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 856C63082E0F; Wed, 6 Mar 2019 11:43:20 +0000 (UTC) Received: from dgilbert-t580.localhost (ovpn-117-163.ams2.redhat.com [10.36.117.163]) by smtp.corp.redhat.com (Postfix) with ESMTP id A741A1001E61; Wed, 6 Mar 2019 11:43:18 +0000 (UTC) From: "Dr. David Alan Gilbert (git)" To: qemu-devel@nongnu.org, quintela@redhat.com, peterx@redhat.com, marcel.apfelbaum@gmail.com, wei.w.wang@intel.com, yury-kotov@yandex-team.ru, chen.zhang@intel.com Date: Wed, 6 Mar 2019 11:42:20 +0000 Message-Id: <20190306114227.9125-16-dgilbert@redhat.com> In-Reply-To: <20190306114227.9125-1-dgilbert@redhat.com> References: <20190306114227.9125-1-dgilbert@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.46]); Wed, 06 Mar 2019 11:43:20 +0000 (UTC) Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL 15/22] migration: use bitmap_mutex in migration_bitmap_clear_dirty 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: armbru@redhat.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Content-Type: text/plain; charset="utf-8" From: Wei Wang The bitmap mutex is used to synchronize threads to update the dirty bitmap and the migration_dirty_pages counter. For example, the free page optimization clears bits of free pages from the bitmap in an iothread context. This patch makes migration_bitmap_clear_dirty update the bitmap and counter under the mutex. Signed-off-by: Wei Wang CC: Dr. David Alan Gilbert CC: Juan Quintela CC: Michael S. Tsirkin CC: Peter Xu Reviewed-by: Peter Xu Message-Id: <1544516693-5395-4-git-send-email-wei.w.wang@intel.com> Signed-off-by: Dr. David Alan Gilbert --- migration/ram.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/migration/ram.c b/migration/ram.c index 01315edd66..0747873ca9 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -342,7 +342,7 @@ struct RAMState { uint64_t target_page_count; /* number of dirty bits in the bitmap */ uint64_t migration_dirty_pages; - /* protects modification of the bitmap */ + /* Protects modification of the bitmap and migration dirty pages */ QemuMutex bitmap_mutex; /* The RAMBlock used in the last src_page_requests */ RAMBlock *last_req_rb; @@ -1590,11 +1590,14 @@ static inline bool migration_bitmap_clear_dirty(RAM= State *rs, { bool ret; =20 + qemu_mutex_lock(&rs->bitmap_mutex); ret =3D test_and_clear_bit(page, rb->bmap); =20 if (ret) { rs->migration_dirty_pages--; } + qemu_mutex_unlock(&rs->bitmap_mutex); + return ret; } =20 --=20 2.20.1