Messages in this thread | | | Date | Wed, 27 Apr 2016 11:49:35 -0700 | Subject | Re: [GIT PULL] workqueue fixes for v4.6-rc5 | From | Linus Torvalds <> |
| |
On Wed, Apr 27, 2016 at 9:11 AM, Tejun Heo <tj@kernel.org> wrote: > > Unfortunately, we were missing a smp_rmb() after clearing PENDING for > execution, so nothing guaranteed visibility of the changes that a > queueing loser has made, which manifested as a reproducible blk-mq > stall.
That explanation makes no sense. A smp_rmb() after a store makes no sense what-so-ever.
Happily, the code itself does and has a big comment. It's not a "smp_rmb()", it's a full memory barrier. Which *does* make sense as serializing a store wrt a following load.
Linus
| |