Re: [PATCH 9/9] block: make blk-throttle preserve the issuing taskon delayed bios

From: Tejun Heo
Date: Fri Feb 17 2012 - 17:17:27 EST


Hello,

On Fri, Feb 17, 2012 at 04:58:14PM -0500, Vivek Goyal wrote:
> blk-throttle is just one of places where we lose submitter's context info.
> There are others too.

Yeah, sure. We do that in quite a few places now.

> As Kent said, doing this at more generic level will probably make sense.
> I think dm layer also might benefit from it. We had issues with losing
> this process context info while bio is being submitted with a helper thread.
>
> https://lkml.org/lkml/2010/10/24/59
>
> But I guess this will require some changes at dm layer too so that it
> takes extra bio->ioc and bio->blkcg references at cloning time.

Yeah, it just needs to make sure %current's ioc is there and call
bio_associate_current() before passing bios to worker. We'll get
there.

Thanks.

--
tejun
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