From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49871) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gTeKf-0000sz-9E for qemu-devel@nongnu.org; Sun, 02 Dec 2018 21:51:37 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gTeKe-0000bg-JG for qemu-devel@nongnu.org; Sun, 02 Dec 2018 21:51:37 -0500 Received: from mga07.intel.com ([134.134.136.100]:65450) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gTeKe-0000Zq-Am for qemu-devel@nongnu.org; Sun, 02 Dec 2018 21:51:36 -0500 From: Wei Wang Date: Mon, 3 Dec 2018 10:18:27 +0800 Message-Id: <1543803511-34793-4-git-send-email-wei.w.wang@intel.com> In-Reply-To: <1543803511-34793-1-git-send-email-wei.w.wang@intel.com> References: <1543803511-34793-1-git-send-email-wei.w.wang@intel.com> Subject: [Qemu-devel] [PATCH v10 3/7] 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, peterx@redhat.com Cc: pbonzini@redhat.com, liliang.opensource@gmail.com, nilal@redhat.com, riel@redhat.com, wei.w.wang@intel.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 | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/migration/ram.c b/migration/ram.c index 7e7deec..01d267f 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -316,7 +316,7 @@ 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; @@ -1556,11 +1556,14 @@ 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