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Subject[patch] 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>
---
Index: git-tip/arch/x86/kernel/ds.c
===================================================================
--- git-tip.orig/arch/x86/kernel/ds.c 2009-03-17 12:26:07.000000000 +0100
+++ git-tip/arch/x86/kernel/ds.c 2009-03-17 13:30:09.000000000 +0100
@@ -255,8 +255,13 @@ static inline struct ds_context *ds_get_
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
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(stru
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;
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