From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org,
linux-rt-users <linux-rt-users@vger.kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Carsten Emde <C.Emde@osadl.org>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
John Kacur <jkacur@redhat.com>, <stable-rt@vger.kernel.org>
Subject: [PATCH RT 08/19] kernel/hotplug: restore original cpu mask oncpu/down
Date: Sun, 08 Sep 2013 11:14:03 -0400 [thread overview]
Message-ID: <20130908151447.072858173@goodmis.org> (raw)
In-Reply-To: <20130908151355.362583092@goodmis.org>
[-- Attachment #1: 0008-kernel-hotplug-restore-original-cpu-mask-oncpu-down.patch --]
[-- Type: text/plain, Size: 1820 bytes --]
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
If a task which is allowed to run only on CPU X puts CPU Y down then it
will be allowed on all CPUs but the on CPU Y after it comes back from
kernel. This patch ensures that we don't lose the initial setting unless
the CPU the task is running is going down.
Cc: stable-rt@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
kernel/cpu.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 22063f3..16ec791 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -563,6 +563,7 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
.hcpu = hcpu,
};
cpumask_var_t cpumask;
+ cpumask_var_t cpumask_org;
if (num_online_cpus() == 1)
return -EBUSY;
@@ -573,6 +574,12 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
/* Move the downtaker off the unplug cpu */
if (!alloc_cpumask_var(&cpumask, GFP_KERNEL))
return -ENOMEM;
+ if (!alloc_cpumask_var(&cpumask_org, GFP_KERNEL)) {
+ free_cpumask_var(cpumask);
+ return -ENOMEM;
+ }
+
+ cpumask_copy(cpumask_org, tsk_cpus_allowed(current));
cpumask_andnot(cpumask, cpu_online_mask, cpumask_of(cpu));
set_cpus_allowed_ptr(current, cpumask);
free_cpumask_var(cpumask);
@@ -581,7 +588,8 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
if (mycpu == cpu) {
printk(KERN_ERR "Yuck! Still on unplug CPU\n!");
migrate_enable();
- return -EBUSY;
+ err = -EBUSY;
+ goto restore_cpus;
}
cpu_hotplug_begin();
@@ -639,6 +647,9 @@ out_cancel:
cpu_hotplug_done();
if (!err)
cpu_notify_nofail(CPU_POST_DEAD | mod, hcpu);
+restore_cpus:
+ set_cpus_allowed_ptr(current, cpumask_org);
+ free_cpumask_var(cpumask_org);
return err;
}
--
1.7.10.4
next prev parent reply other threads:[~2013-09-08 15:59 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-09-08 15:13 [PATCH RT 00/19] 3.6.11.8-rt41-rc1 stable review Steven Rostedt
2013-09-08 15:13 ` [PATCH RT 01/19] sched/workqueue: Only wake up idle workers if not blocked on sleeping spin lock Steven Rostedt
2013-09-08 15:13 ` [PATCH RT 02/19] x86/mce: fix mce timer interval Steven Rostedt
2013-09-08 15:13 ` [PATCH RT 03/19] genirq: Set irq thread to RT priority on creation Steven Rostedt
2013-09-08 15:13 ` [PATCH RT 04/19] list_bl.h: make list head locking RT safe Steven Rostedt
2013-09-08 15:14 ` [PATCH RT 05/19] list_bl.h: fix it for for !SMP && !DEBUG_SPINLOCK Steven Rostedt
2013-09-08 15:14 ` [PATCH RT 06/19] timers: prepare for full preemption improve Steven Rostedt
2013-09-08 15:14 ` [PATCH RT 07/19] kernel/cpu: fix cpu down problem if kthreads cpu is going down Steven Rostedt
2013-09-08 15:14 ` Steven Rostedt [this message]
2013-09-08 15:14 ` [PATCH RT 09/19] gpu: i915: allow the user not to do the wbinvd Steven Rostedt
2013-09-08 15:14 ` [PATCH RT 10/19] drm/i915: drop trace_i915_gem_ring_dispatch on rt Steven Rostedt
2013-09-08 15:14 ` [PATCH RT 11/19] sched: Distangle worker accounting from rqlock Steven Rostedt
2013-09-08 15:14 ` [PATCH RT 12/19] rt,ntp: Move call to schedule_delayed_work() to helper thread Steven Rostedt
2013-09-08 15:14 ` [PATCH RT 13/19] hpsa: fix warning with smp_processor_id() in preemptible section Steven Rostedt
2013-09-08 15:14 ` [PATCH RT 14/19] hwlat-detector: Update hwlat_detector to add outer loop detection Steven Rostedt
2013-09-08 15:14 ` [PATCH RT 15/19] hwlat-detect/trace: Export trace_clock_local for hwlat-detector Steven Rostedt
2013-09-08 15:14 ` [PATCH RT 16/19] hwlat-detector: Use trace_clock_local if available Steven Rostedt
2013-09-08 15:14 ` [PATCH RT 17/19] hwlat-detector: Use thread instead of stop machine Steven Rostedt
2013-09-08 15:14 ` [PATCH RT 18/19] genirq: do not invoke the affinity callback via a workqueue Steven Rostedt
2013-09-08 15:14 ` [PATCH RT 19/19] Linux 3.6.11.8-rt41-rc1 Steven Rostedt
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20130908151447.072858173@goodmis.org \
--to=rostedt@goodmis.org \
--cc=C.Emde@osadl.org \
--cc=bigeasy@linutronix.de \
--cc=jkacur@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-rt-users@vger.kernel.org \
--cc=stable-rt@vger.kernel.org \
--cc=tglx@linutronix.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
Powered by JetHome