[dm-devel] dm-crypt parallelization patches

Tejun Heo tj at kernel.org
Tue Apr 9 18:10:31 UTC 2013


Hey,

On Tue, Apr 09, 2013 at 02:08:06PM -0400, Mikulas Patocka wrote:
> > Hmmm? Why not just keep the issuing order along with plugging
> > boundaries?
> 
> What do you mean?
> 
> I used to have a patch that keeps order of requests as they were 
> introduced, but sorting the requests according to sector number is a bit 
> simpler.

You're still destroying the context information.  Please just keep the
issuing order along with plugging boundaries.

> > As I wrote before, please use bio_associate_current().  Currently,
> > dm-crypt is completely messing up all the context information that cfq
> > depends on to schedule IOs.  Of course, it doesn't perform well.
> 
> bio_associate_current() is only valid on a system with cgroups and there 
> are no cgroups on the kernel where I tested it. It is an empty function:
> 
> static inline int bio_associate_current(struct bio *bio) { return -ENOENT; }

Yeah, because blkcg was the only user.  Please feel free to drop the
ifdefs.  It covers both iocontext and cgroup association.

Thanks.

-- 
tejun




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