Re: [PATCH] x86 spinlock: Fix memory corruption on completing completions

[Sasha Levin <sasha.levin@oracle.com>]

On 02/06/2015 02:42 PM, Davidlohr Bueso wrote:
> On Fri, 2015-02-06 at 08:25 -0800, Linus Torvalds wrote:
>> On Fri, Feb 6, 2015 at 6:49 AM, Raghavendra K T
>> <raghavendra.kt@linux.vnet.ibm.com> wrote:
>>> Paravirt spinlock clears slowpath flag after doing unlock.
>> [ fix edited out ]
>>
>> So I'm not going to be applying this for 3.19, because it's much too
>> late and the patch is too scary. Plus the bug probably effectively
>> never shows up in real life (it is probably easy to trigger the
>> speculative *read* but probably never the actual speculative write
>> after dropping the lock last).
>>
>> This will need a lot of testing by the paravirt people - both
>> performance and correctness. So *maybe* for 3.20, but maybe for even
>> later, and then marked for stable, of course.
>>
>> Are there any good paravirt stress-tests that people could run for
>> extended times?
> 
> locktorture inside a VM should give a proper pounding.

Would it catch lifetime issues too? I thought it just tests out correctness.

I tried it and other unrelated stuff broke. I'll send separate mails for that...


Thanks,
Sasha