Re: [PATCH v3 0/8] Convert barrier pairs to acquire/release for better performance

[Jan Kara]

On Wed 02-09-26 10:19:46, Theodore Tso wrote:
> On Wed, Sep 02, 2026 at 03:47:57PM -0500, Jinjie Ruan wrote:
> > 
> > This series converts some existing smp_wmb()/smp_rmb() barrier pairs to
> > smp_store_release()/smp_load_acquire() across various subsystems.
> 
> I would like to land the ext4 related patches through the ext4 tree,
> so please detach them from this patch series.  That's because I want
> to be able to monitor the regression testing before sending a pull
> request to Linus.
> 
> More generally, I think we should be looking at this kind of barrier
> conversion on a per site basis.  If there is a bug that isn't notice,
> it can result in a very hard to debug problem.  And if the benefit of
> speeding up a particular code path isn't particularly that great,
> maybe the cost vs benefit vs risk calculation might cause us to decide
> to take a pass on the change.

FWIW I believe each patch in this series is standalone so you can just pick
the ext4 ones yourself. Regarding the benefit, I actually find load_acquire
/ store_release more self-documenting, what exactly they are protecting, so
generally I'm in favor of such conversions if they logically make sense
(i.e., it's really the "prepare some data + store to publish" pattern) -
which was the case in the patches I've reviewed in this series.

								Honza
-- 
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR