Re: [RFT PATCH] blkio: alloc per cpu data from worker thread context(Re: kvm deadlock)

From: Jens Axboe
Date: Tue Dec 20 2011 - 07:49:28 EST


On 2011-12-19 19:27, Vivek Goyal wrote:
> I think reverting the previous series is not going to be simple either. It
> had 13 patches.
>
> https://lkml.org/lkml/2011/5/19/560
>
> By making stats per cpu, I was able to reduce contention on request
> queue lock. Now we shall have to bring the lock back.

That's not going to happen, having that lock in there was a disaster for
small IO on fast devices. It's essentially the limiting factor on
benchmark runs on the RHEL kernels that have it included and enabled...


--
Jens Axboe

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