* [RFC PATCH] perf/amd: Try to fix some mem allocation failure handling
@ 2014-06-10 9:37 Zhouyi Zhou
2014-06-10 10:36 ` Peter Zijlstra
0 siblings, 1 reply; 2+ messages in thread
From: Zhouyi Zhou @ 2014-06-10 9:37 UTC (permalink / raw)
To: a.p.zijlstra, paulus, mingo, acme, tglx, hpa, x86, linux-kernel
Cc: Zhouyi Zhou, Zhouyi Zhou
This is version 2.0 of "[PATCH 1/1] perf/amd: NULL return of kzalloc_node should be handled"
(http://www.spinics.net/lists/kernel/msg1760689.html),
Try to correctly handle mem allocation failure in perf_event_amd_uncore.c
Signed-off-by: Zhouyi Zhou <yizhouzhou@ict.ac.cn>
---
arch/x86/kernel/cpu/perf_event_amd_uncore.c | 36 ++++++++++++++++++++++++---
1 file changed, 33 insertions(+), 3 deletions(-)
diff --git a/arch/x86/kernel/cpu/perf_event_amd_uncore.c b/arch/x86/kernel/cpu/perf_event_amd_uncore.c
index 3bbdf4c..bdc8e49 100644
--- a/arch/x86/kernel/cpu/perf_event_amd_uncore.c
+++ b/arch/x86/kernel/cpu/perf_event_amd_uncore.c
@@ -294,12 +294,14 @@ static struct amd_uncore *amd_uncore_alloc(unsigned int cpu)
cpu_to_node(cpu));
}
-static void amd_uncore_cpu_up_prepare(unsigned int cpu)
+static int amd_uncore_cpu_up_prepare(unsigned int cpu)
{
struct amd_uncore *uncore;
if (amd_uncore_nb) {
uncore = amd_uncore_alloc(cpu);
+ if (!uncore)
+ return 1;
uncore->cpu = cpu;
uncore->num_counters = NUM_COUNTERS_NB;
uncore->rdpmc_base = RDPMC_BASE_NB;
@@ -311,6 +313,11 @@ static void amd_uncore_cpu_up_prepare(unsigned int cpu)
if (amd_uncore_l2) {
uncore = amd_uncore_alloc(cpu);
+ if (!uncore) {
+ if (amd_uncore_nb)
+ kfree(*per_cpu_ptr(amd_uncore_nb, cpu));
+ return 1;
+ }
uncore->cpu = cpu;
uncore->num_counters = NUM_COUNTERS_L2;
uncore->rdpmc_base = RDPMC_BASE_L2;
@@ -319,6 +326,8 @@ static void amd_uncore_cpu_up_prepare(unsigned int cpu)
uncore->pmu = &amd_l2_pmu;
*per_cpu_ptr(amd_uncore_l2, cpu) = uncore;
}
+
+ return 0;
}
static struct amd_uncore *
@@ -461,7 +470,8 @@ amd_uncore_cpu_notifier(struct notifier_block *self, unsigned long action,
switch (action & ~CPU_TASKS_FROZEN) {
case CPU_UP_PREPARE:
- amd_uncore_cpu_up_prepare(cpu);
+ if (amd_uncore_cpu_up_prepare(cpu))
+ return notifier_from_errno(-ENOMEM),
break;
case CPU_STARTING:
@@ -514,6 +524,8 @@ static int __init amd_uncore_init(void)
if (cpu_has_perfctr_nb) {
amd_uncore_nb = alloc_percpu(struct amd_uncore *);
+ if (!amd_uncore_nb)
+ return -ENOMEM;
perf_pmu_register(&amd_nb_pmu, amd_nb_pmu.name, -1);
printk(KERN_INFO "perf: AMD NB counters detected\n");
@@ -522,6 +534,13 @@ static int __init amd_uncore_init(void)
if (cpu_has_perfctr_l2) {
amd_uncore_l2 = alloc_percpu(struct amd_uncore *);
+ if (!amd_uncore_l2) {
+ if (cpu_has_perfctr_nb) {
+ perf_pmu_unregister(&amd_nb_pmu);
+ free_percpu(amd_uncore_nb);
+ }
+ return -ENOMEM;
+ }
perf_pmu_register(&amd_l2_pmu, amd_l2_pmu.name, -1);
printk(KERN_INFO "perf: AMD L2I counters detected\n");
@@ -535,7 +554,18 @@ static int __init amd_uncore_init(void)
/* init cpus already online before registering for hotplug notifier */
for_each_online_cpu(cpu) {
- amd_uncore_cpu_up_prepare(cpu);
+ if (amd_uncore_cpu_up_prepare(cpu)) {
+ if (cpu_has_perfctr_nb) {
+ perf_pmu_unregister(&amd_nb_pmu);
+ free_percpu(amd_uncore_nb);
+ }
+ if (cpu_has_perfctr_l2) {
+ perf_pmu_unregister(&amd_l2_pmu);
+ free_percpu(amd_uncore_l2);
+ }
+ cpu_notifier_register_done();
+ return -ENOMEM;
+ }
smp_call_function_single(cpu, init_cpu_already_online, NULL, 1);
}
--
1.7.10.4
^ permalink raw reply related [flat|nested] 2+ messages in thread* Re: [RFC PATCH] perf/amd: Try to fix some mem allocation failure handling
2014-06-10 9:37 [RFC PATCH] perf/amd: Try to fix some mem allocation failure handling Zhouyi Zhou
@ 2014-06-10 10:36 ` Peter Zijlstra
0 siblings, 0 replies; 2+ messages in thread
From: Peter Zijlstra @ 2014-06-10 10:36 UTC (permalink / raw)
To: Zhouyi Zhou
Cc: paulus, mingo, acme, tglx, hpa, x86, linux-kernel, Zhouyi Zhou
[-- Attachment #1: Type: text/plain, Size: 4171 bytes --]
On Tue, Jun 10, 2014 at 05:37:09PM +0800, Zhouyi Zhou wrote:
> This is version 2.0 of "[PATCH 1/1] perf/amd: NULL return of kzalloc_node should be handled"
> (http://www.spinics.net/lists/kernel/msg1760689.html),
>
> Try to correctly handle mem allocation failure in perf_event_amd_uncore.c
>
> Signed-off-by: Zhouyi Zhou <yizhouzhou@ict.ac.cn>
> ---
> arch/x86/kernel/cpu/perf_event_amd_uncore.c | 36 ++++++++++++++++++++++++---
> 1 file changed, 33 insertions(+), 3 deletions(-)
>
> diff --git a/arch/x86/kernel/cpu/perf_event_amd_uncore.c b/arch/x86/kernel/cpu/perf_event_amd_uncore.c
> index 3bbdf4c..bdc8e49 100644
> --- a/arch/x86/kernel/cpu/perf_event_amd_uncore.c
> +++ b/arch/x86/kernel/cpu/perf_event_amd_uncore.c
> @@ -294,12 +294,14 @@ static struct amd_uncore *amd_uncore_alloc(unsigned int cpu)
> cpu_to_node(cpu));
> }
>
> -static void amd_uncore_cpu_up_prepare(unsigned int cpu)
> +static int amd_uncore_cpu_up_prepare(unsigned int cpu)
> {
> struct amd_uncore *uncore;
>
> if (amd_uncore_nb) {
> uncore = amd_uncore_alloc(cpu);
> + if (!uncore)
> + return 1;
> uncore->cpu = cpu;
> uncore->num_counters = NUM_COUNTERS_NB;
> uncore->rdpmc_base = RDPMC_BASE_NB;
> @@ -311,6 +313,11 @@ static void amd_uncore_cpu_up_prepare(unsigned int cpu)
>
> if (amd_uncore_l2) {
> uncore = amd_uncore_alloc(cpu);
> + if (!uncore) {
> + if (amd_uncore_nb)
> + kfree(*per_cpu_ptr(amd_uncore_nb, cpu));
> + return 1;
> + }
> uncore->cpu = cpu;
> uncore->num_counters = NUM_COUNTERS_L2;
> uncore->rdpmc_base = RDPMC_BASE_L2;
> @@ -319,6 +326,8 @@ static void amd_uncore_cpu_up_prepare(unsigned int cpu)
> uncore->pmu = &amd_l2_pmu;
> *per_cpu_ptr(amd_uncore_l2, cpu) = uncore;
> }
> +
> + return 0;
> }
Maybe return -ENOMEM here already.
> static struct amd_uncore *
> @@ -461,7 +470,8 @@ amd_uncore_cpu_notifier(struct notifier_block *self, unsigned long action,
>
> switch (action & ~CPU_TASKS_FROZEN) {
> case CPU_UP_PREPARE:
> - amd_uncore_cpu_up_prepare(cpu);
> + if (amd_uncore_cpu_up_prepare(cpu))
> + return notifier_from_errno(-ENOMEM),
> break;
>
> case CPU_STARTING:
> @@ -514,6 +524,8 @@ static int __init amd_uncore_init(void)
>
> if (cpu_has_perfctr_nb) {
> amd_uncore_nb = alloc_percpu(struct amd_uncore *);
> + if (!amd_uncore_nb)
> + return -ENOMEM;
> perf_pmu_register(&amd_nb_pmu, amd_nb_pmu.name, -1);
>
> printk(KERN_INFO "perf: AMD NB counters detected\n");
> @@ -522,6 +534,13 @@ static int __init amd_uncore_init(void)
>
> if (cpu_has_perfctr_l2) {
> amd_uncore_l2 = alloc_percpu(struct amd_uncore *);
> + if (!amd_uncore_l2) {
> + if (cpu_has_perfctr_nb) {
> + perf_pmu_unregister(&amd_nb_pmu);
Combined with the below (extra for_each_cpu loop) you might want to
think of the 'normal' error handling goto chain.
err_online:
for_each_online_cpu(cpu2) {
if (cpu2 == cpu)
break;
/* cleanup cpu2 */
}
err_l2:
perf_pmu_unregister(nb);
free_percpu(nb);
err_nb:
return ret;
> + free_percpu(amd_uncore_nb);
> + }
> + return -ENOMEM;
> + }
> perf_pmu_register(&amd_l2_pmu, amd_l2_pmu.name, -1);
Then you can propagate the error here, instead of assuming -ENOMEM.
> printk(KERN_INFO "perf: AMD L2I counters detected\n");
> @@ -535,7 +554,18 @@ static int __init amd_uncore_init(void)
>
> /* init cpus already online before registering for hotplug notifier */
> for_each_online_cpu(cpu) {
> - amd_uncore_cpu_up_prepare(cpu);
> + if (amd_uncore_cpu_up_prepare(cpu)) {
> + if (cpu_has_perfctr_nb) {
> + perf_pmu_unregister(&amd_nb_pmu);
> + free_percpu(amd_uncore_nb);
> + }
> + if (cpu_has_perfctr_l2) {
> + perf_pmu_unregister(&amd_l2_pmu);
> + free_percpu(amd_uncore_l2);
> + }
> + cpu_notifier_register_done();
> + return -ENOMEM;
> + }
> smp_call_function_single(cpu, init_cpu_already_online, NULL, 1);
> }
I think you want a second for_each_online_cpu() loop and undo the work
for the other CPUs before calling unregister etc..
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