Messages in this thread | | | From | Ze Gao <> | Date | Thu, 3 Aug 2023 20:37:04 +0800 | Subject | Re: [RFC PATCH v6 2/5] perf sched: reorganize sched-out task state report code |
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Hi Steven,
THIS IS THE NEW CHANGELOG FOR THIS PATCH:
perf sched: reorganize sched-out task state report code
Passing around the task state reported by tracepoint as an integer creates dependencies both on the task state macros and TASK_STATE_TO_CHAR_STR.
Actually we can simplify this by computing the state based on TASK_STATE_TO_CHAR_STR and then pass the result as a 'char', which saves us from using these macros anymore. So we can remove them for good.
Note that sched_out_state() is basically doing the same thing as task_state_char(), so combine them into one and provide an intended helper get_task_prev_state() for extracting task state from perf record.
IOW, this patch does not introduce any functional changes. mainly for housekeeping.
Signed-off-by: Ze Gao <zegao@tencent.com>
Suggestions?
Regards, Ze
On Thu, Aug 3, 2023 at 5:10 PM Steven Rostedt <rostedt@goodmis.org> wrote: > > On Thu, 3 Aug 2023 04:33:49 -0400 > Ze Gao <zegao2021@gmail.com> wrote: > > > Mainly does housekeeping work and not introduce any > > functional change. > > This change log doesn't explain at all why this patch is needed, let alone > what it is even doing. > > -- Steve > > > > > > Signed-off-by: Ze Gao <zegao@tencent.com> > > --- > > tools/perf/builtin-sched.c | 59 +++++++++++++++++--------------------- > > 1 file changed, 26 insertions(+), 33 deletions(-) > > > > diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c > > index 8dc8f071721c..5042874ba204 100644 > > --- a/tools/perf/builtin-sched.c > > +++ b/tools/perf/builtin-sched.c > > @@ -94,11 +94,6 @@ struct sched_atom { > > > > #define TASK_STATE_TO_CHAR_STR "RSDTtXZPI" > > > > -/* task state bitmask, copied from include/linux/sched.h */ > > -#define TASK_RUNNING 0 > > -#define TASK_INTERRUPTIBLE 1 > > -#define TASK_UNINTERRUPTIBLE 2 > > - > > enum thread_state { > > THREAD_SLEEPING = 0, > > THREAD_WAIT_CPU, > > @@ -255,7 +250,7 @@ struct thread_runtime { > > u64 total_preempt_time; > > u64 total_delay_time; > > > > - int last_state; > > + char last_state; > > > > char shortname[3]; > > bool comm_changed; > > @@ -425,7 +420,7 @@ static void add_sched_event_wakeup(struct perf_sched *sched, struct task_desc *t > > } > > > > static void add_sched_event_sleep(struct perf_sched *sched, struct task_desc *task, > > - u64 timestamp, u64 task_state __maybe_unused) > > + u64 timestamp, char task_state __maybe_unused) > > { > > struct sched_atom *event = get_new_event(task, timestamp); > > > > @@ -840,6 +835,22 @@ replay_wakeup_event(struct perf_sched *sched, > > return 0; > > } > > > > +static inline char task_state_char(int state) > > +{ > > + static const char state_to_char[] = "RSDTtXZPI"; > > + unsigned int bit = state ? ffs(state) : 0; > > + > > + return bit < sizeof(state_to_char) - 1 ? state_to_char[bit] : '?'; > > +} > > + > > +static inline char get_task_prev_state(struct evsel *evsel, > > + struct perf_sample *sample) > > +{ > > + const int prev_state = evsel__intval(evsel, sample, "prev_state"); > > + > > + return task_state_char(prev_state); > > +} > > + > > static int replay_switch_event(struct perf_sched *sched, > > struct evsel *evsel, > > struct perf_sample *sample, > > @@ -849,7 +860,7 @@ static int replay_switch_event(struct perf_sched *sched, > > *next_comm = evsel__strval(evsel, sample, "next_comm"); > > const u32 prev_pid = evsel__intval(evsel, sample, "prev_pid"), > > next_pid = evsel__intval(evsel, sample, "next_pid"); > > - const u64 prev_state = evsel__intval(evsel, sample, "prev_state"); > > + const char prev_state = get_task_prev_state(evsel, sample); > > struct task_desc *prev, __maybe_unused *next; > > u64 timestamp0, timestamp = sample->time; > > int cpu = sample->cpu; > > @@ -1039,12 +1050,6 @@ static int thread_atoms_insert(struct perf_sched *sched, struct thread *thread) > > return 0; > > } > > > > -static char sched_out_state(u64 prev_state) > > -{ > > - const char *str = TASK_STATE_TO_CHAR_STR; > > - > > - return str[prev_state]; > > -} > > > > static int > > add_sched_out_event(struct work_atoms *atoms, > > @@ -1121,7 +1126,7 @@ static int latency_switch_event(struct perf_sched *sched, > > { > > const u32 prev_pid = evsel__intval(evsel, sample, "prev_pid"), > > next_pid = evsel__intval(evsel, sample, "next_pid"); > > - const u64 prev_state = evsel__intval(evsel, sample, "prev_state"); > > + const char prev_state = get_task_prev_state(evsel, sample); > > struct work_atoms *out_events, *in_events; > > struct thread *sched_out, *sched_in; > > u64 timestamp0, timestamp = sample->time; > > @@ -1157,7 +1162,7 @@ static int latency_switch_event(struct perf_sched *sched, > > goto out_put; > > } > > } > > - if (add_sched_out_event(out_events, sched_out_state(prev_state), timestamp)) > > + if (add_sched_out_event(out_events, prev_state, timestamp)) > > return -1; > > > > in_events = thread_atoms_search(&sched->atom_root, sched_in, &sched->cmp_pid); > > @@ -2022,24 +2027,12 @@ static void timehist_header(struct perf_sched *sched) > > printf("\n"); > > } > > > > -static char task_state_char(struct thread *thread, int state) > > -{ > > - static const char state_to_char[] = TASK_STATE_TO_CHAR_STR; > > - unsigned bit = state ? ffs(state) : 0; > > - > > - /* 'I' for idle */ > > - if (thread__tid(thread) == 0) > > - return 'I'; > > - > > - return bit < sizeof(state_to_char) - 1 ? state_to_char[bit] : '?'; > > -} > > - > > static void timehist_print_sample(struct perf_sched *sched, > > struct evsel *evsel, > > struct perf_sample *sample, > > struct addr_location *al, > > struct thread *thread, > > - u64 t, int state) > > + u64 t, char state) > > { > > struct thread_runtime *tr = thread__priv(thread); > > const char *next_comm = evsel__strval(evsel, sample, "next_comm"); > > @@ -2080,7 +2073,7 @@ static void timehist_print_sample(struct perf_sched *sched, > > print_sched_time(tr->dt_run, 6); > > > > if (sched->show_state) > > - printf(" %5c ", task_state_char(thread, state)); > > + printf(" %5c ", thread->tid == 0 ? 'I' : state); > > > > if (sched->show_next) { > > snprintf(nstr, sizeof(nstr), "next: %s[%d]", next_comm, next_pid); > > @@ -2152,9 +2145,9 @@ static void timehist_update_runtime_stats(struct thread_runtime *r, > > else if (r->last_time) { > > u64 dt_wait = tprev - r->last_time; > > > > - if (r->last_state == TASK_RUNNING) > > + if (r->last_state == 'R') > > r->dt_preempt = dt_wait; > > - else if (r->last_state == TASK_UNINTERRUPTIBLE) > > + else if (r->last_state == 'D') > > r->dt_iowait = dt_wait; > > else > > r->dt_sleep = dt_wait; > > @@ -2579,7 +2572,7 @@ static int timehist_sched_change_event(struct perf_tool *tool, > > struct thread_runtime *tr = NULL; > > u64 tprev, t = sample->time; > > int rc = 0; > > - int state = evsel__intval(evsel, sample, "prev_state"); > > + const char state = get_task_prev_state(evsel, sample); > > > > addr_location__init(&al); > > if (machine__resolve(machine, &al, sample) < 0) { >
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