Re: blkdev_issue_discard() hangs forever if the underlying storagedevice is removed

[Lukas Czerner]

On Mon, 29 Aug 2011, Lin Ming wrote:

> On Mon, Aug 29, 2011 at 10:42 PM, Lukas Czerner <lczerner@xxxxxxxxxx> wrote:
> > On Mon, 29 Aug 2011, Lin Ming wrote:
> >
> >> On Mon, Aug 29, 2011 at 7:56 PM, Lukas Czerner <lczerner@xxxxxxxxxx> wrote:
> >> >
> >> > Regarding the atomic operations I do not think that implicit memory
> >> > barriers are needed here as atomic_dec_and_test() implies memory
> >>
> >> Which implicit memory barrier you are talking about?
> >
> > smp_mb() at both side of the operation as documented here in
> > Documentation/memory-barriers.txt
> 
> Thanks for the info.
> 
> But I don't follow you ... why that implicit memory barriers are NOT needed?
> 

Oh, I am sorry I have actually wanted to say that *explicit* memory
barriers are no needed in that case. Sorry for the confusion!

Thanks!
-Lukas
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