From mboxrd@z Thu Jan 1 00:00:00 1970 From: Darren Hart Subject: Re: [PATCH v2 07/10] futex: use freezable blocking call Date: Thu, 02 May 2013 20:12:58 -0700 Message-ID: <51832B3A.4070703@linux.intel.com> References: <1367458508-9133-1-git-send-email-ccross@android.com> <1367458508-9133-8-git-send-email-ccross@android.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from mga02.intel.com ([134.134.136.20]:51930 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758906Ab3ECDNA (ORCPT ); Thu, 2 May 2013 23:13:00 -0400 In-Reply-To: Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Thomas Gleixner Cc: Colin Cross , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, "Rafael J. Wysocki" , arve@android.com, Tejun Heo , Oleg Nesterov , Andrew Morton , Randy Dunlap , Al Viro On 05/02/2013 12:45 PM, Thomas Gleixner wrote: > On Wed, 1 May 2013, Colin Cross wrote: > >> Avoid waking up every thread sleeping in a futex_wait call during >> suspend and resume by calling a freezable blocking call. Previous >> patches modified the freezer to avoid sending wakeups to threads >> that are blocked in freezable blocking calls. >> >> This call was selected to be converted to a freezable call because >> it doesn't hold any locks or release any resources when interrupted >> that might be needed by another freezing task or a kernel driver >> during suspend, and is a common site where idle userspace tasks are >> blocked. >> >> Signed-off-by: Colin Cross > > Acked-by: Thomas Gleixner Beat me to it :-) Also agreed. Acked-by: Darren Hart > >> --- >> kernel/futex.c | 3 ++- >> 1 file changed, 2 insertions(+), 1 deletion(-) >> >> diff --git a/kernel/futex.c b/kernel/futex.c >> index b26dcfc..d710fae 100644 >> --- a/kernel/futex.c >> +++ b/kernel/futex.c >> @@ -61,6 +61,7 @@ >> #include >> #include >> #include >> +#include >> >> #include >> >> @@ -1807,7 +1808,7 @@ static void futex_wait_queue_me(struct futex_hash_bucket *hb, struct futex_q *q, >> * is no timeout, or if it has yet to expire. >> */ >> if (!timeout || timeout->task) >> - schedule(); >> + freezable_schedule(); >> } >> __set_current_state(TASK_RUNNING); >> } >> -- >> 1.8.2.1 >> >> -- Darren Hart Intel Open Source Technology Center Yocto Project - Technical Lead - Linux Kernel