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authorPaul Mackerras <paulus@samba.org>2010-03-18 16:05:13 +1100
committerIngo Molnar <mingo@elte.hu>2010-03-18 06:48:29 +0100
commit9eff26ea48bfbe2885b158742a7512a097ec911b (patch)
treea914f959b78bdf4ee9eca897a743d727c27faf4f /arch/powerpc/include/asm
parentperf top: Add missing initialization to zero (diff)
downloadlinux-dev-9eff26ea48bfbe2885b158742a7512a097ec911b.tar.xz
linux-dev-9eff26ea48bfbe2885b158742a7512a097ec911b.zip
powerpc/perf_events: Fix call-graph recording, add perf_arch_fetch_caller_regs
This implements a powerpc version of perf_arch_fetch_caller_regs to get correct call-graphs. It's implemented in assembly because that way we can be sure there isn't a stack frame for perf_arch_fetch_caller_regs. If it was in C, gcc might or might not create a stack frame for it, which would affect the number of levels we have to skip. With this, we see results from perf record -e lock:lock_acquire like this: # Samples: 24878 # # Overhead Command Shared Object Symbol # ........ .............. ................. ...... # 14.99% perf [kernel.kallsyms] [k] ._raw_spin_lock | --- ._raw_spin_lock | |--25.00%-- .alloc_fd | (nil) | | | |--50.00%-- .anon_inode_getfd | | .sys_perf_event_open | | syscall_exit | | syscall | | create_counter | | __cmd_record | | run_builtin | | main | | 0xfd2e704 | | 0xfd2e8c0 | | (nil) ... etc. Signed-off-by: Paul Mackerras <paulus@samba.org> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: anton@samba.org Cc: linuxppc-dev@ozlabs.org Cc: Peter Zijlstra <peterz@infradead.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <20100318050513.GA6575@drongo> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/powerpc/include/asm')
-rw-r--r--arch/powerpc/include/asm/asm-compat.h2
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/asm-compat.h b/arch/powerpc/include/asm/asm-compat.h
index c1b475a941eb..a9b91ed3d4b9 100644
--- a/arch/powerpc/include/asm/asm-compat.h
+++ b/arch/powerpc/include/asm/asm-compat.h
@@ -28,6 +28,7 @@
#define PPC_LLARX(t, a, b, eh) PPC_LDARX(t, a, b, eh)
#define PPC_STLCX stringify_in_c(stdcx.)
#define PPC_CNTLZL stringify_in_c(cntlzd)
+#define PPC_LR_STKOFF 16
/* Move to CR, single-entry optimized version. Only available
* on POWER4 and later.
@@ -51,6 +52,7 @@
#define PPC_STLCX stringify_in_c(stwcx.)
#define PPC_CNTLZL stringify_in_c(cntlzw)
#define PPC_MTOCRF stringify_in_c(mtcrf)
+#define PPC_LR_STKOFF 4
#endif