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>
diff --git a/arch/x86/kernel/ds.c b/arch/x86/kernel/ds.c
index 5fd5333..b1d6e1f 100644
--- a/arch/x86/kernel/ds.c
+++ b/arch/x86/kernel/ds.c
@@ -255,8 +255,13 @@
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 @@
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 @@
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;