From mboxrd@z Thu Jan 1 00:00:00 1970 From: Frederic Weisbecker Subject: Re: [PATCH v2 08/44] cpuidle,imx6: Push RCU-idle into driver Date: Mon, 19 Sep 2022 17:17:34 +0200 Message-ID: <20220919151734.GB62211@lothringen> References: <20220919095939.761690562@infradead.org> <20220919101520.869531945@infradead.org> <20220919144941.GA62211@lothringen> Mime-Version: 1.0 Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1663600657; bh=SGRWSsWxhYnFNcVdXVanCp7r8VhObbFain7vrJ2pf9o=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=fxVxz+v2ZKRYGR2RcB+jwqcdhOAyWFuA63mrtcEpyRTpMkbyS6WHs4N4WpL6wD55y MEw4vseCOHKlzHluXBoBp/tNbhBozucjByJQwggqB8cSL766iSR/fB5p7HP2XX3V5a W432aviHiF1CtVbY9+02lVZyqI6r7f0Y+oEmkgLbQeCLJ6mZ8QHUtL9Cb1Rt7pnsGN oU9BgJeognmYR5a7tpyKmtArG/qTrOVW6g6oNhiIq3bF6GOaiMj1jdkgNeNp7u/R+2 PWnZiOvApDwvdE77MAQCyvfpVSOU+ZSH1CmsYL840fIy4Yva2osOuqdAr10RKbdLw3 uLMmSqj+LM5sA== Content-Disposition: inline In-Reply-To: List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Peter Zijlstra Cc: richard.henderson@linaro.org, ink@jurassic.park.msu.ru, mattst88@gmail.com, vgupta@kernel.org, linux@armlinux.org.uk, ulli.kroll@googlemail.com, linus.walleij@linaro.org, shawnguo@kernel.org, Sascha Hauer , kernel@pengutronix.de, festevam@gmail.com, linux-imx@nxp.com, tony@atomide.com, khilman@kernel.org, catalin.marinas@arm.com, will@kernel.org, guoren@kernel.org, bcain@quicinc.com, chenhuacai@kernel.org, kernel@xen0n.name, geert@linux-m68k.org, sammy@sammy.net, monstr@monstr.eu, tsbogend@alpha.franken.de, dinguyen@kernel.org, jonas@southpole.se, stefan.kristiansson@saunalahti.fi, shorne@gmail.com, James.Bottomley@hansenpartnership.com, deller@gmx.de, mpe@ellerman.id.au, npiggin@gmail.com, christophe.leroy@csgroup.eu, paul.walmsley@sifive.com, palmer@dabbel On Mon, Sep 19, 2022 at 05:03:04PM +0200, Peter Zijlstra wrote: > On Mon, Sep 19, 2022 at 04:49:41PM +0200, Frederic Weisbecker wrote: > > On Mon, Sep 19, 2022 at 11:59:47AM +0200, Peter Zijlstra wrote: > > > Doing RCU-idle outside the driver, only to then temporarily enable it > > > again, at least twice, before going idle is daft. > > > > > > Signed-off-by: Peter Zijlstra (Intel) > > > --- > > > arch/arm/mach-imx/cpuidle-imx6sx.c | 5 ++++- > > > 1 file changed, 4 insertions(+), 1 deletion(-) > > > > > > --- a/arch/arm/mach-imx/cpuidle-imx6sx.c > > > +++ b/arch/arm/mach-imx/cpuidle-imx6sx.c > > > @@ -47,7 +47,9 @@ static int imx6sx_enter_wait(struct cpui > > > cpu_pm_enter(); > > > cpu_cluster_pm_enter(); > > > > > > + ct_idle_enter(); > > > cpu_suspend(0, imx6sx_idle_finish); > > > + ct_idle_exit(); > > > > > > cpu_cluster_pm_exit(); > > > cpu_pm_exit(); > > > @@ -87,7 +89,8 @@ static struct cpuidle_driver imx6sx_cpui > > > */ > > > .exit_latency = 300, > > > .target_residency = 500, > > > - .flags = CPUIDLE_FLAG_TIMER_STOP, > > > + .flags = CPUIDLE_FLAG_TIMER_STOP | > > > + CPUIDLE_FLAG_RCU_IDLE, > > > .enter = imx6sx_enter_wait, > > > > There is a second one below that also uses imx6sx_enter_wait. > > Oh, above you mean; but only @index==2 gets us into the whole PM crud. > @index==1 is fine afaict. Ah ok, got it, hence why you didn't touch cpu_do_idle()... May need to comment that somewhere... Reviewed-by: Frederic Weisbecker Thanks!