* [PATCH] sched/deadline: Test for CPU's presence explicitly
@ 2014-02-17 14:12 Boris Ostrovsky
2014-02-17 14:50 ` Peter Zijlstra
2014-02-21 20:32 ` [tip:sched/urgent] sched/deadline: Test for CPU' s " tip-bot for Boris Ostrovsky
0 siblings, 2 replies; 4+ messages in thread
From: Boris Ostrovsky @ 2014-02-17 14:12 UTC (permalink / raw)
To: mingo, peterz; +Cc: linux-kernel, konrad.wilk, boris.ostrovsky
A hot-removed CPU may have ID that is numerically larger than the number of
existing CPUs in the system (e.g. we can unplug CPU 4 from a system that
has CPUs 0, 1 and 4).
Thus the WARN_ONs should check whether the CPU in question is currently
present, not whether its ID value is less than num_present_cpus().
Reported-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
---
kernel/sched/cpudeadline.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/kernel/sched/cpudeadline.c b/kernel/sched/cpudeadline.c
index 045fc74..5b8838b 100644
--- a/kernel/sched/cpudeadline.c
+++ b/kernel/sched/cpudeadline.c
@@ -70,7 +70,7 @@ static void cpudl_heapify(struct cpudl *cp, int idx)
static void cpudl_change_key(struct cpudl *cp, int idx, u64 new_dl)
{
- WARN_ON(idx > num_present_cpus() || idx == IDX_INVALID);
+ WARN_ON(!cpu_present(idx) || idx == IDX_INVALID);
if (dl_time_before(new_dl, cp->elements[idx].dl)) {
cp->elements[idx].dl = new_dl;
@@ -117,7 +117,7 @@ int cpudl_find(struct cpudl *cp, struct task_struct *p,
}
out:
- WARN_ON(best_cpu > num_present_cpus() && best_cpu != -1);
+ WARN_ON(!cpu_present(best_cpu) && best_cpu != -1);
return best_cpu;
}
@@ -137,7 +137,7 @@ void cpudl_set(struct cpudl *cp, int cpu, u64 dl, int is_valid)
int old_idx, new_cpu;
unsigned long flags;
- WARN_ON(cpu > num_present_cpus());
+ WARN_ON(!cpu_present(cpu));
raw_spin_lock_irqsave(&cp->lock, flags);
old_idx = cp->cpu_to_idx[cpu];
--
1.8.1.4
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH] sched/deadline: Test for CPU's presence explicitly
2014-02-17 14:12 [PATCH] sched/deadline: Test for CPU's presence explicitly Boris Ostrovsky
@ 2014-02-17 14:50 ` Peter Zijlstra
2014-02-17 15:49 ` Juri Lelli
2014-02-21 20:32 ` [tip:sched/urgent] sched/deadline: Test for CPU' s " tip-bot for Boris Ostrovsky
1 sibling, 1 reply; 4+ messages in thread
From: Peter Zijlstra @ 2014-02-17 14:50 UTC (permalink / raw)
To: Boris Ostrovsky; +Cc: mingo, linux-kernel, konrad.wilk, juri.lelli
On Mon, Feb 17, 2014 at 09:12:33AM -0500, Boris Ostrovsky wrote:
> A hot-removed CPU may have ID that is numerically larger than the number of
> existing CPUs in the system (e.g. we can unplug CPU 4 from a system that
> has CPUs 0, 1 and 4).
>
> Thus the WARN_ONs should check whether the CPU in question is currently
> present, not whether its ID value is less than num_present_cpus().
>
> Reported-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Thanks!, please also always CC the author of the code in question.
> ---
> kernel/sched/cpudeadline.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/kernel/sched/cpudeadline.c b/kernel/sched/cpudeadline.c
> index 045fc74..5b8838b 100644
> --- a/kernel/sched/cpudeadline.c
> +++ b/kernel/sched/cpudeadline.c
> @@ -70,7 +70,7 @@ static void cpudl_heapify(struct cpudl *cp, int idx)
>
> static void cpudl_change_key(struct cpudl *cp, int idx, u64 new_dl)
> {
> - WARN_ON(idx > num_present_cpus() || idx == IDX_INVALID);
> + WARN_ON(!cpu_present(idx) || idx == IDX_INVALID);
>
> if (dl_time_before(new_dl, cp->elements[idx].dl)) {
> cp->elements[idx].dl = new_dl;
> @@ -117,7 +117,7 @@ int cpudl_find(struct cpudl *cp, struct task_struct *p,
> }
>
> out:
> - WARN_ON(best_cpu > num_present_cpus() && best_cpu != -1);
> + WARN_ON(!cpu_present(best_cpu) && best_cpu != -1);
>
> return best_cpu;
> }
> @@ -137,7 +137,7 @@ void cpudl_set(struct cpudl *cp, int cpu, u64 dl, int is_valid)
> int old_idx, new_cpu;
> unsigned long flags;
>
> - WARN_ON(cpu > num_present_cpus());
> + WARN_ON(!cpu_present(cpu));
>
> raw_spin_lock_irqsave(&cp->lock, flags);
> old_idx = cp->cpu_to_idx[cpu];
> --
> 1.8.1.4
>
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] sched/deadline: Test for CPU's presence explicitly
2014-02-17 14:50 ` Peter Zijlstra
@ 2014-02-17 15:49 ` Juri Lelli
0 siblings, 0 replies; 4+ messages in thread
From: Juri Lelli @ 2014-02-17 15:49 UTC (permalink / raw)
To: Peter Zijlstra, Boris Ostrovsky; +Cc: mingo, linux-kernel, konrad.wilk
On 02/17/2014 03:50 PM, Peter Zijlstra wrote:
> On Mon, Feb 17, 2014 at 09:12:33AM -0500, Boris Ostrovsky wrote:
>> A hot-removed CPU may have ID that is numerically larger than the number of
>> existing CPUs in the system (e.g. we can unplug CPU 4 from a system that
>> has CPUs 0, 1 and 4).
>>
>> Thus the WARN_ONs should check whether the CPU in question is currently
>> present, not whether its ID value is less than num_present_cpus().
>>
>> Reported-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
>> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
>
> Thanks!, please also always CC the author of the code in question.
>
Thanks!
- Juri
>> ---
>> kernel/sched/cpudeadline.c | 6 +++---
>> 1 file changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/kernel/sched/cpudeadline.c b/kernel/sched/cpudeadline.c
>> index 045fc74..5b8838b 100644
>> --- a/kernel/sched/cpudeadline.c
>> +++ b/kernel/sched/cpudeadline.c
>> @@ -70,7 +70,7 @@ static void cpudl_heapify(struct cpudl *cp, int idx)
>>
>> static void cpudl_change_key(struct cpudl *cp, int idx, u64 new_dl)
>> {
>> - WARN_ON(idx > num_present_cpus() || idx == IDX_INVALID);
>> + WARN_ON(!cpu_present(idx) || idx == IDX_INVALID);
>>
>> if (dl_time_before(new_dl, cp->elements[idx].dl)) {
>> cp->elements[idx].dl = new_dl;
>> @@ -117,7 +117,7 @@ int cpudl_find(struct cpudl *cp, struct task_struct *p,
>> }
>>
>> out:
>> - WARN_ON(best_cpu > num_present_cpus() && best_cpu != -1);
>> + WARN_ON(!cpu_present(best_cpu) && best_cpu != -1);
>>
>> return best_cpu;
>> }
>> @@ -137,7 +137,7 @@ void cpudl_set(struct cpudl *cp, int cpu, u64 dl, int is_valid)
>> int old_idx, new_cpu;
>> unsigned long flags;
>>
>> - WARN_ON(cpu > num_present_cpus());
>> + WARN_ON(!cpu_present(cpu));
>>
>> raw_spin_lock_irqsave(&cp->lock, flags);
>> old_idx = cp->cpu_to_idx[cpu];
>> --
>> 1.8.1.4
>>
^ permalink raw reply [flat|nested] 4+ messages in thread
* [tip:sched/urgent] sched/deadline: Test for CPU' s presence explicitly
2014-02-17 14:12 [PATCH] sched/deadline: Test for CPU's presence explicitly Boris Ostrovsky
2014-02-17 14:50 ` Peter Zijlstra
@ 2014-02-21 20:32 ` tip-bot for Boris Ostrovsky
1 sibling, 0 replies; 4+ messages in thread
From: tip-bot for Boris Ostrovsky @ 2014-02-21 20:32 UTC (permalink / raw)
To: linux-tip-commits
Cc: linux-kernel, hpa, mingo, konrad.wilk, boris.ostrovsky, peterz,
rostedt, tglx, juri.lelli
Commit-ID: 82b95800b256205cff2eeab5bbd03430d2d0f20d
Gitweb: http://git.kernel.org/tip/82b95800b256205cff2eeab5bbd03430d2d0f20d
Author: Boris Ostrovsky <boris.ostrovsky@oracle.com>
AuthorDate: Mon, 17 Feb 2014 09:12:33 -0500
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitDate: Fri, 21 Feb 2014 21:27:10 +0100
sched/deadline: Test for CPU's presence explicitly
A hot-removed CPU may have ID that is numerically larger than the number of
existing CPUs in the system (e.g. we can unplug CPU 4 from a system that
has CPUs 0, 1 and 4).
Thus the WARN_ONs should check whether the CPU in question is currently
present, not whether its ID value is less than num_present_cpus().
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Juri Lelli <juri.lelli@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Reported-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1392646353-1874-1-git-send-email-boris.ostrovsky@oracle.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
kernel/sched/cpudeadline.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/kernel/sched/cpudeadline.c b/kernel/sched/cpudeadline.c
index 045fc74..5b8838b 100644
--- a/kernel/sched/cpudeadline.c
+++ b/kernel/sched/cpudeadline.c
@@ -70,7 +70,7 @@ static void cpudl_heapify(struct cpudl *cp, int idx)
static void cpudl_change_key(struct cpudl *cp, int idx, u64 new_dl)
{
- WARN_ON(idx > num_present_cpus() || idx == IDX_INVALID);
+ WARN_ON(!cpu_present(idx) || idx == IDX_INVALID);
if (dl_time_before(new_dl, cp->elements[idx].dl)) {
cp->elements[idx].dl = new_dl;
@@ -117,7 +117,7 @@ int cpudl_find(struct cpudl *cp, struct task_struct *p,
}
out:
- WARN_ON(best_cpu > num_present_cpus() && best_cpu != -1);
+ WARN_ON(!cpu_present(best_cpu) && best_cpu != -1);
return best_cpu;
}
@@ -137,7 +137,7 @@ void cpudl_set(struct cpudl *cp, int cpu, u64 dl, int is_valid)
int old_idx, new_cpu;
unsigned long flags;
- WARN_ON(cpu > num_present_cpus());
+ WARN_ON(!cpu_present(cpu));
raw_spin_lock_irqsave(&cp->lock, flags);
old_idx = cp->cpu_to_idx[cpu];
^ permalink raw reply related [flat|nested] 4+ messages in thread
end of thread, other threads:[~2014-02-21 20:33 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2014-02-17 14:12 [PATCH] sched/deadline: Test for CPU's presence explicitly Boris Ostrovsky
2014-02-17 14:50 ` Peter Zijlstra
2014-02-17 15:49 ` Juri Lelli
2014-02-21 20:32 ` [tip:sched/urgent] sched/deadline: Test for CPU' s " tip-bot for Boris Ostrovsky
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.