From mboxrd@z Thu Jan 1 00:00:00 1970 From: Li Zefan Subject: [PATCH v2 05/10] cpuset: re-structure update_cpumask() a bit Date: Wed, 5 Jun 2013 17:15:59 +0800 Message-ID: <51AF01CF.1070706@huawei.com> References: <51AF0183.8070602@huawei.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <51AF0183.8070602-hv44wF8Li93QT0dZR+AlfA@public.gmane.org> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Tejun Heo Cc: Cgroups , Containers , LKML Check if cpus_allowed is to be changed before calling validate_change(). This won't change any behavior, but later it will allow us to do this: # mkdir /cpuset/child # echo $$ > /cpuset/child/tasks /* empty cpuset */ # echo > /cpuset/child/cpuset.cpus /* do nothing, won't fail */ Without this patch, the last operation will fail. Signed-off-by: Li Zefan --- kernel/cpuset.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/kernel/cpuset.c b/kernel/cpuset.c index 51f8e1d..535dce6 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -856,14 +856,15 @@ static int update_cpumask(struct cpuset *cs, struct cpuset *trialcs, if (!cpumask_subset(trialcs->cpus_allowed, cpu_active_mask)) return -EINVAL; } - retval = validate_change(cs, trialcs); - if (retval < 0) - return retval; /* Nothing to do if the cpus didn't change */ if (cpumask_equal(cs->cpus_allowed, trialcs->cpus_allowed)) return 0; + retval = validate_change(cs, trialcs); + if (retval < 0) + return retval; + retval = heap_init(&heap, PAGE_SIZE, GFP_KERNEL, NULL); if (retval) return retval; -- 1.8.0.2