Re: [PATCH for-4.2 1/4] Revert "qcow2: skip writing zero buffers to empty COW areas"

2019-11-01 Thread Max Reitz
On 01.11.19 16:42, Kevin Wolf wrote: > Am 01.11.2019 um 15:01 hat Max Reitz geschrieben: >> On 01.11.19 13:40, Eric Blake wrote: >>> On 11/1/19 11:00 AM, Max Reitz wrote: This reverts commit c8bb23cbdbe32f5c326365e0a82e1b0e68cdcd8a. This commit causes fundamental performance

Re: [PATCH for-4.2 1/4] Revert "qcow2: skip writing zero buffers to empty COW areas"

2019-11-01 Thread Kevin Wolf
Am 01.11.2019 um 15:01 hat Max Reitz geschrieben: > On 01.11.19 13:40, Eric Blake wrote: > > On 11/1/19 11:00 AM, Max Reitz wrote: > >> This reverts commit c8bb23cbdbe32f5c326365e0a82e1b0e68cdcd8a. > >> > >> This commit causes fundamental performance problems on XFS (because > >> fallocate()

Re: [PATCH for-4.2 1/4] Revert "qcow2: skip writing zero buffers to empty COW areas"

2019-11-01 Thread Max Reitz
On 01.11.19 13:40, Eric Blake wrote: > On 11/1/19 11:00 AM, Max Reitz wrote: >> This reverts commit c8bb23cbdbe32f5c326365e0a82e1b0e68cdcd8a. >> >> This commit causes fundamental performance problems on XFS (because >> fallocate() stalls the AIO pipeline), and as such it is not clear that >> we

Re: [PATCH for-4.2 1/4] Revert "qcow2: skip writing zero buffers to empty COW areas"

2019-11-01 Thread Eric Blake
On 11/1/19 11:00 AM, Max Reitz wrote: This reverts commit c8bb23cbdbe32f5c326365e0a82e1b0e68cdcd8a. This commit causes fundamental performance problems on XFS (because fallocate() stalls the AIO pipeline), and as such it is not clear that we should unconditionally enable this behavior. We

Re: [PATCH for-4.2 1/4] Revert "qcow2: skip writing zero buffers to empty COW areas"

2019-11-01 Thread Vladimir Sementsov-Ogievskiy
01.11.2019 13:00, Max Reitz wrote: > This reverts commit c8bb23cbdbe32f5c326365e0a82e1b0e68cdcd8a. > > This commit causes fundamental performance problems on XFS (because > fallocate() stalls the AIO pipeline), and as such it is not clear that > we should unconditionally enable this behavior. >