Re: cfq performance gap

2006-12-13 Thread Miquel van Smoorenburg
In article <[EMAIL PROTECTED]>, Chen, Kenneth W <[EMAIL PROTECTED]> wrote: >Miquel van Smoorenburg wrote on Wednesday, December 13, 2006 1:57 AM >> Chen, Kenneth W <[EMAIL PROTECTED]> wrote: >> >This rawio test plows through sequential I/O and modulo each small record >> >over number of threads. S

RE: cfq performance gap

2006-12-13 Thread Chen, Kenneth W
Miquel van Smoorenburg wrote on Wednesday, December 13, 2006 1:57 AM > Chen, Kenneth W <[EMAIL PROTECTED]> wrote: > >This rawio test plows through sequential I/O and modulo each small record > >over number of threads. So each thread appears to be non-contiguous within > >its own process context, o

Re: cfq performance gap

2006-12-13 Thread Miquel van Smoorenburg
In article <[EMAIL PROTECTED]>, Chen, Kenneth W <[EMAIL PROTECTED]> wrote: >This rawio test plows through sequential I/O and modulo each small record >over number of threads. So each thread appears to be non-contiguous within >its own process context, overall request hitting the device are sequent

Re: cfq performance gap

2006-12-12 Thread Jens Axboe
On Tue, Dec 12 2006, AVANTIKA R. MATHUR wrote: > >That said, I might add some logic to detect when we can cheaply switch > >queues instead of waiting for a new request from the same queue. > >Averaging slice times over a period of time instead of 1:1 with that > >logic, should help cases like this

RE: cfq performance gap

2006-12-12 Thread Chen, Kenneth W
AVANTIKA R. MATHUR wrote on Tuesday, December 12, 2006 5:33 PM > >> rawio is actually performing sequential reads, but I don't believe it is > >> purely sequential with the multiple processes. > >> I am currently running the test with longer runtimes and will post > >> results once it is complete.

Re: cfq performance gap

2006-12-12 Thread AVANTIKA R. MATHUR
Jens Axboe wrote: On Fri, Dec 08 2006, Avantika Mathur wrote: On Fri, 2006-12-08 at 13:05 +0100, Jens Axboe wrote: On Thu, Dec 07 2006, Avantika Mathur wrote: Hi Jens, (you probably noticed now, but the [EMAIL PROTECTED] email is no longer valid) I saw that, th

Re: cfq performance gap

2006-12-11 Thread Jens Axboe
On Fri, Dec 08 2006, Avantika Mathur wrote: > On Fri, 2006-12-08 at 13:05 +0100, Jens Axboe wrote: > > On Thu, Dec 07 2006, Avantika Mathur wrote: > > > Hi Jens, > > > > (you probably noticed now, but the [EMAIL PROTECTED] email is no longer > > valid) > > I saw that, thanks! > > > I've noticed a

Re: cfq performance gap

2006-12-08 Thread Avantika Mathur
On Fri, 2006-12-08 at 13:05 +0100, Jens Axboe wrote: > On Thu, Dec 07 2006, Avantika Mathur wrote: > > Hi Jens, > > (you probably noticed now, but the [EMAIL PROTECTED] email is no longer > valid) I saw that, thanks! > > I've noticed a performance gap between the cfq scheduler and other io > > sc

Re: cfq performance gap

2006-12-08 Thread Jens Axboe
On Thu, Dec 07 2006, Avantika Mathur wrote: > Hi Jens, (you probably noticed now, but the [EMAIL PROTECTED] email is no longer valid) > I've noticed a performance gap between the cfq scheduler and other io > schedulers when running the rawio benchmark. > Results from rawio on 2.6.19, cfq and no

cfq performance gap

2006-12-07 Thread Avantika Mathur
Hi Jens, I've noticed a performance gap between the cfq scheduler and other io schedulers when running the rawio benchmark. Results from rawio on 2.6.19, cfq and noop schedulers: CFQ: procs devicenum read KB/sec I/O Ops/sec - --- -- --- --