From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-x241.google.com (mail-pf0-x241.google.com [IPv6:2607:f8b0:400e:c00::241]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3wnmyj2LK0zDqLt for ; Wed, 14 Jun 2017 23:03:09 +1000 (AEST) Received: by mail-pf0-x241.google.com with SMTP id w12so16683847pfk.0 for ; Wed, 14 Jun 2017 06:03:09 -0700 (PDT) From: Nicholas Piggin To: linuxppc-dev@lists.ozlabs.org Cc: Nicholas Piggin , Michael Ellerman , Vaidyanathan Srinivasan , "Gautham R . Shenoy" , "Rafael J . Wysocki" , Daniel Lezcano , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 1/3] cpuidle: powerpc: cpuidle set polling before enabling irqs Date: Wed, 14 Jun 2017 23:02:39 +1000 Message-Id: <20170614130241.19865-2-npiggin@gmail.com> In-Reply-To: <20170614130241.19865-1-npiggin@gmail.com> References: <20170614130241.19865-1-npiggin@gmail.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , local_irq_enable can cause interrupts to be taken which could take significant amount of processing time. The idle process should set its polling flag before this, so another process that wakes it during this time will not have to send an IPI. Expand the TIF_POLLING_NRFLAG coverage to as large as possible. Reviewed-by: Gautham R. Shenoy Signed-off-by: Nicholas Piggin --- drivers/cpuidle/cpuidle-powernv.c | 4 +++- drivers/cpuidle/cpuidle-pseries.c | 3 ++- 2 files changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/cpuidle/cpuidle-powernv.c b/drivers/cpuidle/cpuidle-powernv.c index 45eaf06462ae..77bc50ad9f57 100644 --- a/drivers/cpuidle/cpuidle-powernv.c +++ b/drivers/cpuidle/cpuidle-powernv.c @@ -51,9 +51,10 @@ static int snooze_loop(struct cpuidle_device *dev, { u64 snooze_exit_time; - local_irq_enable(); set_thread_flag(TIF_POLLING_NRFLAG); + local_irq_enable(); + snooze_exit_time = get_tb() + snooze_timeout; ppc64_runlatch_off(); HMT_very_low(); @@ -66,6 +67,7 @@ static int snooze_loop(struct cpuidle_device *dev, ppc64_runlatch_on(); clear_thread_flag(TIF_POLLING_NRFLAG); smp_mb(); + return index; } diff --git a/drivers/cpuidle/cpuidle-pseries.c b/drivers/cpuidle/cpuidle-pseries.c index 166ccd711ec9..7b12bb2ea70f 100644 --- a/drivers/cpuidle/cpuidle-pseries.c +++ b/drivers/cpuidle/cpuidle-pseries.c @@ -62,9 +62,10 @@ static int snooze_loop(struct cpuidle_device *dev, unsigned long in_purr; u64 snooze_exit_time; + set_thread_flag(TIF_POLLING_NRFLAG); + idle_loop_prolog(&in_purr); local_irq_enable(); - set_thread_flag(TIF_POLLING_NRFLAG); snooze_exit_time = get_tb() + snooze_timeout; while (!need_resched()) { -- 2.11.0