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

[Lin Ming]

On Mon, Aug 29, 2011 at 11:16 PM, Lukas Czerner <lczerner@xxxxxxxxxx> wrote:
> 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!

Make sense now :)

Thanks.
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