diff options
| author | Wei Wang | 2018-12-11 09:24:49 +0100 |
|---|---|---|
| committer | Dr. David Alan Gilbert | 2019-03-06 11:49:18 +0100 |
| commit | 386a907b37a9321bc5d699bc37104d6ffba1b34d (patch) | |
| tree | b6e035c4fbb1140daba18fa2ad4a2c8316ce246e /migration | |
| parent | bitmap: bitmap_count_one_with_offset (diff) | |
| download | qemu-386a907b37a9321bc5d699bc37104d6ffba1b34d.tar.gz qemu-386a907b37a9321bc5d699bc37104d6ffba1b34d.tar.xz qemu-386a907b37a9321bc5d699bc37104d6ffba1b34d.zip | |
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 <wei.w.wang@intel.com>
CC: Dr. David Alan Gilbert <dgilbert@redhat.com>
CC: Juan Quintela <quintela@redhat.com>
CC: Michael S. Tsirkin <mst@redhat.com>
CC: Peter Xu <peterx@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Message-Id: <1544516693-5395-4-git-send-email-wei.w.wang@intel.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Diffstat (limited to 'migration')
| -rw-r--r-- | migration/ram.c | 5 |
1 files changed, 4 insertions, 1 deletions
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; } |