From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Zijlstra Subject: [PATCH v2 26/44] time/tick-broadcast: Remove RCU_NONIDLE usage Date: Mon, 19 Sep 2022 12:00:05 +0200 Message-ID: <20220919101522.089180678@infradead.org> References: <20220919095939.761690562@infradead.org> Mime-Version: 1.0 Return-path: DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Type:MIME-Version:References: Subject:Cc:To:From:Date:Message-ID:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:In-Reply-To; bh=mpoCVwwSlcWMSbFc2ASY4TLxAbRobKK8wUXUoaGZ7qA=; b=cj1X0QBCj4rEPJK9GObBzWTx35 yUxQlVQ1TOAuoawyKARtVWxn7IU/9qHBrZZPqIQpdqT7KHlDJUgKdBkboSYzBMzTbI3lIpsteALlu P/tCS8I0VezPGN+bHLt32BmoUT0HZ9HHzPOeun7K1jgNagz2NRCyXl20/ck4xfe89fjeBwNIZteLX t9cNRIWeyPuRTK5EoMeWNlVQq93og/uw4o+pCSmSt/c5NbzawPhYZvlo7QgJjtVvrpgpwuKMQovs3 k49FYWWzFhzHBF/vhCzCmkL817YNPt2Xk/S3dx+QQaVTOFYHx+/OQbDydKkFwE0tEXzU+yiQ0uC1h U9nUJLZA==; List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: peterz@infradead.org 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 No callers left that have already disabled RCU. Signed-off-by: Peter Zijlstra (Intel) Acked-by: Mark Rutland --- kernel/time/tick-broadcast-hrtimer.c | 29 ++++++++++++----------------- 1 file changed, 12 insertions(+), 17 deletions(-) --- a/kernel/time/tick-broadcast-hrtimer.c +++ b/kernel/time/tick-broadcast-hrtimer.c @@ -56,25 +56,20 @@ static int bc_set_next(ktime_t expires, * hrtimer callback function is currently running, then * hrtimer_start() cannot move it and the timer stays on the CPU on * which it is assigned at the moment. + */ + hrtimer_start(&bctimer, expires, HRTIMER_MODE_ABS_PINNED_HARD); + /* + * The core tick broadcast mode expects bc->bound_on to be set + * correctly to prevent a CPU which has the broadcast hrtimer + * armed from going deep idle. * - * As this can be called from idle code, the hrtimer_start() - * invocation has to be wrapped with RCU_NONIDLE() as - * hrtimer_start() can call into tracing. + * As tick_broadcast_lock is held, nothing can change the cpu + * base which was just established in hrtimer_start() above. So + * the below access is safe even without holding the hrtimer + * base lock. */ - RCU_NONIDLE( { - hrtimer_start(&bctimer, expires, HRTIMER_MODE_ABS_PINNED_HARD); - /* - * The core tick broadcast mode expects bc->bound_on to be set - * correctly to prevent a CPU which has the broadcast hrtimer - * armed from going deep idle. - * - * As tick_broadcast_lock is held, nothing can change the cpu - * base which was just established in hrtimer_start() above. So - * the below access is safe even without holding the hrtimer - * base lock. - */ - bc->bound_on = bctimer.base->cpu_base->cpu; - } ); + bc->bound_on = bctimer.base->cpu_base->cpu; + return 0; }