Re: [Qemu-devel] [PATCH v1 01/13] qcow2: alloc space for COW in one chunk

2017-05-26 Thread Kevin Wolf
Am 26.05.2017 um 12:57 hat Denis V. Lunev geschrieben: > On 05/26/2017 11:11 AM, Kevin Wolf wrote: > > > > No. This is what you bypass: > some analysis for the record. > [...] > anyway, this is a good list of things to take into account > within bdrv_allocate. But it is important, that from the >

Re: [Qemu-devel] [PATCH v1 01/13] qcow2: alloc space for COW in one chunk

2017-05-26 Thread Kevin Wolf
Am 26.05.2017 um 10:57 hat Denis V. Lunev geschrieben: > On 05/26/2017 11:11 AM, Kevin Wolf wrote: > > It seems much clearer to me that simply unifying the three write > > requests into a single one is an improvement. And it's easy to do, I > > even had a patch once to do this. The reason that I

Re: [Qemu-devel] [PATCH v1 01/13] qcow2: alloc space for COW in one chunk

2017-05-26 Thread Denis V. Lunev
On 05/26/2017 11:11 AM, Kevin Wolf wrote: > > No. This is what you bypass: some analysis for the record. > * All sanity checks that the block layer does > > * bdrv_inc/dec_in_flight(), which is required for drain to work > correctly. Not doing this will cause crashes. Should not be a problem.

Re: [Qemu-devel] [PATCH v1 01/13] qcow2: alloc space for COW in one chunk

2017-05-26 Thread Anton Nefedov
On 05/26/2017 11:57 AM, Denis V. Lunev wrote: On 05/26/2017 11:11 AM, Kevin Wolf wrote: Am 19.05.2017 um 11:34 hat Anton Nefedov geschrieben: From: "Denis V. Lunev" Currently each single write operation can result in 3 write operations if guest offsets are not cluster

Re: [Qemu-devel] [PATCH v1 01/13] qcow2: alloc space for COW in one chunk

2017-05-26 Thread Denis V. Lunev
On 05/26/2017 11:11 AM, Kevin Wolf wrote: > Am 19.05.2017 um 11:34 hat Anton Nefedov geschrieben: >> From: "Denis V. Lunev" >> >> Currently each single write operation can result in 3 write operations >> if guest offsets are not cluster aligned. One write is performed for the >>

Re: [Qemu-devel] [PATCH v1 01/13] qcow2: alloc space for COW in one chunk

2017-05-26 Thread Kevin Wolf
Am 19.05.2017 um 11:34 hat Anton Nefedov geschrieben: > From: "Denis V. Lunev" > > Currently each single write operation can result in 3 write operations > if guest offsets are not cluster aligned. One write is performed for the > real payload and two for COW-ed areas. Thus the

Re: [Qemu-devel] [PATCH v1 01/13] qcow2: alloc space for COW in one chunk

2017-05-23 Thread Denis V. Lunev
On 05/22/2017 10:00 PM, Eric Blake wrote: > On 05/19/2017 04:34 AM, Anton Nefedov wrote: >> From: "Denis V. Lunev" >> >> Currently each single write operation can result in 3 write operations >> if guest offsets are not cluster aligned. One write is performed for the >> real

Re: [Qemu-devel] [PATCH v1 01/13] qcow2: alloc space for COW in one chunk

2017-05-23 Thread Anton Nefedov
On 05/22/2017 10:00 PM, Eric Blake wrote: On 05/19/2017 04:34 AM, Anton Nefedov wrote: From: "Denis V. Lunev" Currently each single write operation can result in 3 write operations if guest offsets are not cluster aligned. One write is performed for the real payload and two

Re: [Qemu-devel] [PATCH v1 01/13] qcow2: alloc space for COW in one chunk

2017-05-22 Thread Eric Blake
On 05/19/2017 04:34 AM, Anton Nefedov wrote: > From: "Denis V. Lunev" > > Currently each single write operation can result in 3 write operations > if guest offsets are not cluster aligned. One write is performed for the > real payload and two for COW-ed areas. Thus the data