Re: Hang on x86-64, 2.6.9-rc3-bk4

[Nick Piggin <nickpiggin@yahoo.com.au>]

Jeff Garzik wrote:
> Nick Piggin wrote:
> 
>> Hi Jeff, my patch has gone to Linus... but if you have time can
>> you just verify that it works without the added cond_resched()
>> please?
>>
>> Thanks.
> 
> 
> 
> Wouldn't akpm's patch be better?
> 

Doesn't actually fix the problem. Well *sigh*, it does but it doesn't
if you know what I mean. It "fixed" the problem because your other
(non-empty) zones will now increase total_scanned, which means the busy
loop will turn into a sleepy loop and you don't notice a problem.

> I would tend to prefer that a one-liner hang fix go into -final, as it's 
> easier to review and verify at this late stage.
> 

Apart from the above, akpm's patch does fix *a* bug, but actually changes
much more common case code a lot more than my patch, and has less obvious
consequences. It really wants a full cycle for performance regressions to
appear.