BTS data can be used in process core dumps. This patch implements itrace core dump related hooks that will configure and output BTS traces into a core file.
Signed-off-by: Alexander Shishkin <[email protected]> --- arch/x86/kernel/cpu/perf_event_intel_bts.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/arch/x86/kernel/cpu/perf_event_intel_bts.c b/arch/x86/kernel/cpu/perf_event_intel_bts.c index 0a08969..20a19b2 100644 --- a/arch/x86/kernel/cpu/perf_event_intel_bts.c +++ b/arch/x86/kernel/cpu/perf_event_intel_bts.c @@ -436,6 +436,26 @@ static void bts_event_read(struct perf_event *event) { } +static size_t bts_trace_core_size(struct perf_event *event) +{ + return 0; +} + +static void bts_trace_core_output(struct coredump_params *cprm, + struct perf_event *event, + unsigned long len) +{ + struct bts_buffer *buf = itrace_event_get_priv(event); + u64 head = local64_read(&buf->head); + + if (head < len) { + dump_emit(cprm, buf->buf + head, buf->real_size - head); + dump_emit(cprm, buf->buf, len - buf->real_size + head); + } else + dump_emit(cprm, buf->buf + head - len, len); + itrace_event_put(event); +} + static __init int bts_init(void) { int ret, cpu; @@ -459,6 +479,8 @@ static __init int bts_init(void) bts_pmu.pmu.read = bts_event_read; bts_pmu.alloc_buffer = bts_buffer_itrace_alloc; bts_pmu.free_buffer = bts_buffer_itrace_free; + bts_pmu.core_size = bts_trace_core_size; + bts_pmu.core_output = bts_trace_core_output; bts_pmu.name = "intel_bts"; ret = itrace_pmu_register(&bts_pmu); -- 1.8.5.2 -- 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/
