Messages in this thread | | | Date | Tue, 12 May 2015 21:34:52 +0530 | From | Hemant Kumar <> | Subject | Re: [PATCH v3 1/2] perf/kvm: Port perf kvm to powerpc |
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Hi Scott,
On 05/12/2015 03:38 AM, Scott Wood wrote: > On Fri, 2015-05-08 at 06:37 +0530, Hemant Kumar wrote: >> From: Srikar Dronamraju <srikar@linux.vnet.ibm.com> >> >> perf kvm can be used to analyze guest exit reasons. This support already >> exists in x86. Hence, porting it to powerpc. >> >> - To trace KVM events : >> perf kvm stat record >> If many guests are running, we can track for a specific guest by using >> --pid as in : perf kvm stat record --pid <pid> >> >> - To see the results : >> perf kvm stat report >> >> The result shows the number of exits (from the guest context to >> host/hypervisor context) grouped by their respective exit reasons with >> their frequency. >> >> This patch makes use of the guest exit reasons available in >> "trace_book3s.h". It records on two already available tracepoints : >> "kvm_hv:kvm_guest_exit" and "kvm_hv:kvm_guest_enter". >> >> Note : This patch has a dependency on the patch "kvm/powerpc: Export >> kvm exit reasons" which exports the KVM exit reasons through the uapi. >> >> Here is a sample o/p: >> # pgrep qemu >> 19378 >> 60515 >> >> 2 Guests are running on the host. >> >> # perf kvm stat record -a >> ^C[ perf record: Woken up 1 times to write data ] >> [ perf record: Captured and wrote 4.153 MB perf.data.guest (39624 samples) ] >> >> # perf kvm stat report -p 60515 >> Analyze events for pid(s) 60515, all VCPUs: >> >> VM-EXIT Samples Samples% Time% Min Time Max Time Avg time >> >> H_DATA_STORAGE 5006 35.30% 0.13% 1.94us 49.46us 12.37us ( +- 0.52% ) >> HV_DECREMENTER 4457 31.43% 0.02% 0.72us 16.14us 1.91us ( +- 0.96% ) >> SYSCALL 2690 18.97% 0.10% 2.84us 528.24us 18.29us ( +- 3.75% ) >> RETURN_TO_HOST 1789 12.61% 99.76% 1.58us 672791.91us 27470.23us ( +- 3.00% ) >> EXTERNAL 240 1.69% 0.00% 0.69us 10.67us 1.33us ( +- 5.34% ) >> >> Total Samples:14182, Total events handled time:49264158.30us. >> >> Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> >> Signed-off-by: Hemant Kumar <hemant@linux.vnet.ibm.com> >> --- >> Patch has a dependency on : https://patchwork.ozlabs.org/patch/469839/ >> which exports the exit reasons to perf through uapi. >> >> Changes: >> - Original series split into two patchsets now : perf and powerpc >> side changes. >> >> arch/powerpc/include/uapi/asm/kvm_perf.h | 15 +++++++++++++++ >> tools/perf/arch/powerpc/Makefile | 1 + >> tools/perf/arch/powerpc/util/Build | 1 + >> tools/perf/arch/powerpc/util/kvm-stat.c | 33 ++++++++++++++++++++++++++++++++ >> 4 files changed, 50 insertions(+) >> create mode 100644 arch/powerpc/include/uapi/asm/kvm_perf.h >> create mode 100644 tools/perf/arch/powerpc/util/kvm-stat.c >> >> diff --git a/arch/powerpc/include/uapi/asm/kvm_perf.h b/arch/powerpc/include/uapi/asm/kvm_perf.h >> new file mode 100644 >> index 0000000..30fa670 >> --- /dev/null >> +++ b/arch/powerpc/include/uapi/asm/kvm_perf.h >> @@ -0,0 +1,15 @@ >> +#ifndef _ASM_POWERPC_KVM_PERF_H >> +#define _ASM_POWERPC_KVM_PERF_H >> + >> +#include <asm/trace_book3s.h> >> +#include <asm/kvm.h> >> + >> +#define DECODE_STR_LEN 20 >> + >> +#define VCPU_ID "vcpu_id" >> + >> +#define KVM_ENTRY_TRACE "kvm_hv:kvm_guest_enter" >> +#define KVM_EXIT_TRACE "kvm_hv:kvm_guest_exit" >> +#define KVM_EXIT_REASON "trap" >> + >> +#endif /* _ASM_POWERPC_KVM_PERF_H */ > Please make sure that anything book3s-specific is named that way.
Are you suggesting to name it to something like _ASM_POWERPC_BOOK3S_PERF_H ?
> And shouldn't this be part of the arch/powerpc-side patchset?
It should. Thanks, will move this to arch/powerpc side patchset.
>> diff --git a/tools/perf/arch/powerpc/Makefile b/tools/perf/arch/powerpc/Makefile >> index 7fbca17..21322e0 100644 >> --- a/tools/perf/arch/powerpc/Makefile >> +++ b/tools/perf/arch/powerpc/Makefile >> @@ -1,3 +1,4 @@ >> ifndef NO_DWARF >> PERF_HAVE_DWARF_REGS := 1 >> endif >> +HAVE_KVM_STAT_SUPPORT := 1 > Does this stuff fail gracefully if used on a PPC target that doesn't > support this?
Yes, it does.
> -Scott > > > _______________________________________________ > Linuxppc-dev mailing list > Linuxppc-dev@lists.ozlabs.org > https://lists.ozlabs.org/listinfo/linuxppc-dev
-- Thanks, Hemant Kumar
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