Am 02.06.2016 um 17:58 hat Denis V. Lunev geschrieben:
> The problem with excessive flushing was found by a couple of performance
> tests:
> - parallel directory tree creation (from 2 processes)
> - 32 cached writes + fsync at the end in a loop
>
> For the first one results improved from 2.6 l
The problem with excessive flushing was found by a couple of performance
tests:
- parallel directory tree creation (from 2 processes)
- 32 cached writes + fsync at the end in a loop
For the first one results improved from 2.6 loops/sec to 3.5 loops/sec.
Each loop creates 10^3 directories with
On Wed, Jun 01, 2016 at 12:07:01PM +0200, Kevin Wolf wrote:
> Am 01.06.2016 um 11:12 hat Denis V. Lunev geschrieben:
> > qcow2_cache_flush() calls bdrv_flush() unconditionally after writing
> > cache entries of a particular cache. This can lead to as many as
> > 2 additional fdatasyncs inside bdrv_
On Wed, Jun 01, 2016 at 12:07:01PM +0200, Kevin Wolf wrote:
> Am 01.06.2016 um 11:12 hat Denis V. Lunev geschrieben:
> > qcow2_cache_flush() calls bdrv_flush() unconditionally after writing
> > cache entries of a particular cache. This can lead to as many as
> > 2 additional fdatasyncs inside bdrv_
Am 01.06.2016 um 11:12 hat Denis V. Lunev geschrieben:
> qcow2_cache_flush() calls bdrv_flush() unconditionally after writing
> cache entries of a particular cache. This can lead to as many as
> 2 additional fdatasyncs inside bdrv_flush.
>
> We can simply skip all fdatasync calls inside qcow2_co_f
qcow2_cache_flush() calls bdrv_flush() unconditionally after writing
cache entries of a particular cache. This can lead to as many as
2 additional fdatasyncs inside bdrv_flush.
We can simply skip all fdatasync calls inside qcow2_co_flush_to_os
as bdrv_flush for sure will do the job. This seriously
