Re: [patch 2/2 v3]raid5: create multiple threads to handle stripes

[NeilBrown <neilb@suse.de>]

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On Thu, 7 Mar 2013 15:31:23 +0800 Shaohua Li <shli@kernel.org> wrote:

> Hi Neil,
> 
> I just noticed this one is missed. It used to be in your branch, but get
> dropped some time. Is anything I missed? I can resend it if you like.
> 
> Thanks,
> Shaohua
> 
> On Thu, Aug 09, 2012 at 04:58:08PM +0800, Shaohua Li wrote:
> > This is a new tempt to make raid5 handle stripes in multiple threads, as
> > suggested by Neil to have maxium flexibility and better numa binding. It
> > basically is a combination of my first and second generation patches. By
> > default, no multiple thread is enabled (all stripes are handled by raid5d).
> > 
> > An example to enable multiple threads:
> > #echo 3 > /sys/block/md0/md/auxthread_number
> > This will create 3 auxiliary threads to handle stripes. The threads can run
> > on any cpus and handle stripes produced by any cpus.
> > 
> > #echo 1-3 > /sys/block/md0/md/auxth0/cpulist
> > This will bind auxiliary thread 0 to cpu 1-3, and this thread will only handle
> > stripes produced by cpu 1-3. User tool can further change the thread's
> > affinity, but the thread can only handle stripes produced by cpu 1-3 till the
> > sysfs entry is changed again.
> > 
> > If stripes produced by a CPU aren't handled by any auxiliary thread, such
> > stripes will be handled by raid5d. Otherwise, raid5d doesn't handle any
> > stripes.


Hi Shaohua,
 I still have this sitting in my queue, but I haven't had a chance to look at
 is properly yet - I'm sorry about that.  I'll try to get to it soon.

NeilBrown

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