Re: [RFC PATCH 0/3] restartable sequences v2: fast user-space percpu critical sections

From: Peter Zijlstra
Date: Fri Apr 08 2016 - 07:04:15 EST


On Thu, Apr 07, 2016 at 03:05:26PM -0700, Andy Lutomirski wrote:

> It doesn't, which is what I like about my variant. If the thread
> accesses the protected data structure, though, it should bump the
> sequence count, which will cause the first thread to about when it
> gets scheduled in.

Nope it won't, because that first thread is right at the commit
instruction, nothing will stop it from executing that store and clobbing
what we just wrote.