Messages in this thread Patch in this message | | | Date | Fri, 26 Mar 2010 17:02:30 +1100 | From | Paul Mackerras <> | Subject | Re: [PATCH 0/7] perf updates and fixes |
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On Fri, Mar 26, 2010 at 02:52:35AM +0100, Frederic Weisbecker wrote:
> The series is not yet mergeable because it would break PowerPc > (hot regs snapshot API has been changed, and I don't know how > to update PowerPc for that). > > But if you're fine with the ideas, I can integrate the necessary > changes to fix this, and also separate fixes and updates.
The patch below adds the necessary stuff for powerpc. You could fold it into your "perf: Move perf_arch_fetch_caller_regs into a macro" patch, or keep it as a separate patch in the series (though that would make preserving bisectability more difficult).
There is a little difficulty in that you first create a 3-argument form of perf_arch_fetch_caller_regs and then remove one argument in a later patch, whereas my patch below just creates the 2-argument form. I'm sure you can resolve that one way or another.
The patch to add the old-style perf_arch_fetch_caller_regs for powerpc is sitting in the tip/perf/urgent branch but hasn't gone anywhere. I suppose we need to get Ingo to pull that branch into tip/perf/core and then include a revert patch in the series that switches to the new interface. Alternatively, if the urgent branch isn't append-only then we could disappear it (the urgent branch would need to be rewound by one commit).
Paul. ---------- [PATCH] perf/powerpc: Implement perf_arch_fetch_caller_regs for powerpc
This adds the ability to get a hot register snapshot for powerpc, enabling us to get meaningful call chains for tracepoints and context switch events.
Signed-off-by: Paul Mackerras <paulus@samba.org> --- arch/powerpc/include/asm/perf_event.h | 12 ++++++++++++ 1 file changed, 12 insertions(+)
diff --git a/arch/powerpc/include/asm/perf_event.h b/arch/powerpc/include/asm/perf_event.h index e6d4ce6..5c16b89 100644 --- a/arch/powerpc/include/asm/perf_event.h +++ b/arch/powerpc/include/asm/perf_event.h @@ -21,3 +21,15 @@ #ifdef CONFIG_FSL_EMB_PERF_EVENT #include <asm/perf_event_fsl_emb.h> #endif + +#ifdef CONFIG_PERF_EVENTS +#include <asm/ptrace.h> +#include <asm/reg.h> + +#define perf_arch_fetch_caller_regs(regs, __ip) \ + do { \ + (regs)->nip = __ip; \ + (regs)->gpr[1] = *(unsigned long *)__get_SP(); \ + asm volatile("mfmsr %0" : "=r" ((regs)->msr)); \ + } while (0) +#endif
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