Re: ext4 write performance regression in 3.6-rc1 on RAID0/5

2012-08-22 Thread NeilBrown
On Wed, 22 Aug 2012 13:47:07 -0700 Dan Williams wrote: > On Tue, Aug 21, 2012 at 11:00 PM, NeilBrown wrote: > > On Wed, 22 Aug 2012 11:57:02 +0800 Yuanhan Liu > > wrote: > > > >> > >> -#define NR_STRIPES 256 > >> +#define NR_STRIPES 1024 > > > > Changing one magic number int

Re: ext4 write performance regression in 3.6-rc1 on RAID0/5

2012-08-22 Thread Dan Williams
On Tue, Aug 21, 2012 at 11:00 PM, NeilBrown wrote: > On Wed, 22 Aug 2012 11:57:02 +0800 Yuanhan Liu > wrote: > >> >> -#define NR_STRIPES 256 >> +#define NR_STRIPES 1024 > > Changing one magic number into another magic number might help your case, but > it not really a general

Re: ext4 write performance regression in 3.6-rc1 on RAID0/5

2012-08-22 Thread Andreas Dilger
On 2012-08-22, at 12:00 AM, NeilBrown wrote: > On Wed, 22 Aug 2012 11:57:02 +0800 Yuanhan Liu > wrote: >> >> -#define NR_STRIPES 256 >> +#define NR_STRIPES 1024 > > Changing one magic number into another magic number might help your case, but > it not really a general solution.

Re: ext4 write performance regression in 3.6-rc1 on RAID0/5

2012-08-21 Thread Yuanhan Liu
On Wed, Aug 22, 2012 at 04:00:25PM +1000, NeilBrown wrote: > On Wed, 22 Aug 2012 11:57:02 +0800 Yuanhan Liu > wrote: > > > > > -#define NR_STRIPES 256 > > +#define NR_STRIPES 1024 > > Changing one magic number into another magic number might help your case, but > it not really

Re: ext4 write performance regression in 3.6-rc1 on RAID0/5

2012-08-21 Thread NeilBrown
On Wed, 22 Aug 2012 11:57:02 +0800 Yuanhan Liu wrote: > > -#define NR_STRIPES 256 > +#define NR_STRIPES 1024 Changing one magic number into another magic number might help your case, but it not really a general solution. Possibly making sure that max_nr_stripes is at least

Re: ext4 write performance regression in 3.6-rc1 on RAID0/5

2012-08-21 Thread Shaohua Li
On 8/22/12 11:57 AM, Yuanhan Liu wrote: On Fri, Aug 17, 2012 at 10:25:26PM +0800, Fengguang Wu wrote: > [CC md list] > > On Fri, Aug 17, 2012 at 09:40:39AM -0400, Theodore Ts'o wrote: >> On Fri, Aug 17, 2012 at 02:09:15PM +0800, Fengguang Wu wrote: >>> Ted, >>> >>> I find ext4 write performance

Re: ext4 write performance regression in 3.6-rc1 on RAID0/5

2012-08-21 Thread Fengguang Wu
On Tue, Aug 21, 2012 at 05:42:21PM +0800, Fengguang Wu wrote: > On Sat, Aug 18, 2012 at 06:44:57AM +1000, NeilBrown wrote: > > On Fri, 17 Aug 2012 22:25:26 +0800 Fengguang Wu > > wrote: > > > > > [CC md list] > > > > > > On Fri, Aug 17, 2012 at 09:40:39AM -0400, Theodore Ts'o wrote: > > > > On F

Re: ext4 write performance regression in 3.6-rc1 on RAID0/5

2012-08-21 Thread Fengguang Wu
On Sat, Aug 18, 2012 at 06:44:57AM +1000, NeilBrown wrote: > On Fri, 17 Aug 2012 22:25:26 +0800 Fengguang Wu > wrote: > > > [CC md list] > > > > On Fri, Aug 17, 2012 at 09:40:39AM -0400, Theodore Ts'o wrote: > > > On Fri, Aug 17, 2012 at 02:09:15PM +0800, Fengguang Wu wrote: > > > > Ted, > > > >

Re: ext4 write performance regression in 3.6-rc1 on RAID0/5

2012-08-17 Thread NeilBrown
On Fri, 17 Aug 2012 22:25:26 +0800 Fengguang Wu wrote: > [CC md list] > > On Fri, Aug 17, 2012 at 09:40:39AM -0400, Theodore Ts'o wrote: > > On Fri, Aug 17, 2012 at 02:09:15PM +0800, Fengguang Wu wrote: > > > Ted, > > > > > > I find ext4 write performance dropped by 3.3% on average in the > > >

Re: ext4 write performance regression in 3.6-rc1 on RAID0/5

2012-08-17 Thread Theodore Ts'o
On Fri, Aug 17, 2012 at 11:13:18PM +0800, Fengguang Wu wrote: > > Obviously the major regressions happen to the 100dd over raid cases. > Some 10dd cases are also impacted. > > The attached graphs show that everything becomes more fluctuated in > 3.6.0-rc1 for the lkp-nex04/RAID0-12HDD-thresh=8G/e

Re: ext4 write performance regression in 3.6-rc1 on RAID0/5

2012-08-17 Thread Fengguang Wu
[CC md list] On Fri, Aug 17, 2012 at 09:40:39AM -0400, Theodore Ts'o wrote: > On Fri, Aug 17, 2012 at 02:09:15PM +0800, Fengguang Wu wrote: > > Ted, > > > > I find ext4 write performance dropped by 3.3% on average in the > > 3.6-rc1 merge window. xfs and btrfs are fine. > > > > Two machines are