Re: [BUG] perf and kmemcheck : fatal combination
From: Eric Dumazet
Date: Tue Apr 26 2011 - 08:27:47 EST
Le mardi 26 avril 2011 Ã 12:27 +0200, Eric Dumazet a Ãcrit :
> Le mardi 26 avril 2011 Ã 13:08 +0300, Pekka Enberg a Ãcrit :
>
> > That's just kmemcheck fault handler warning about in_nmi(). You could
> > try to make the relevant perf allocations use __GFP_NOTRACK and/or
> > SLAB_NOTRACK to avoid page faulting in the perf nmi handler.
>
> Yes, I am going to try that, thanks
>
Thats far from trivial, maybe because we dont have NOTRACK api for
percpu allocations ?
I tried without success following patch
diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index 632e5dc..bea4949 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -1632,7 +1632,7 @@ static int validate_event(struct perf_event *event)
struct event_constraint *c;
int ret = 0;
- fake_cpuc = kmalloc(sizeof(*fake_cpuc), GFP_KERNEL | __GFP_ZERO);
+ fake_cpuc = kmalloc(sizeof(*fake_cpuc), GFP_KERNEL | __GFP_ZERO | ___GFP_NOTRACK);
if (!fake_cpuc)
return -ENOMEM;
@@ -1667,7 +1667,7 @@ static int validate_group(struct perf_event *event)
int ret, n;
ret = -ENOMEM;
- fake_cpuc = kmalloc(sizeof(*fake_cpuc), GFP_KERNEL | __GFP_ZERO);
+ fake_cpuc = kmalloc(sizeof(*fake_cpuc), GFP_KERNEL | __GFP_ZERO | ___GFP_NOTRACK);
if (!fake_cpuc)
goto out;
diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c
index 43fa20b..a659b61 100644
--- a/arch/x86/kernel/cpu/perf_event_intel.c
+++ b/arch/x86/kernel/cpu/perf_event_intel.c
@@ -1209,7 +1209,7 @@ static int intel_pmu_cpu_prepare(int cpu)
return NOTIFY_OK;
cpuc->per_core = kzalloc_node(sizeof(struct intel_percore),
- GFP_KERNEL, cpu_to_node(cpu));
+ GFP_KERNEL | ___GFP_NOTRACK, cpu_to_node(cpu));
if (!cpuc->per_core)
return NOTIFY_BAD;
diff --git a/arch/x86/kernel/cpu/perf_event_intel_ds.c b/arch/x86/kernel/cpu/perf_event_intel_ds.c
index bab491b..e921a2f 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_ds.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_ds.c
@@ -84,7 +84,7 @@ static int alloc_pebs_buffer(int cpu)
if (!x86_pmu.pebs)
return 0;
- buffer = kmalloc_node(PEBS_BUFFER_SIZE, GFP_KERNEL | __GFP_ZERO, node);
+ buffer = kmalloc_node(PEBS_BUFFER_SIZE, GFP_KERNEL | __GFP_ZERO | ___GFP_NOTRACK, node);
if (unlikely(!buffer))
return -ENOMEM;
@@ -122,7 +122,7 @@ static int alloc_bts_buffer(int cpu)
if (!x86_pmu.bts)
return 0;
- buffer = kmalloc_node(BTS_BUFFER_SIZE, GFP_KERNEL | __GFP_ZERO, node);
+ buffer = kmalloc_node(BTS_BUFFER_SIZE, GFP_KERNEL | __GFP_ZERO | ___GFP_NOTRACK, node);
if (unlikely(!buffer))
return -ENOMEM;
@@ -155,7 +155,7 @@ static int alloc_ds_buffer(int cpu)
int node = cpu_to_node(cpu);
struct debug_store *ds;
- ds = kmalloc_node(sizeof(*ds), GFP_KERNEL | __GFP_ZERO, node);
+ ds = kmalloc_node(sizeof(*ds), GFP_KERNEL | __GFP_ZERO | ___GFP_NOTRACK, node);
if (unlikely(!ds))
return -ENOMEM;
diff --git a/include/linux/hardirq.h b/include/linux/hardirq.h
index ba36217..8c2e3e6 100644
--- a/include/linux/hardirq.h
+++ b/include/linux/hardirq.h
@@ -211,7 +211,6 @@ extern void irq_exit(void);
#define nmi_enter() \
do { \
ftrace_nmi_enter(); \
- BUG_ON(in_nmi()); \
add_preempt_count(NMI_OFFSET + HARDIRQ_OFFSET); \
lockdep_off(); \
rcu_nmi_enter(); \
diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index 8e81a98..b09ba81 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -2589,14 +2589,14 @@ static int alloc_callchain_buffers(void)
*/
size = offsetof(struct callchain_cpus_entries, cpu_entries[nr_cpu_ids]);
- entries = kzalloc(size, GFP_KERNEL);
+ entries = kzalloc(size, GFP_KERNEL | ___GFP_NOTRACK);
if (!entries)
return -ENOMEM;
size = sizeof(struct perf_callchain_entry) * PERF_NR_CONTEXTS;
for_each_possible_cpu(cpu) {
- entries->cpu_entries[cpu] = kmalloc_node(size, GFP_KERNEL,
+ entries->cpu_entries[cpu] = kmalloc_node(size, GFP_KERNEL | ___GFP_NOTRACK,
cpu_to_node(cpu));
if (!entries->cpu_entries[cpu])
goto fail;
@@ -2756,7 +2756,8 @@ alloc_perf_context(struct pmu *pmu, struct task_struct *task)
{
struct perf_event_context *ctx;
- ctx = kzalloc(sizeof(struct perf_event_context), GFP_KERNEL);
+ ctx = kzalloc(sizeof(struct perf_event_context),
+ GFP_KERNEL | ___GFP_NOTRACK);
if (!ctx)
return NULL;
@@ -3451,7 +3452,7 @@ static void *perf_mmap_alloc_page(int cpu)
int node;
node = (cpu == -1) ? cpu : cpu_to_node(cpu);
- page = alloc_pages_node(node, GFP_KERNEL | __GFP_ZERO, 0);
+ page = alloc_pages_node(node, GFP_KERNEL | __GFP_ZERO | ___GFP_NOTRACK, 0);
if (!page)
return NULL;
@@ -3468,7 +3469,7 @@ perf_buffer_alloc(int nr_pages, long watermark, int cpu, int flags)
size = sizeof(struct perf_buffer);
size += nr_pages * sizeof(void *);
- buffer = kzalloc(size, GFP_KERNEL);
+ buffer = kzalloc(size, GFP_KERNEL | ___GFP_NOTRACK);
if (!buffer)
goto fail;
@@ -3585,7 +3586,7 @@ perf_buffer_alloc(int nr_pages, long watermark, int cpu, int flags)
size = sizeof(struct perf_buffer);
size += sizeof(void *);
- buffer = kzalloc(size, GFP_KERNEL);
+ buffer = kzalloc(size, GFP_KERNEL | ___GFP_NOTRACK);
if (!buffer)
goto fail;
@@ -4841,7 +4842,7 @@ static void perf_event_mmap_event(struct perf_mmap_event *mmap_event)
* need to add enough zero bytes after the string to handle
* the 64bit alignment we do later.
*/
- buf = kzalloc(PATH_MAX + sizeof(u64), GFP_KERNEL);
+ buf = kzalloc(PATH_MAX + sizeof(u64), GFP_KERNEL | ___GFP_NOTRACK);
if (!buf) {
name = strncpy(tmp, "//enomem", sizeof(tmp));
goto got_name;
@@ -5385,7 +5386,7 @@ static int swevent_hlist_get_cpu(struct perf_event *event, int cpu)
if (!swevent_hlist_deref(swhash) && cpu_online(cpu)) {
struct swevent_hlist *hlist;
- hlist = kzalloc(sizeof(*hlist), GFP_KERNEL);
+ hlist = kzalloc(sizeof(*hlist), GFP_KERNEL | ___GFP_NOTRACK);
if (!hlist) {
err = -ENOMEM;
goto exit;
@@ -5969,7 +5970,7 @@ static int pmu_dev_alloc(struct pmu *pmu)
{
int ret = -ENOMEM;
- pmu->dev = kzalloc(sizeof(struct device), GFP_KERNEL);
+ pmu->dev = kzalloc(sizeof(struct device), GFP_KERNEL | ___GFP_NOTRACK);
if (!pmu->dev)
goto out;
@@ -6170,7 +6171,7 @@ perf_event_alloc(struct perf_event_attr *attr, int cpu,
return ERR_PTR(-EINVAL);
}
- event = kzalloc(sizeof(*event), GFP_KERNEL);
+ event = kzalloc(sizeof(*event), GFP_KERNEL | ___GFP_NOTRACK);
if (!event)
return ERR_PTR(-ENOMEM);
@@ -7222,7 +7223,8 @@ static void __cpuinit perf_event_init_cpu(int cpu)
if (swhash->hlist_refcount > 0) {
struct swevent_hlist *hlist;
- hlist = kzalloc_node(sizeof(*hlist), GFP_KERNEL, cpu_to_node(cpu));
+ hlist = kzalloc_node(sizeof(*hlist), GFP_KERNEL | ___GFP_NOTRACK,
+ cpu_to_node(cpu));
WARN_ON(!hlist);
rcu_assign_pointer(swhash->swevent_hlist, hlist);
}
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