On 03.10.19 19:15, Vladimir Sementsov-Ogievskiy wrote: > No reason to limit buffered copy to one cluster. Let's allow up to 1 > MiB. > > Signed-off-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com> > --- > include/block/block-copy.h | 2 +- > block/block-copy.c | 44 +++++++++++++++++++++++++++----------- > 2 files changed, 32 insertions(+), 14 deletions(-)
Er, oops, looks like I was a bit quick there...
> @@ -100,17 +101,28 @@ BlockCopyState *block_copy_state_new(BdrvChild *source,
> BdrvChild *target,
> .mem = qemu_co_shared_amount_new(BLOCK_COPY_MAX_MEM),
> };
>
> - s->copy_range_size = QEMU_ALIGN_DOWN(max_transfer, cluster_size),
> - /*
> - * Set use_copy_range, consider the following:
> - * 1. Compression is not supported for copy_range.
> - * 2. copy_range does not respect max_transfer (it's a TODO), so we
> factor
> - * that in here. If max_transfer is smaller than the
> job->cluster_size,
> - * we do not use copy_range (in that case it's zero after aligning
> down
> - * above).
> - */
> - s->use_copy_range =
> - !(write_flags & BDRV_REQ_WRITE_COMPRESSED) && s->copy_range_size > 0;
> + if (max_transfer < cluster_size) {
> + /*
> + * copy_range does not respect max_transfer. We don't want to bother
> + * with requests smaller than block-copy cluster size, so fallback to
> + * buffered copying (read and write respect max_transfer on their
> + * behalf).
> + */
> + s->use_copy_range = false;
> + s->copy_size = cluster_size;
> + } else if (write_flags & BDRV_REQ_WRITE_COMPRESSED) {
> + /* Compression is not supported for copy_range */
> + s->use_copy_range = false;
> + s->copy_size = MAX(cluster_size, BLOCK_COPY_MAX_BUFFER);
> + } else {
> + /*
> + * copy_range does not respect max_transfer (it's a TODO), so we
> factor
> + * that in here.
> + */
> + s->use_copy_range = true;
> + s->copy_size = MIN(MAX(cluster_size, BLOCK_COPY_MAX_COPY_RANGE),
This is already part of max_transfer, isn’t it?
(That doesn’t make it wrong, but I think max_transfer will always be
less than or equal to MAX(cluster_size, BLOCK_COPY_MAX_COPY_RANGE) anyway.)
Max
> + QEMU_ALIGN_DOWN(max_transfer, cluster_size));
signature.asc
Description: OpenPGP digital signature
