[PATCH 5/5] perf stat: Enable --iiostat mode for x86 platforms

From: Alexander Antonov
Date: Thu Dec 10 2020 - 04:07:02 EST

This functionality is based on recently introduced sysfs attributes
for Intel® Xeon® Scalable processor family (code name Skylake-SP):
Commit bb42b3d39781 ("perf/x86/intel/uncore: Expose an Uncore unit to
IIO PMON mapping")

Mode is intended to provide four I/O performance metrics in MB per each
IIO stack:
- Inbound Read: I/O devices below IIO stack read from the host memory
- Inbound Write: I/O devices below IIO stack write to the host memory
- Outbound Read: CPU reads from I/O devices below IIO stack
- Outbound Write: CPU writes to I/O devices below IIO stack

Each metric requiries only one IIO event which increments at every 4B
transfer in corresponding direction. The formulas to compute metrics
are generic:
#EventCount * 4B / (1024 * 1024)

Signed-off-by: Alexander Antonov <alexander.antonov@xxxxxxxxxxxxxxx>
---
tools/perf/Documentation/perf-stat.txt | 31 +++
tools/perf/arch/x86/util/Build | 1 +
tools/perf/arch/x86/util/iiostat.c | 335 +++++++++++++++++++++++++
3 files changed, 367 insertions(+)

diff --git a/tools/perf/Documentation/perf-stat.txt b/tools/perf/Documentation/perf-stat.txt
index 5d4a673d7621..2c066f7e0681 100644
--- a/tools/perf/Documentation/perf-stat.txt
+++ b/tools/perf/Documentation/perf-stat.txt
@@ -121,6 +121,37 @@ to activate system-wide monitoring. Default is to count on all CPUs.
-A::
--no-aggr::
Do not aggregate counts across all monitored CPUs.
+--iiostat::
+Mode is intended to provide four I/O performance metrics per each IIO
+stack (PCIe root port):
+ --Inbound Read(MB) - I/O devices below IIO stack read from the host memory, in MB
+ --Inbound Write(MB) - I/O devices below IIO stack write to the host memory, in MB
+ --Outbound Read(MB) - CPU reads from I/O devices below IIO stack, in MB
+ --Outbound Write(MB) - CPU writes to I/O devices below IIO stack, in MB
+
+Sample output:
+
+Show all IIO stacks on 2-S platform:
+ $ perf stat --iiostat=show
+ S0-uncore_iio_0<0000:00>
+ S1-uncore_iio_0<0000:80>
+ S0-uncore_iio_1<0000:17>
+ S1-uncore_iio_1<0000:85>
+ S0-uncore_iio_2<0000:3a>
+ S1-uncore_iio_2<0000:ae>
+ S0-uncore_iio_3<0000:5d>
+ S1-uncore_iio_3<0000:d7>
+
+Print metrics for requested IIO stacks, multiple comma-separated list supported.
+ $ perf stat --iiostat=0000:17 -- dd if=/dev/zero of=/dev/nvme0n1 bs=1M oflag=direct
+ 357708+0 records in
+ 357707+0 records out
+ 375083606016 bytes (375 GB, 349 GiB) copied, 213.997 s, 1.8 GB/s
+
+ Performance counter stats for 'system wide':
+
+ port Inbound Read(MB) Inbound Write(MB) Outbound Read(MB) Outbound Write(MB)
+ 0000:17 358559 44 0 22

-n::
--null::
diff --git a/tools/perf/arch/x86/util/Build b/tools/perf/arch/x86/util/Build
index 347c39b960eb..6fa275d3d897 100644
--- a/tools/perf/arch/x86/util/Build
+++ b/tools/perf/arch/x86/util/Build
@@ -6,6 +6,7 @@ perf-y += perf_regs.o
perf-y += topdown.o
perf-y += machine.o
perf-y += event.o
+perf-y += iiostat.o

perf-$(CONFIG_DWARF) += dwarf-regs.o
perf-$(CONFIG_BPF_PROLOGUE) += dwarf-regs.o
diff --git a/tools/perf/arch/x86/util/iiostat.c b/tools/perf/arch/x86/util/iiostat.c
index 70f93a96723f..44342a111746 100644
--- a/tools/perf/arch/x86/util/iiostat.c
+++ b/tools/perf/arch/x86/util/iiostat.c
@@ -27,6 +27,44 @@
#include "util/counts.h"
#include "path.h"

+#ifndef MAX_PATH
+#define MAX_PATH 1024
+#endif
+
+#define UNCORE_IIO_PMU_PATH "devices/uncore_iio_%d"
+#define SYSFS_UNCORE_PMU_PATH "%s/"UNCORE_IIO_PMU_PATH
+#define PLATFORM_MAPPING_PATH UNCORE_IIO_PMU_PATH"/die%d"
+
+enum iiostat_mode_t {
+ IIOSTAT_NONE = -1,
+ IIOSTAT_RUN = 0,
+ IIOSTAT_SHOW = 1
+};
+
+static enum iiostat_mode_t iiostat_mode = IIOSTAT_NONE;
+
+/*
+ * Each metric requiries only one IIO event which increments at every 4B transfer
+ * in corresponding direction. The formulas to compute metrics are generic:
+ * #EventCount * 4B / (1024 * 1024)
+ */
+static const char * const iiostat_metrics[] = {
+ "Inbound Read(MB)",
+ "Inbound Write(MB)",
+ "Outbound Read(MB)",
+ "Outbound Write(MB)",
+};
+
+static inline int iiostat_metrics_count(void)
+{
+ return sizeof(iiostat_metrics) / sizeof(char *);
+}
+
+static const char *iiostat_metric_by_idx(int idx)
+{
+ return *(iiostat_metrics + idx % iiostat_metrics_count());
+}
+
struct iio_root_port {
u32 domain;
u8 bus;
@@ -123,3 +161,300 @@ static int iio_root_ports_list_insert(struct iio_root_ports_list *list,
}
return 0;
}
+
+static int uncore_pmu_iio_platform_mapping(u8 pmu_idx, struct iio_root_ports_list * const list)
+{
+ char *buf;
+ char path[MAX_PATH];
+ u32 domain;
+ u8 bus;
+ struct iio_root_port *rp;
+ size_t size;
+ int ret;
+
+ for (int die = 0; die < cpu__max_node(); die++) {
+ scnprintf(path, MAX_PATH, PLATFORM_MAPPING_PATH, pmu_idx, die);
+ if (sysfs__read_str(path, &buf, &size) < 0) {
+ if (pmu_idx)
+ goto out;
+ pr_err("Mode iiostat is not supported\n");
+ return -1;
+ }
+ ret = sscanf(buf, "%04x:%02hhx", &domain, &bus);
+ free(buf);
+ if (ret != 2) {
+ pr_err("Invalid mapping data: iio_%d; die%d\n", pmu_idx, die);
+ return -1;
+ }
+ rp = iio_root_port_new(domain, bus, die, pmu_idx);
+ if (!rp || iio_root_ports_list_insert(list, rp)) {
+ free(rp);
+ return -ENOMEM;
+ }
+ }
+out:
+ return 0;
+}
+
+static u8 iio_pmu_count(void)
+{
+ u8 pmu_idx = 0;
+ char path[MAX_PATH];
+ const char *sysfs = sysfs__mountpoint();
+
+ if (sysfs) {
+ for (;; pmu_idx++) {
+ snprintf(path, sizeof(path), SYSFS_UNCORE_PMU_PATH,
+ sysfs, pmu_idx);
+ if (access(path, F_OK) != 0)
+ break;
+ }
+ }
+ return pmu_idx;
+}
+
+static int iio_root_ports_scan(struct iio_root_ports_list **list)
+{
+ int ret = -ENOMEM;
+ struct iio_root_ports_list *tmp_list;
+ u8 pmu_count = iio_pmu_count();
+
+ if (!pmu_count) {
+ pr_err("Unsupported uncore pmu configuration\n");
+ return -1;
+ }
+
+ tmp_list = iio_root_ports_list_new();
+ if (!tmp_list)
+ goto err;
+
+ for (u8 pmu_idx = 0; pmu_idx < pmu_count; pmu_idx++) {
+ ret = uncore_pmu_iio_platform_mapping(pmu_idx, tmp_list);
+ if (ret)
+ break;
+ }
+err:
+ if (!ret)
+ *list = tmp_list;
+ else
+ iio_root_ports_list_free(tmp_list);
+
+ return ret;
+}
+
+static int iio_root_port_parse_str(u32 *domain, u8 *bus, char *str)
+{
+ int ret;
+ regex_t regex;
+ /*
+ * Expected format domain:bus:
+ * Valid domain range [0:ffff]
+ * Valid bus range [0:ff]
+ * Example: 0000:af, 0:3d, 01:7
+ */
+ regcomp(&regex, "^([a-f0-9A-F]{1,}):([a-f0-9A-F]{1,2})$", REG_EXTENDED);
+ ret = regexec(&regex, str, 0, NULL, 0);
+ if (ret || sscanf(str, "%08x:%02hhx", domain, bus) != 2)
+ pr_warning("Unrecognized root port format: %s\n"
+ "Please use the following format:\n"
+ "\t [domain]:[bus]\n"
+ "\t for example: 0000:3d\n", str);
+
+ regfree(&regex);
+ return ret;
+}
+
+static int iio_root_ports_list_filter(struct iio_root_ports_list **list,
+ const char *filter)
+{
+ char *tok, *tmp, *filter_copy = NULL;
+ struct iio_root_port *rp;
+ u32 domain;
+ u8 bus;
+ int ret = -ENOMEM;
+ struct iio_root_ports_list *tmp_list = iio_root_ports_list_new();
+
+ if (!tmp_list)
+ goto err;
+
+ filter_copy = strdup(filter);
+ if (!filter_copy)
+ goto err;
+
+ for (tok = strtok_r(filter_copy, ",", &tmp); tok; tok = strtok_r(NULL, ",", &tmp)) {
+ if (!iio_root_port_parse_str(&domain, &bus, tok)) {
+ rp = iio_root_port_find_by_notation(*list, domain, bus);
+ if (rp) {
+ (*list)->rps[rp->idx] = NULL;
+ ret = iio_root_ports_list_insert(tmp_list, rp);
+ if (ret) {
+ free(rp);
+ goto err;
+ }
+ } else if (!iio_root_port_find_by_notation(tmp_list, domain, bus))
+ pr_warning("Root port %04x:%02x were not found\n", domain, bus);
+ }
+ }
+
+ if (tmp_list->nr_entries == 0) {
+ pr_err("Requested root ports were not found\n");
+ ret = -EINVAL;
+ }
+err:
+ iio_root_ports_list_free(*list);
+ if (ret)
+ iio_root_ports_list_free(tmp_list);
+ else
+ *list = tmp_list;
+
+ free(filter_copy);
+ return ret;
+}
+
+static int iiostat_event_group(struct evlist *evl, struct iio_root_ports_list *list)
+{
+ int ret;
+ struct iio_root_port **rp;
+ const char *iiostat_cmd_template =
+ "{uncore_iio_%x/event=0x83,umask=0x04,ch_mask=0xF,fc_mask=0x07/,\
+ uncore_iio_%x/event=0x83,umask=0x01,ch_mask=0xF,fc_mask=0x07/,\
+ uncore_iio_%x/event=0xc0,umask=0x04,ch_mask=0xF,fc_mask=0x07/,\
+ uncore_iio_%x/event=0xc0,umask=0x01,ch_mask=0xF,fc_mask=0x07/}";
+ const int len_template = strlen(iiostat_cmd_template) + 1;
+ struct evsel *evsel = NULL;
+ int metrics_count = iiostat_metrics_count();
+ char *iiostat_cmd = calloc(len_template, 1);
+
+ if (!iiostat_cmd)
+ return -ENOMEM;
+
+ for (rp = list->rps; *rp; rp++) {
+ sprintf(iiostat_cmd, iiostat_cmd_template,
+ (*rp)->pmu_idx, (*rp)->pmu_idx, (*rp)->pmu_idx, (*rp)->pmu_idx);
+ ret = parse_events(evl, iiostat_cmd, NULL);
+ if (ret)
+ goto err;
+ }
+
+ evlist__for_each_entry(evl, evsel) {
+ evsel->perf_device = list->rps[evsel->idx / metrics_count];
+ }
+ list->nr_entries = 0;
+err:
+ iio_root_ports_list_free(list);
+ free(iiostat_cmd);
+ return ret;
+}
+
+int iiostat_parse(const struct option *opt, const char *str,
+ int unset __maybe_unused)
+{
+ int ret;
+ struct iio_root_ports_list *list;
+ struct evlist *evl = *(struct evlist **)opt->value;
+ struct perf_stat_config *config = (struct perf_stat_config *)opt->data;
+
+ if (evl->core.nr_entries > 0) {
+ pr_err("Unsupported event configuration\n");
+ return -1;
+ }
+ config->metric_only = true;
+ config->aggr_mode = AGGR_IIO_STACK;
+ config->iiostat_run = true;
+ ret = iio_root_ports_scan(&list);
+ if (ret)
+ return ret;
+
+ if (!str) {
+ iiostat_mode = IIOSTAT_RUN;
+ } else if (!strcmp(str, "show")) {
+ iiostat_mode = IIOSTAT_SHOW;
+ } else {
+ iiostat_mode = IIOSTAT_RUN;
+ ret = iio_root_ports_list_filter(&list, str);
+ if (ret)
+ return ret;
+ }
+ return iiostat_event_group(evl, list);
+}
+
+void iiostat_prefix(struct perf_stat_config *config,
+ struct evlist *evlist,
+ char *prefix, struct timespec *ts)
+{
+ struct iio_root_port *rp = evlist->selected->perf_device;
+
+ if (rp) {
+ if (ts)
+ sprintf(prefix, "%6lu.%09lu%s%04x:%02x%s",
+ ts->tv_sec, ts->tv_nsec,
+ config->csv_sep, rp->domain, rp->bus,
+ config->csv_sep);
+ else
+ sprintf(prefix, "%04x:%02x%s", rp->domain, rp->bus,
+ config->csv_sep);
+ }
+}
+
+void iiostat_print_metric(struct perf_stat_config *config, struct evsel *evsel,
+ struct perf_stat_output_ctx *out)
+{
+ double iiostat_value = 0;
+ u64 prev_count_val = 0;
+ const char *iiostat_metric = iiostat_metric_by_idx(evsel->idx);
+ u8 die = ((struct iio_root_port *)evsel->perf_device)->die;
+ struct perf_counts_values *count = perf_counts(evsel->counts, die, 0);
+
+ if (evsel->prev_raw_counts && !out->force_header) {
+ struct perf_counts_values *prev_count = perf_counts(evsel->prev_raw_counts, die, 0);
+
+ prev_count_val = prev_count->val;
+ prev_count->val = count->val;
+ }
+ iiostat_value = (count->val - prev_count_val) / ((double) count->run / count->ena);
+ out->print_metric(config, out->ctx, NULL, "%8.0f", iiostat_metric,
+ iiostat_value / (256 * 1024));
+}
+
+int iiostat_show_root_ports(struct evlist *evlist, struct perf_stat_config *config)
+{
+ struct evsel *evsel;
+ struct iio_root_port *rp = NULL;
+ bool is_show_mode = (iiostat_mode == IIOSTAT_SHOW);
+
+ if (config->aggr_mode != AGGR_IIO_STACK) {
+ pr_err("Unsupported event configuration\n");
+ return -1;
+ }
+
+ if (is_show_mode || verbose) {
+ evlist__for_each_entry(evlist, evsel) {
+ if (!evsel->perf_device) {
+ pr_err("Unsupported event configuration\n");
+ return -1;
+ }
+ if (rp != evsel->perf_device) {
+ rp = evsel->perf_device;
+ iio_root_port_show(config->output, rp);
+ }
+ }
+ }
+ /* Stop iiostat for show mode*/
+ config->iiostat_run = !is_show_mode;
+ if (is_show_mode)
+ iiostat_delete_root_ports(evlist);
+ return 0;
+}
+
+void iiostat_delete_root_ports(struct evlist *evlist)
+{
+ struct evsel *evsel;
+ struct iio_root_port *rp = NULL;
+
+ evlist__for_each_entry(evlist, evsel) {
+ if (rp != evsel->perf_device) {
+ rp = evsel->perf_device;
+ free(evsel->perf_device);
+ }
+ }
+}
--
2.19.1