Re: [Qemu-block] [PATCH v14 1/1] qcow2: skip writing zero buffers to empty COW areas

On 22/5/2019 11:40 PM, Max Reitz wrote: > On 16.05.19 16:27, Anton Nefedov wrote: >> If COW areas of the newly allocated clusters are zeroes on the backing >> image, efficient bdrv_write_zeroes(flags=BDRV_REQ_NO_FALLBACK) can be >> used on the whole cluster instead of writing explicit zero buffers

Re: [Qemu-block] [PATCH v14 1/1] qcow2: skip writing zero buffers to empty COW areas

On 16.05.19 16:27, Anton Nefedov wrote: > If COW areas of the newly allocated clusters are zeroes on the backing > image, efficient bdrv_write_zeroes(flags=BDRV_REQ_NO_FALLBACK) can be > used on the whole cluster instead of writing explicit zero buffers later > in perform_cow(). > > iotest 060: >

Re: [Qemu-block] [PATCH v14 1/1] qcow2: skip writing zero buffers to empty COW areas

On Thu 16 May 2019 04:27:49 PM CEST, Anton Nefedov wrote: > If COW areas of the newly allocated clusters are zeroes on the backing > image, efficient bdrv_write_zeroes(flags=BDRV_REQ_NO_FALLBACK) can be > used on the whole cluster instead of writing explicit zero buffers later > in perform_cow(). >

Re: [Qemu-block] [PATCH v14 1/1] qcow2: skip writing zero buffers to empty COW areas

16.05.2019 17:27, Anton Nefedov wrote: > If COW areas of the newly allocated clusters are zeroes on the backing > image, efficient bdrv_write_zeroes(flags=BDRV_REQ_NO_FALLBACK) can be > used on the whole cluster instead of writing explicit zero buffers later > in perform_cow(). > > iotest 060: > w

[Qemu-block] [PATCH v14 1/1] qcow2: skip writing zero buffers to empty COW areas

If COW areas of the newly allocated clusters are zeroes on the backing image, efficient bdrv_write_zeroes(flags=BDRV_REQ_NO_FALLBACK) can be used on the whole cluster instead of writing explicit zero buffers later in perform_cow(). iotest 060: write to the discarded cluster does not trigger COW an