Re: [Linux-v4.6-rc1] ext4: WARNING: CPU: 2 PID: 2692 at kernel/locking/lockdep.c:2017 __lock_acquire+0x180e/0x2260

Sedat Dilek
2016-05-09T11:37:40Z

On 4/4/16, Peter Zijlstra <peterz@infradead.org> wrote:
> On Mon, Apr 04, 2016 at 05:31:40PM +0200, Sedat Dilek wrote:
>> > +/* https://en.wikipedia.org/wiki/Xorshift#xorshift.2A */
>> > +#define UINT64_C(x) x##ULL
>> > +static inline u64 xorshift64star(u64 x)
>> > +{
>> > + x ^= x >> 12; // a
>> > + x ^= x << 25; // b
>> > + x ^= x >> 27; // c
>> > + return x * UINT64_C(2685821657736338717);
>> > +}
>
>> Will you push that also to peterz/queue.git#locking/urgent?
>
> Only after I've had a play and observed it making any difference; Dmitry
> supposedly has a reproducer, but I've not yet had a moment to try.
>

Hi Peter,

any news on that stuff?
How can someone test this?
How did Dmitry reproduce?

Regards,
- Sedat -