From 386a907b37a9321bc5d699bc37104d6ffba1b34d Mon Sep 17 00:00:00 2001 From: Wei Wang Date: Tue, 11 Dec 2018 16:24:49 +0800 Subject: migration: use bitmap_mutex in migration_bitmap_clear_dirty 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(-) (limited to 'migration') 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(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; } -- cgit v1.2.3