From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46476) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fRCsX-00063O-My for qemu-devel@nongnu.org; Fri, 08 Jun 2018 04:36:14 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fRCsW-0000PR-Tf for qemu-devel@nongnu.org; Fri, 08 Jun 2018 04:36:13 -0400 Received: from mga09.intel.com ([134.134.136.24]:58067) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fRCsW-0000OZ-Kj for qemu-devel@nongnu.org; Fri, 08 Jun 2018 04:36:12 -0400 From: Wei Wang Date: Fri, 8 Jun 2018 16:10:39 +0800 Message-Id: <1528445443-43406-3-git-send-email-wei.w.wang@intel.com> In-Reply-To: <1528445443-43406-1-git-send-email-wei.w.wang@intel.com> References: <1528445443-43406-1-git-send-email-wei.w.wang@intel.com> Subject: [Qemu-devel] [PATCH v8 2/6] migration: use bitmap_mutex in migration_bitmap_clear_dirty List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org, virtio-dev@lists.oasis-open.org, mst@redhat.com, quintela@redhat.com, dgilbert@redhat.com Cc: peterx@redhat.com, pbonzini@redhat.com, wei.w.wang@intel.com, liliang.opensource@gmail.com, yang.zhang.wz@gmail.com, quan.xu0@gmail.com, nilal@redhat.com, riel@redhat.com 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 --- migration/ram.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/migration/ram.c b/migration/ram.c index c53e836..2eabbe9 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -1093,11 +1093,14 @@ static inline bool migration_bitmap_clear_dirty(RAMState *rs, { bool ret; + qemu_mutex_lock(&rs->bitmap_mutex); ret = test_and_clear_bit(page, rb->bmap); if (ret) { rs->migration_dirty_pages--; } + qemu_mutex_unlock(&rs->bitmap_mutex); + return ret; } -- 1.8.3.1