Messages in this thread | | | Date | Wed, 23 Jul 2014 11:34:08 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [PATCH 16/52] perf tools: Add ability to record the current tid for each cpu |
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Em Tue, Jul 22, 2014 at 04:17:25PM +0300, Adrian Hunter escreveu: > Add an array to struct machine to store > the current tid running on each cpu. > Add machine functions to get / set > the tid for a cpu. > > This will be used to determine the tid > when decoding a per-cpu Instruction Trace.
Most machines don't have MAX_NR_CPUS cpus, but then this per-machine struct cost will be suffered only by tools that use this new facility, so it wouldn't be fair at this point to ask you to use a growing array.
See tools/perf/builtin-trace.c trace__set_fd_pathname() to see how it does for a thread fd->pathname table learn't from either reading /proc/PID/fd/ or using 'perf probe' made vfs_getname wannabe-tracepoints.
But in general, try to avoid using these FOO_MAX_BAR things :-\
- Arnaldo
> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> > --- > tools/perf/util/machine.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++ > tools/perf/util/machine.h | 5 +++++ > 2 files changed, 51 insertions(+) > > diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c > index 04c17a7..34dd63f 100644 > --- a/tools/perf/util/machine.c > +++ b/tools/perf/util/machine.c > @@ -47,6 +47,8 @@ int machine__init(struct machine *machine, const char *root_dir, pid_t pid) > thread__set_comm(thread, comm, 0); > } > > + machine->current_tid = NULL; > + > return 0; > } > > @@ -106,6 +108,7 @@ void machine__exit(struct machine *machine) > dsos__delete(&machine->user_dsos); > dsos__delete(&machine->kernel_dsos); > zfree(&machine->root_dir); > + zfree(&machine->current_tid); > } > > void machine__delete(struct machine *machine) > @@ -1532,3 +1535,46 @@ int machine__get_kernel_start(struct machine *machine) > } > return err; > } > + > +pid_t machine__get_current_tid(struct machine *machine, int cpu) > +{ > + if (cpu < 0 || cpu >= MAX_NR_CPUS || !machine->current_tid) > + return -1; > + > + return machine->current_tid[cpu]; > +} > + > +int machine__set_current_tid(struct machine *machine, int cpu, pid_t pid, > + pid_t tid) > +{ > + struct thread *thread; > + > + if (cpu < 0) > + return -EINVAL; > + > + if (!machine->current_tid) { > + int i; > + > + machine->current_tid = calloc(MAX_NR_CPUS, sizeof(pid_t)); > + if (!machine->current_tid) > + return -ENOMEM; > + for (i = 0; i < MAX_NR_CPUS; i++) > + machine->current_tid[i] = -1; > + } > + > + if (cpu >= MAX_NR_CPUS) { > + pr_err("Requested CPU %d too large. ", cpu); > + pr_err("Consider raising MAX_NR_CPUS\n"); > + return -EINVAL; > + } > + > + machine->current_tid[cpu] = tid; > + > + thread = machine__findnew_thread(machine, pid, tid); > + if (!thread) > + return -ENOMEM; > + > + thread->cpu = cpu; > + > + return 0; > +} > diff --git a/tools/perf/util/machine.h b/tools/perf/util/machine.h > index be97021..6442d65 100644 > --- a/tools/perf/util/machine.h > +++ b/tools/perf/util/machine.h > @@ -35,6 +35,7 @@ struct machine { > struct map *vmlinux_maps[MAP__NR_TYPES]; > u64 kernel_start; > symbol_filter_t symbol_filter; > + pid_t *current_tid; > }; > > static inline > @@ -212,4 +213,8 @@ int machine__synthesize_threads(struct machine *machine, struct target *target, > perf_event__process, data_mmap); > } > > +pid_t machine__get_current_tid(struct machine *machine, int cpu); > +int machine__set_current_tid(struct machine *machine, int cpu, pid_t pid, > + pid_t tid); > + > #endif /* __PERF_MACHINE_H */ > -- > 1.8.3.2
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