This patch enabled support for snapshot mode of arm_spe events, including the implementation of the necessary callbacks (excluding find_snapshot, which is to be included in a followup commit).
Reviewed-by: James Clark james.clark@arm.com Signed-off-by: German Gomez german.gomez@arm.com --- tools/perf/arch/arm64/util/arm-spe.c | 130 +++++++++++++++++++++++++++ 1 file changed, 130 insertions(+)
diff --git a/tools/perf/arch/arm64/util/arm-spe.c b/tools/perf/arch/arm64/util/arm-spe.c index a4420d4df503..f8b03d164b42 100644 --- a/tools/perf/arch/arm64/util/arm-spe.c +++ b/tools/perf/arch/arm64/util/arm-spe.c @@ -84,6 +84,55 @@ static int arm_spe_info_fill(struct auxtrace_record *itr, return 0; }
+static void +arm_spe_snapshot_resolve_auxtrace_defaults(struct record_opts *opts, + bool privileged) +{ + /* + * The default snapshot size is the auxtrace mmap size. If neither auxtrace mmap size nor + * snapshot size is specified, then the default is 4MiB for privileged users, 128KiB for + * unprivileged users. + * + * The default auxtrace mmap size is 4MiB/page_size for privileged users, 128KiB for + * unprivileged users. If an unprivileged user does not specify mmap pages, the mmap pages + * will be reduced from the default 512KiB/page_size to 256KiB/page_size, otherwise the + * user is likely to get an error as they exceed their mlock limmit. + */ + + /* + * No size were given to '-S' or '-m,', so go with the default + */ + if (!opts->auxtrace_snapshot_size && !opts->auxtrace_mmap_pages) { + if (privileged) { + opts->auxtrace_mmap_pages = MiB(4) / page_size; + } else { + opts->auxtrace_mmap_pages = KiB(128) / page_size; + if (opts->mmap_pages == UINT_MAX) + opts->mmap_pages = KiB(256) / page_size; + } + } else if (!opts->auxtrace_mmap_pages && !privileged && opts->mmap_pages == UINT_MAX) { + opts->mmap_pages = KiB(256) / page_size; + } + + /* + * '-m,xyz' was specified but no snapshot size, so make the snapshot size as big as the + * auxtrace mmap area. + */ + if (!opts->auxtrace_snapshot_size) + opts->auxtrace_snapshot_size = opts->auxtrace_mmap_pages * (size_t)page_size; + + /* + * '-Sxyz' was specified but no auxtrace mmap area, so make the auxtrace mmap area big + * enough to fit the requested snapshot size. + */ + if (!opts->auxtrace_mmap_pages) { + size_t sz = opts->auxtrace_snapshot_size; + + sz = round_up(sz, page_size) / page_size; + opts->auxtrace_mmap_pages = roundup_pow_of_two(sz); + } +} + static int arm_spe_recording_options(struct auxtrace_record *itr, struct evlist *evlist, struct record_opts *opts) @@ -115,6 +164,36 @@ static int arm_spe_recording_options(struct auxtrace_record *itr, if (!opts->full_auxtrace) return 0;
+ /* + * we are in snapshot mode. + */ + if (opts->auxtrace_snapshot_mode) { + /* + * Command arguments '-Sxyz' and/or '-m,xyz' are missing, so fill those in with + * default values. + */ + if (!opts->auxtrace_snapshot_size || !opts->auxtrace_mmap_pages) + arm_spe_snapshot_resolve_auxtrace_defaults(opts, privileged); + + /* + * Snapshot size can't be bigger than the auxtrace area. + */ + if (opts->auxtrace_snapshot_size > opts->auxtrace_mmap_pages * (size_t)page_size) { + pr_err("Snapshot size %zu must not be greater than AUX area tracing mmap size %zu\n", + opts->auxtrace_snapshot_size, + opts->auxtrace_mmap_pages * (size_t)page_size); + return -EINVAL; + } + + /* + * Something went wrong somewhere - this shouldn't happen. + */ + if (!opts->auxtrace_snapshot_size || !opts->auxtrace_mmap_pages) { + pr_err("Failed to calculate default snapshot size and/or AUX area tracing mmap pages\n"); + return -EINVAL; + } + } + /* We are in full trace mode but '-m,xyz' wasn't specified */ if (!opts->auxtrace_mmap_pages) { if (privileged) { @@ -138,6 +217,9 @@ static int arm_spe_recording_options(struct auxtrace_record *itr, } }
+ if (opts->auxtrace_snapshot_mode) + pr_debug2("%sx snapshot size: %zu\n", ARM_SPE_PMU_NAME, + opts->auxtrace_snapshot_size);
/* * To obtain the auxtrace buffer file descriptor, the auxtrace event @@ -172,6 +254,51 @@ static int arm_spe_recording_options(struct auxtrace_record *itr, return 0; }
+static int arm_spe_parse_snapshot_options(struct auxtrace_record *itr __maybe_unused, + struct record_opts *opts, + const char *str) +{ + unsigned long long snapshot_size = 0; + char *endptr; + + if (str) { + snapshot_size = strtoull(str, &endptr, 0); + if (*endptr || snapshot_size > SIZE_MAX) + return -1; + } + + opts->auxtrace_snapshot_mode = true; + opts->auxtrace_snapshot_size = snapshot_size; + + return 0; +} + +static int arm_spe_snapshot_start(struct auxtrace_record *itr) +{ + struct arm_spe_recording *ptr = + container_of(itr, struct arm_spe_recording, itr); + struct evsel *evsel; + + evlist__for_each_entry(ptr->evlist, evsel) { + if (evsel->core.attr.type == ptr->arm_spe_pmu->type) + return evsel__disable(evsel); + } + return -EINVAL; +} + +static int arm_spe_snapshot_finish(struct auxtrace_record *itr) +{ + struct arm_spe_recording *ptr = + container_of(itr, struct arm_spe_recording, itr); + struct evsel *evsel; + + evlist__for_each_entry(ptr->evlist, evsel) { + if (evsel->core.attr.type == ptr->arm_spe_pmu->type) + return evsel__enable(evsel); + } + return -EINVAL; +} + static u64 arm_spe_reference(struct auxtrace_record *itr __maybe_unused) { struct timespec ts; @@ -207,6 +334,9 @@ struct auxtrace_record *arm_spe_recording_init(int *err,
sper->arm_spe_pmu = arm_spe_pmu; sper->itr.pmu = arm_spe_pmu; + sper->itr.snapshot_start = arm_spe_snapshot_start; + sper->itr.snapshot_finish = arm_spe_snapshot_finish; + sper->itr.parse_snapshot_options = arm_spe_parse_snapshot_options; sper->itr.recording_options = arm_spe_recording_options; sper->itr.info_priv_size = arm_spe_info_priv_size; sper->itr.info_fill = arm_spe_info_fill;