Commit-ID: c7b4f15ff79b539fed4c382e52e988548081bc9d Gitweb: https://git.kernel.org/tip/c7b4f15ff79b539fed4c382e52e988548081bc9d Author: Adrian Hunter <adrian.hun...@intel.com> AuthorDate: Fri, 12 Apr 2019 14:38:29 +0300 Committer: Arnaldo Carvalho de Melo <a...@redhat.com> CommitDate: Tue, 28 May 2019 18:37:45 -0300
perf intel-pt: Improve sync_switch by processing PERF_RECORD_SWITCH* in events sync_switch is a facility to synchronize decoding more closely with the point in the kernel when the context actually switched. Improve it by processing "context switch in" events. Signed-off-by: Adrian Hunter <adrian.hun...@intel.com> Cc: Jiri Olsa <jo...@redhat.com> Link: http://lkml.kernel.org/r/20190412113830.4126-8-adrian.hun...@intel.com Signed-off-by: Arnaldo Carvalho de Melo <a...@redhat.com> --- tools/perf/util/intel-pt.c | 40 +++++++++++++++++++++++++++++++++++++++- 1 file changed, 39 insertions(+), 1 deletion(-) diff --git a/tools/perf/util/intel-pt.c b/tools/perf/util/intel-pt.c index 03b1da6d1da4..6aaba1146fc8 100644 --- a/tools/perf/util/intel-pt.c +++ b/tools/perf/util/intel-pt.c @@ -1914,6 +1914,44 @@ static int intel_pt_process_switch(struct intel_pt *pt, return machine__set_current_tid(pt->machine, cpu, -1, tid); } +static int intel_pt_context_switch_in(struct intel_pt *pt, + struct perf_sample *sample) +{ + pid_t pid = sample->pid; + pid_t tid = sample->tid; + int cpu = sample->cpu; + + if (pt->sync_switch) { + struct intel_pt_queue *ptq; + + ptq = intel_pt_cpu_to_ptq(pt, cpu); + if (ptq && ptq->sync_switch) { + ptq->next_tid = -1; + switch (ptq->switch_state) { + case INTEL_PT_SS_NOT_TRACING: + case INTEL_PT_SS_UNKNOWN: + case INTEL_PT_SS_TRACING: + break; + case INTEL_PT_SS_EXPECTING_SWITCH_EVENT: + case INTEL_PT_SS_EXPECTING_SWITCH_IP: + ptq->switch_state = INTEL_PT_SS_TRACING; + break; + default: + break; + } + } + } + + /* + * If the current tid has not been updated yet, ensure it is now that + * a "switch in" event has occurred. + */ + if (machine__get_current_tid(pt->machine, cpu) == tid) + return 0; + + return machine__set_current_tid(pt->machine, cpu, pid, tid); +} + static int intel_pt_context_switch(struct intel_pt *pt, union perf_event *event, struct perf_sample *sample) { @@ -1925,7 +1963,7 @@ static int intel_pt_context_switch(struct intel_pt *pt, union perf_event *event, if (pt->have_sched_switch == 3) { if (!out) - return 0; + return intel_pt_context_switch_in(pt, sample); if (event->header.type != PERF_RECORD_SWITCH_CPU_WIDE) { pr_err("Expecting CPU-wide context switch event\n"); return -EINVAL;
