Re: [PATCH v6 1/4] rcu: Make call_rcu() lazy to save power

From: Joel Fernandes <joel@joelfernandes.org>
To: Uladzislau Rezki <urezki@gmail.com>
Cc: paulmck@kernel.org, rcu@vger.kernel.org,
	linux-kernel@vger.kernel.org, rushikesh.s.kadam@intel.com,
	neeraj.iitr10@gmail.com, frederic@kernel.org,
	rostedt@goodmis.org
Subject: Re: [PATCH v6 1/4] rcu: Make call_rcu() lazy to save power
Date: Tue, 4 Oct 2022 14:06:45 -0400	[thread overview]
Message-ID: <CAEXW_YT9qMJFW0sD-_shDd1PSeY4TefZ4HdbKtm_rqDXZcj-5w@mail.gmail.com> (raw)
In-Reply-To: <YzwafYASrgKZ24uq@pc636>

Hi Vlad,

On Tue, Oct 4, 2022 at 7:35 AM Uladzislau Rezki <urezki@gmail.com> wrote:
>
> > > >>
> > > >> OK. Found the boot up issue. In my case i had 120 seconds delay:
> > > >
> > > > Wow, nice work.
> > > >
> > > >> <snip>
> > > >> diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
> > > >> index 448748e3fba5..a56cfd612e3a 100644
> > > >> --- a/drivers/scsi/scsi_error.c
> > > >> +++ b/drivers/scsi/scsi_error.c
> > > >> @@ -312,7 +312,7 @@ void scsi_eh_scmd_add(struct scsi_cmnd *scmd)
> > > >>        * Ensure that all tasks observe the host state change before the
> > > >>        * host_failed change.
> > > >>        */
> > > >> -       call_rcu(&scmd->rcu, scsi_eh_inc_host_failed);
> > > >> +       call_rcu_flush(&scmd->rcu, scsi_eh_inc_host_failed);
> > > >
> > > > Great! Thanks. I’ll include this and the other one you converted in the next revision.
> > >
> > > By the way, any chance you could check android as well, just to rule out any trouble markers? ChromeOS and your Linux distro are doing well on boot so that’s a good sign.
> > >
> > I will check v6 on Android. I will get back shortly.
> >
> OK. Works and boots well. I do not see any issues with Android so far.
>

That's great news and thank you so much for testing Android and all
your efforts on this work!

 - Joel