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author | 2020-04-29 18:07:48 +0300 | |
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committer | 2020-05-05 16:35:29 -0300 | |
commit | 3749e0bbdef24efbf1698bf0dbd9575fddb9ed22 (patch) | |
tree | dd1d179d4b110d997dfb1ed7761d5fb9bf795267 /tools/perf/util/thread-stack.c | |
parent | perf evsel: Add support for synthesized branch stack sample type (diff) | |
download | linux-3749e0bbdef24efbf1698bf0dbd9575fddb9ed22.tar.gz linux-3749e0bbdef24efbf1698bf0dbd9575fddb9ed22.tar.bz2 linux-3749e0bbdef24efbf1698bf0dbd9575fddb9ed22.zip |
perf thread-stack: Add thread_stack__br_sample_late()
Add a thread stack function to create a branch stack for hardware events
where the sample records get created some time after the event occurred.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/20200429150751.12570-7-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/util/thread-stack.c')
-rw-r--r-- | tools/perf/util/thread-stack.c | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/tools/perf/util/thread-stack.c b/tools/perf/util/thread-stack.c index 79698831b4b9..1b992bbba4e8 100644 --- a/tools/perf/util/thread-stack.c +++ b/tools/perf/util/thread-stack.c @@ -645,6 +645,110 @@ void thread_stack__br_sample(struct thread *thread, int cpu, } } +/* Start of user space branch entries */ +static bool us_start(struct branch_entry *be, u64 kernel_start, bool *start) +{ + if (!*start) + *start = be->to && be->to < kernel_start; + + return *start; +} + +/* + * Start of branch entries after the ip fell in between 2 branches, or user + * space branch entries. + */ +static bool ks_start(struct branch_entry *be, u64 sample_ip, u64 kernel_start, + bool *start, struct branch_entry *nb) +{ + if (!*start) { + *start = (nb && sample_ip >= be->to && sample_ip <= nb->from) || + be->from < kernel_start || + (be->to && be->to < kernel_start); + } + + return *start; +} + +/* + * Hardware sample records, created some time after the event occurred, need to + * have subsequent addresses removed from the branch stack. + */ +void thread_stack__br_sample_late(struct thread *thread, int cpu, + struct branch_stack *dst, unsigned int sz, + u64 ip, u64 kernel_start) +{ + struct thread_stack *ts = thread__stack(thread, cpu); + struct branch_entry *d, *s, *spos, *ssz; + struct branch_stack *src; + unsigned int nr = 0; + bool start = false; + + dst->nr = 0; + + if (!ts) + return; + + src = ts->br_stack_rb; + if (!src->nr) + return; + + spos = &src->entries[ts->br_stack_pos]; + ssz = &src->entries[ts->br_stack_sz]; + + d = &dst->entries[0]; + s = spos; + + if (ip < kernel_start) { + /* + * User space sample: start copying branch entries when the + * branch is in user space. + */ + for (s = spos; s < ssz && nr < sz; s++) { + if (us_start(s, kernel_start, &start)) { + *d++ = *s; + nr += 1; + } + } + + if (src->nr >= ts->br_stack_sz) { + for (s = &src->entries[0]; s < spos && nr < sz; s++) { + if (us_start(s, kernel_start, &start)) { + *d++ = *s; + nr += 1; + } + } + } + } else { + struct branch_entry *nb = NULL; + + /* + * Kernel space sample: start copying branch entries when the ip + * falls in between 2 branches (or the branch is in user space + * because then the start must have been missed). + */ + for (s = spos; s < ssz && nr < sz; s++) { + if (ks_start(s, ip, kernel_start, &start, nb)) { + *d++ = *s; + nr += 1; + } + nb = s; + } + + if (src->nr >= ts->br_stack_sz) { + for (s = &src->entries[0]; s < spos && nr < sz; s++) { + if (ks_start(s, ip, kernel_start, &start, nb)) { + *d++ = *s; + nr += 1; + } + nb = s; + } + } + } + + dst->nr = nr; +} + struct call_return_processor * call_return_processor__new(int (*process)(struct call_return *cr, u64 *parent_db_id, void *data), void *data) |