Re: single aio thread is migrated crazily by scheduler

Ming Lei
2019-11-15T14:16:36Z

On Fri, Nov 15, 2019 at 08:09:25AM +0800, Ming Lei wrote:
> On Thu, Nov 14, 2019 at 02:14:34PM +0100, Peter Zijlstra wrote:
> > On Thu, Nov 14, 2019 at 07:31:53PM +0800, Ming Lei wrote:
> > > Hi Guys,
> > >
> > > It is found that single AIO thread is migrated crazely by scheduler, and
> > > the migrate period can be < 10ms. Follows the test a):
> >
> > What does crazy mean? Does it cycle through the L3 mask?
> >
>
> The single thread AIO thread is migrated in several milliseconds once.

Today I found the migrate rate of single fio IO thread can reach
11~12K/sec when I run './xfs_complete 512' on another real machine
(single numa node, 8 cores).

And the number is very close to IOPS of the test, that said the fio
IO thread can be migrated once just when completing one IO on the
scsi_debug device.

Thanks,
Ming