From ddd2ef2ce8d693b6e2635a0c20f65744641ff8df Mon Sep 17 00:00:00 2001 From: "Denis V. Lunev" Date: Tue, 28 Apr 2015 10:47:00 +0300 Subject: [PATCH] block/parallels: improve image writing performance further Try to perform IO for the biggest continuous block possible. All blocks abscent in the image are accounted in the same type and preallocation is made for all of them at once. The performance for sequential write is increased from 200 Mb/sec to 235 Mb/sec on my SSD HDD. Signed-off-by: Denis V. Lunev Reviewed-by: Roman Kagan Signed-off-by: Roman Kagan Message-id: 1430207220-24458-28-git-send-email-den@openvz.org CC: Kevin Wolf CC: Stefan Hajnoczi Signed-off-by: Stefan Hajnoczi --- block/parallels.c | 43 +++++++++++++++++++++++-------------------- 1 file changed, 23 insertions(+), 20 deletions(-) diff --git a/block/parallels.c b/block/parallels.c index e7124d97e7..046b56844c 100644 --- a/block/parallels.c +++ b/block/parallels.c @@ -183,43 +183,47 @@ static int64_t block_status(BDRVParallelsState *s, int64_t sector_num, return start_off; } -static int64_t allocate_cluster(BlockDriverState *bs, int64_t sector_num) +static int64_t allocate_clusters(BlockDriverState *bs, int64_t sector_num, + int nb_sectors, int *pnum) { BDRVParallelsState *s = bs->opaque; - uint32_t idx, offset; - int64_t pos; + uint32_t idx, to_allocate, i; + int64_t pos, space; - idx = sector_num / s->tracks; - offset = sector_num % s->tracks; + pos = block_status(s, sector_num, nb_sectors, pnum); + if (pos > 0) { + return pos; + } + idx = sector_num / s->tracks; if (idx >= s->bat_size) { return -EINVAL; } - if (s->bat_bitmap[idx] != 0) { - return bat2sect(s, idx) + offset; - } - pos = bdrv_getlength(bs->file) >> BDRV_SECTOR_BITS; - if (s->data_end + s->tracks > pos) { + to_allocate = (sector_num + *pnum + s->tracks - 1) / s->tracks - idx; + space = to_allocate * s->tracks; + if (s->data_end + space > bdrv_getlength(bs->file) >> BDRV_SECTOR_BITS) { int ret; + space += s->prealloc_size; if (s->prealloc_mode == PRL_PREALLOC_MODE_FALLOCATE) { - ret = bdrv_write_zeroes(bs->file, s->data_end, - s->prealloc_size, 0); + ret = bdrv_write_zeroes(bs->file, s->data_end, space, 0); } else { ret = bdrv_truncate(bs->file, - (s->data_end + s->prealloc_size) << BDRV_SECTOR_BITS); + (s->data_end + space) << BDRV_SECTOR_BITS); } if (ret < 0) { return ret; } } - pos = s->data_end; - s->data_end += s->tracks; - s->bat_bitmap[idx] = cpu_to_le32(pos / s->off_multiplier); + for (i = 0; i < to_allocate; i++) { + s->bat_bitmap[idx + i] = cpu_to_le32(s->data_end / s->off_multiplier); + s->data_end += s->tracks; + bitmap_set(s->bat_dirty_bmap, + bat_entry_off(idx) / s->bat_dirty_block, 1); + } - bitmap_set(s->bat_dirty_bmap, bat_entry_off(idx) / s->bat_dirty_block, 1); - return bat2sect(s, idx) + offset; + return bat2sect(s, idx) + sector_num % s->tracks; } @@ -287,14 +291,13 @@ static coroutine_fn int parallels_co_writev(BlockDriverState *bs, int n, nbytes; qemu_co_mutex_lock(&s->lock); - position = allocate_cluster(bs, sector_num); + position = allocate_clusters(bs, sector_num, nb_sectors, &n); qemu_co_mutex_unlock(&s->lock); if (position < 0) { ret = (int)position; break; } - n = cluster_remainder(s, sector_num, nb_sectors); nbytes = n << BDRV_SECTOR_BITS; qemu_iovec_reset(&hd_qiov); -- 2.11.4.GIT