perf_counter: Make callchain samples extensible
Before exposing upstream tools to a callchain-samples ABI, tidy it
up to make it more extensible in the future:
Use markers in the IP chain to denote context, use (u64)-1..-4095 range
for these context markers because we use them for ERR_PTR(), so these
addresses are unlikely to be mapped.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/include/linux/perf_counter.h b/include/linux/perf_counter.h
index 0765e8e..e7e7e02 100644
--- a/include/linux/perf_counter.h
+++ b/include/linux/perf_counter.h
@@ -343,23 +343,22 @@
* { u64 nr;
* { u64 id, val; } cnt[nr]; } && PERF_SAMPLE_GROUP
*
- * { u16 nr,
- * hv,
- * kernel,
- * user;
+ * { u64 nr,
* u64 ips[nr]; } && PERF_SAMPLE_CALLCHAIN
* };
*/
};
-#define MAX_STACK_DEPTH 255
+enum perf_callchain_context {
+ PERF_CONTEXT_HV = (__u64)-32,
+ PERF_CONTEXT_KERNEL = (__u64)-128,
+ PERF_CONTEXT_USER = (__u64)-512,
-struct perf_callchain_entry {
- __u16 nr;
- __u16 hv;
- __u16 kernel;
- __u16 user;
- __u64 ip[MAX_STACK_DEPTH];
+ PERF_CONTEXT_GUEST = (__u64)-2048,
+ PERF_CONTEXT_GUEST_KERNEL = (__u64)-2176,
+ PERF_CONTEXT_GUEST_USER = (__u64)-2560,
+
+ PERF_CONTEXT_MAX = (__u64)-4095,
};
#ifdef __KERNEL__
@@ -381,6 +380,13 @@
#include <linux/pid_namespace.h>
#include <asm/atomic.h>
+#define PERF_MAX_STACK_DEPTH 255
+
+struct perf_callchain_entry {
+ __u64 nr;
+ __u64 ip[PERF_MAX_STACK_DEPTH];
+};
+
struct task_struct;
/**