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perf arm-spe: Add snapshot mode support 

This patch enables 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>
Reviewed-by: Leo Yan <leo.yan@linaro.org>
Signed-off-by: German Gomez <german.gomez@arm.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20211109163009.92072-2-german.gomez@arm.com
Tested-by: Leo Yan <leo.yan@linaro.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
German Gomez 2021-11-09 16:30:07 +00:00 committed by Arnaldo Carvalho de Melo
parent 9aba0adae8
commit 0901b56028
1 changed files with 130 additions and 0 deletions
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130
tools/perf/arch/arm64/util/arm-spe.c
View File

@ -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;