Commit-ID: 24cc12b17679f8e9046746f92fd377f589efc163 Gitweb: http://git.kernel.org/tip/24cc12b17679f8e9046746f92fd377f589efc163 Author: Takao Indoh <[email protected]> AuthorDate: Wed, 4 Nov 2015 14:22:32 +0900 Committer: Ingo Molnar <[email protected]> CommitDate: Mon, 23 Nov 2015 09:58:26 +0100
perf/x86/intel/pt: Add interface to stop Intel PT logging This patch add a function for external components to stop Intel PT. Basically this function is used when kernel panic occurs. When it is called, the intel_pt driver disables Intel PT and saves its registers using pt_event_stop(), which is also used by pmu.stop handler. This function stops Intel PT on the CPU where it is working, therefore users of it need to call it for each CPU to stop all logging. Signed-off-by: Takao Indoh <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Alexander Shishkin<[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: H.Peter Anvin <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Mike Galbraith <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Stephane Eranian <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Vince Weaver <[email protected]> Cc: Vivek Goyal <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> --- arch/x86/include/asm/intel_pt.h | 10 ++++++++++ arch/x86/kernel/cpu/perf_event_intel_pt.c | 9 +++++++++ 2 files changed, 19 insertions(+) diff --git a/arch/x86/include/asm/intel_pt.h b/arch/x86/include/asm/intel_pt.h new file mode 100644 index 0000000..e1a4117 --- /dev/null +++ b/arch/x86/include/asm/intel_pt.h @@ -0,0 +1,10 @@ +#ifndef _ASM_X86_INTEL_PT_H +#define _ASM_X86_INTEL_PT_H + +#if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_CPU_SUP_INTEL) +void cpu_emergency_stop_pt(void); +#else +static inline void cpu_emergency_stop_pt(void) {} +#endif + +#endif /* _ASM_X86_INTEL_PT_H */ diff --git a/arch/x86/kernel/cpu/perf_event_intel_pt.c b/arch/x86/kernel/cpu/perf_event_intel_pt.c index 868e119..c0bbd10 100644 --- a/arch/x86/kernel/cpu/perf_event_intel_pt.c +++ b/arch/x86/kernel/cpu/perf_event_intel_pt.c @@ -27,6 +27,7 @@ #include <asm/perf_event.h> #include <asm/insn.h> #include <asm/io.h> +#include <asm/intel_pt.h> #include "perf_event.h" #include "intel_pt.h" @@ -1122,6 +1123,14 @@ static int pt_event_init(struct perf_event *event) return 0; } +void cpu_emergency_stop_pt(void) +{ + struct pt *pt = this_cpu_ptr(&pt_ctx); + + if (pt->handle.event) + pt_event_stop(pt->handle.event, PERF_EF_UPDATE); +} + static __init int pt_init(void) { int ret, cpu, prior_warn = 0; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
