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authorMarkus Metzger <markus.t.metzger@intel.com>2009-03-18 19:27:00 +0100
committerIngo Molnar <mingo@elte.hu>2009-03-19 14:02:47 +0100
commitc78a3956b982418186e40978a51636a2b43221bc (patch)
treeedc09b263a4bfc8143e4161d93cb3b7251f6a1c6 /arch
parent79258a354e0c69be94ae2871809a195bf4a647b1 (diff)
x86, bts: use atomic memory allocation
Ds_request_bts() needs to allocate memory. It uses GFP_KERNEL. Hw-branch-tracer calls ds_request_bts() within on_each_cpu(). Use atomic memory allocation to allow it to be used in that context. Signed-off-by: Markus Metzger <markus.t.metzger@intel.com> LKML-Reference: <20090318192700.A6038@sedona.ch.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kernel/ds.c21
1 files changed, 17 insertions, 4 deletions
diff --git a/arch/x86/kernel/ds.c b/arch/x86/kernel/ds.c
index 5fd53333c1d..b1d6e1f502f 100644
--- a/arch/x86/kernel/ds.c
+++ b/arch/x86/kernel/ds.c
@@ -255,8 +255,13 @@ static inline struct ds_context *ds_get_context(struct task_struct *task)
struct ds_context *new_context = NULL;
unsigned long irq;
- /* Chances are small that we already have a context. */
- new_context = kzalloc(sizeof(*new_context), GFP_KERNEL);
+ /*
+ * Chances are small that we already have a context.
+ *
+ * Contexts for per-cpu tracing are allocated using
+ * smp_call_function(). We must not sleep.
+ */
+ new_context = kzalloc(sizeof(*new_context), GFP_ATOMIC);
if (!new_context)
return NULL;
@@ -662,8 +667,12 @@ struct bts_tracer *ds_request_bts(struct task_struct *task,
if (ovfl)
goto out;
+ /*
+ * Per-cpu tracing is typically requested using smp_call_function().
+ * We must not sleep.
+ */
error = -ENOMEM;
- tracer = kzalloc(sizeof(*tracer), GFP_KERNEL);
+ tracer = kzalloc(sizeof(*tracer), GFP_ATOMIC);
if (!tracer)
goto out;
tracer->ovfl = ovfl;
@@ -722,8 +731,12 @@ struct pebs_tracer *ds_request_pebs(struct task_struct *task,
if (ovfl)
goto out;
+ /*
+ * Per-cpu tracing is typically requested using smp_call_function().
+ * We must not sleep.
+ */
error = -ENOMEM;
- tracer = kzalloc(sizeof(*tracer), GFP_KERNEL);
+ tracer = kzalloc(sizeof(*tracer), GFP_ATOMIC);
if (!tracer)
goto out;
tracer->ovfl = ovfl;