From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:60229) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ad7R9-0003ho-5B for qemu-devel@nongnu.org; Mon, 07 Mar 2016 21:31:52 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ad7R7-0004eN-U3 for qemu-devel@nongnu.org; Mon, 07 Mar 2016 21:31:51 -0500 Date: Tue, 8 Mar 2016 10:31:37 +0800 From: Fam Zheng Message-ID: <20160308023137.GE7119@ad.usersys.redhat.com> References: <1456564857-29160-1-git-send-email-famz@redhat.com> <1456564857-29160-10-git-send-email-famz@redhat.com> <56D4CD83.3020305@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <56D4CD83.3020305@redhat.com> Subject: Re: [Qemu-devel] [Qemu-block] [PATCH v3 09/15] block: Support meta dirty bitmap List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: John Snow Cc: Vladimir Sementsov-Ogievskiy , qemu-devel@nongnu.org, qemu-block@nongnu.org On Mon, 02/29 18:00, John Snow wrote: > > > On 02/27/2016 04:20 AM, Fam Zheng wrote: > > The added group of operations enables tracking of the changed bits in > > the dirty bitmap. > > > > Signed-off-by: Fam Zheng > > --- > > block/dirty-bitmap.c | 51 ++++++++++++++++++++++++++++++++++++++++++++ > > include/block/dirty-bitmap.h | 9 ++++++++ > > 2 files changed, 60 insertions(+) > > > > diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c > > index 16f73b2..5f19320 100644 > > --- a/block/dirty-bitmap.c > > +++ b/block/dirty-bitmap.c > > @@ -38,6 +38,7 @@ > > */ > > struct BdrvDirtyBitmap { > > HBitmap *bitmap; /* Dirty sector bitmap implementation */ > > + HBitmap *meta; /* Meta dirty bitmap */ > > BdrvDirtyBitmap *successor; /* Anonymous child; implies frozen status */ > > char *name; /* Optional non-empty unique ID */ > > int64_t size; /* Size of the bitmap (Number of sectors) */ > > @@ -103,6 +104,56 @@ BdrvDirtyBitmap *bdrv_create_dirty_bitmap(BlockDriverState *bs, > > return bitmap; > > } > > > > +/* bdrv_create_meta_dirty_bitmap > > + * > > + * Create a meta dirty bitmap that tracks the changes of bits in @bitmap. I.e. > > + * when a dirty status bit in @bitmap is changed (either from reset to set or > > + * the other way around), its respective meta dirty bitmap bit will be marked > > + * dirty as well. > > + * > > + * @bitmap: the block dirty bitmap for which to create a meta dirty bitmap. > > + * @chunk_size: how many bytes of bitmap data does each bit in the meta bitmap > > + * track. > > + */ > > +void bdrv_create_meta_dirty_bitmap(BdrvDirtyBitmap *bitmap, > > + int chunk_size) > > +{ > > + assert(!bitmap->meta); > > + bitmap->meta = hbitmap_create_meta(bitmap->bitmap, > > + chunk_size * BITS_PER_BYTE); > > +} > > + > > +void bdrv_release_meta_dirty_bitmap(BdrvDirtyBitmap *bitmap) > > +{ > > + assert(bitmap->meta); > > + hbitmap_free_meta(bitmap->bitmap); > > + bitmap->meta = NULL; > > +} > > + > > +int bdrv_dirty_bitmap_get_meta(BlockDriverState *bs, > > + BdrvDirtyBitmap *bitmap, int64_t sector, > > + int nb_sectors) > > +{ > > + uint64_t i; > > + int gran = bdrv_dirty_bitmap_granularity(bitmap) >> BDRV_SECTOR_BITS; > > + > > + /* To optimize: we can make hbitmap to internally check the range in a > > + * coarse level, or at least do it word by word. */ > > + for (i = sector; i < sector + nb_sectors; i += gran) { > > + if (hbitmap_get(bitmap->meta, i)) { > > + return true; > > + } > > + } > > + return false; > > +} > > + > > +void bdrv_dirty_bitmap_reset_meta(BlockDriverState *bs, > > + BdrvDirtyBitmap *bitmap, int64_t sector, > > + int nb_sectors) > > +{ > > + hbitmap_reset(bitmap->meta, sector, nb_sectors); > > +} > > + > > bool bdrv_dirty_bitmap_frozen(BdrvDirtyBitmap *bitmap) > > { > > return bitmap->successor; > > diff --git a/include/block/dirty-bitmap.h b/include/block/dirty-bitmap.h > > index e1dbd8e..3b27742 100644 > > --- a/include/block/dirty-bitmap.h > > +++ b/include/block/dirty-bitmap.h > > @@ -9,6 +9,9 @@ BdrvDirtyBitmap *bdrv_create_dirty_bitmap(BlockDriverState *bs, > > uint32_t granularity, > > const char *name, > > Error **errp); > > +void bdrv_create_meta_dirty_bitmap(BdrvDirtyBitmap *bitmap, > > + int chunk_size); > > +void bdrv_release_meta_dirty_bitmap(BdrvDirtyBitmap *bitmap); > > int bdrv_dirty_bitmap_create_successor(BlockDriverState *bs, > > BdrvDirtyBitmap *bitmap, > > Error **errp); > > @@ -37,6 +40,12 @@ void bdrv_set_dirty_bitmap(BdrvDirtyBitmap *bitmap, > > int64_t cur_sector, int nr_sectors); > > void bdrv_reset_dirty_bitmap(BdrvDirtyBitmap *bitmap, > > int64_t cur_sector, int nr_sectors); > > +int bdrv_dirty_bitmap_get_meta(BlockDriverState *bs, > > + BdrvDirtyBitmap *bitmap, int64_t sector, > > + int nb_sectors); > > +void bdrv_dirty_bitmap_reset_meta(BlockDriverState *bs, > > + BdrvDirtyBitmap *bitmap, int64_t sector, > > + int nb_sectors); > > BdrvDirtyBitmapIter *bdrv_dirty_iter_new(BdrvDirtyBitmap *bitmap, > > uint64_t first_sector); > > void bdrv_dirty_iter_free(BdrvDirtyBitmapIter *iter); > > > > Do we need to amend the teardown in bdrv_do_release_matching_dirty_bitmap? Will add an "assert(!bm->meta)" there. Fam