Re: [PATCH v2 0/6] kernfs: proposed locking and concurrency improvement

Ian Kent
2020-12-11T02:19:45Z

On Fri, 2020-12-11 at 10:01 +0800, Ian Kent wrote:
>
> > For the patches, there is a mutex_lock in kn->attr_mutex, as Tejun
> > mentioned here
> > (https://lore.kernel.org/lkml/X8fe0cmu+aq1gi7O@mtj.duckdns.org/),
> > maybe a global
> > rwsem for kn->iattr will be better??
>
> I wasn't sure about that, IIRC a spin lock could be used around the
> initial check and checked again at the end which would probably have
> been much faster but much less conservative and a bit more ugly so
> I just went the conservative path since there was so much change
> already.

Sorry, I hadn't looked at Tejun's reply yet and TBH didn't remember
it.

Based on what Tejun said it sounds like that needs work.

Ian