linux-kernel - Re: [PATCH] revocable: Remove redundant synchronize

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <aXDHx6YtqDA4vx_y@tzungbi-laptop>
Date: Wed, 21 Jan 2026 20:34:15 +0800
From: Tzung-Bi Shih <tzungbi@...nel.org>
To: Bartosz Golaszewski <brgl@...nel.org>
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	"Rafael J. Wysocki" <rafael@...nel.org>,
	Danilo Krummrich <dakr@...nel.org>, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] revocable: Remove redundant synchronize_srcu() call

On Wed, Jan 21, 2026 at 11:38:18AM +0100, Bartosz Golaszewski wrote:
> On Wed, Jan 21, 2026 at 5:03 AM Tzung-Bi Shih <tzungbi@...nel.org> wrote:
> >
> > When allocating a revocable provider via revocable_provider_alloc(),
> > there is no revocable consumers (i.e., RCU readers) yet.  Remove the
> > redundant synchronize_srcu() call to save cycles.
> >
> > Signed-off-by: Tzung-Bi Shih <tzungbi@...nel.org>
> > ---
> > To address the performance impact reported in
> > https://lore.kernel.org/linux-gpio/CAMRc=McrFa42mNWmZtD1HKKKZ+USUKpQAAME50wbfxPM7L72gA@mail.gmail.com/.
> >
> >  drivers/base/revocable.c | 1 -
> >  1 file changed, 1 deletion(-)
> >
> > diff --git a/drivers/base/revocable.c b/drivers/base/revocable.c
> > index f6cece275aac..b068e18a847d 100644
> > --- a/drivers/base/revocable.c
> > +++ b/drivers/base/revocable.c
> > @@ -99,7 +99,6 @@ struct revocable_provider *revocable_provider_alloc(void *res)
> >
> >         init_srcu_struct(&rp->srcu);
> >         rcu_assign_pointer(rp->res, res);
> > -       synchronize_srcu(&rp->srcu);
> >         kref_init(&rp->kref);
> >
> >         return rp;
> > --
> > 2.52.0.457.g6b5491de43-goog
> >
> 
> Do you have an up-to-date integration branch with all the series and
> fixes you posted that I could use for testing with GPIO?

Please use
https://git.kernel.org/pub/scm/linux/kernel/git/tzungbi/chrome-platform.git/log/?h=gpio_rev
for the purpose which is based on driver-core-next and gpio/for-current
branches.