On 11/20/2015 05:59 PM, Fam Zheng wrote:
> "s->bitmap" tracks done sectors, we only check bit states without using any
> iterator which HBitmap is good for. Switch to "Bitmap" which is simpler and
> more memory efficient.
>
> Meanwhile, rename it to done_bitmap, to reflect the intention.
>
> Signed-off-by: Fam Zheng <f...@redhat.com>
> ---
> block/backup.c | 11 ++++++-----
> 1 file changed, 6 insertions(+), 5 deletions(-)
>
> diff --git a/block/backup.c b/block/backup.c
> index 3b39119..d408f98 100644
> --- a/block/backup.c
> +++ b/block/backup.c
> @@ -22,6 +22,7 @@
> #include "qapi/qmp/qerror.h"
> #include "qemu/ratelimit.h"
> #include "sysemu/block-backend.h"
> +#include "qemu/bitmap.h"
>
> #define BACKUP_CLUSTER_BITS 16
> #define BACKUP_CLUSTER_SIZE (1 << BACKUP_CLUSTER_BITS)
> @@ -47,7 +48,7 @@ typedef struct BackupBlockJob {
> BlockdevOnError on_target_error;
> CoRwlock flush_rwlock;
> uint64_t sectors_read;
> - HBitmap *bitmap;
> + unsigned long *done_bitmap;
> QLIST_HEAD(, CowRequest) inflight_reqs;
> } BackupBlockJob;
>
> @@ -113,7 +114,7 @@ static int coroutine_fn backup_do_cow(BlockDriverState
> *bs,
> cow_request_begin(&cow_request, job, start, end);
>
> for (; start < end; start++) {
> - if (hbitmap_get(job->bitmap, start)) {
> + if (test_bit(start, job->done_bitmap)) {
> trace_backup_do_cow_skip(job, start);
> continue; /* already copied */
> }
> @@ -164,7 +165,7 @@ static int coroutine_fn backup_do_cow(BlockDriverState
> *bs,
> goto out;
> }
>
> - hbitmap_set(job->bitmap, start, 1);
> + bitmap_set(job->done_bitmap, start, 1);
You can use set_bit() here.
Thanks
Wen Congyang
>
> /* Publish progress, guest I/O counts as progress too. Note that the
> * offset field is an opaque progress value, it is not a disk offset.
> @@ -394,7 +395,7 @@ static void coroutine_fn backup_run(void *opaque)
> start = 0;
> end = DIV_ROUND_UP(job->common.len, BACKUP_CLUSTER_SIZE);
>
> - job->bitmap = hbitmap_alloc(end, 0);
> + job->done_bitmap = bitmap_new(end);
>
> bdrv_set_enable_write_cache(target, true);
> if (target->blk) {
> @@ -475,7 +476,7 @@ static void coroutine_fn backup_run(void *opaque)
> /* wait until pending backup_do_cow() calls have completed */
> qemu_co_rwlock_wrlock(&job->flush_rwlock);
> qemu_co_rwlock_unlock(&job->flush_rwlock);
> - hbitmap_free(job->bitmap);
> + g_free(job->done_bitmap);
>
> if (target->blk) {
> blk_iostatus_disable(target->blk);
>
