[PATCH v4 4/5] perf stat: Enable iostat mode for x86 platforms

From: Alexander Antonov
Date: Wed Feb 03 2021 - 09:03:20 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
PCIe root port:
- Inbound Read: I/O devices below root port read from the host memory
- Inbound Write: I/O devices below root port write to the host memory
- Outbound Read: CPU reads from I/O devices below root port
- Outbound Write: CPU writes to I/O devices below root port

Each metric requiries only one uncore 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-iostat.txt | 88 ++++++
tools/perf/Makefile.perf | 5 +-
tools/perf/arch/x86/util/Build | 1 +
tools/perf/arch/x86/util/iostat.c | 345 +++++++++++++++++++++++
tools/perf/command-list.txt | 1 +
tools/perf/perf-iostat.sh | 12 +
6 files changed, 451 insertions(+), 1 deletion(-)
create mode 100644 tools/perf/Documentation/perf-iostat.txt
create mode 100644 tools/perf/perf-iostat.sh

diff --git a/tools/perf/Documentation/perf-iostat.txt b/tools/perf/Documentation/perf-iostat.txt
new file mode 100644
index 000000000000..165176944031
--- /dev/null
+++ b/tools/perf/Documentation/perf-iostat.txt
@@ -0,0 +1,88 @@
+perf-iostat(1)
+===============
+
+NAME
+----
+perf-iostat - Show I/O performance metrics
+
+SYNOPSIS
+--------
+[verse]
+'perf iostat' list
+'perf iostat' <ports> -- <command> [<options>]
+
+DESCRIPTION
+-----------
+Mode is intended to provide four I/O performance metrics per each PCIe root port:
+
+- Inbound Read - I/O devices below root port read from the host memory, in MB
+
+- Inbound Write - I/O devices below root port write to the host memory, in MB
+
+- Outbound Read - CPU reads from I/O devices below root port, in MB
+
+- Outbound Write - CPU writes to I/O devices below root port, in MB
+
+OPTIONS
+-------
+<command>...::
+ Any command you can specify in a shell.
+
+list::
+ List all PCIe root ports.
+
+<ports>::
+ Select the root ports for monitoring. Comma-separated list is supported.
+
+EXAMPLES
+--------
+
+1. List all PCIe root ports (example for 2-S platform):
+
+ $ perf iostat list
+ 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>
+
+2. Collect metrics for all PCIe root ports:
+
+ $ perf iostat -- 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, 215.974 s, 1.7 GB/s
+
+ Performance counter stats for 'system wide':
+
+ port Inbound Read(MB) Inbound Write(MB) Outbound Read(MB) Outbound Write(MB)
+ 0000:00 1 0 2 3
+ 0000:80 0 0 0 0
+ 0000:17 352552 43 0 21
+ 0000:85 0 0 0 0
+ 0000:3a 3 0 0 0
+ 0000:ae 0 0 0 0
+ 0000:5d 0 0 0 0
+ 0000:d7 0 0 0 0
+
+3. Collect metrics for comma-separated list of PCIe root ports:
+
+ $ perf iostat 0000:17,0:3a -- 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, 197.08 s, 1.9 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
+ 0000:3a 3 2 0 0
+
+ 197.081983474 seconds time elapsed
+
+SEE ALSO
+--------
+linkperf:perf-stat[1]
\ No newline at end of file
diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
index 902c792f326a..b4ab48cc01e3 100644
--- a/tools/perf/Makefile.perf
+++ b/tools/perf/Makefile.perf
@@ -267,6 +267,7 @@ SCRIPT_SH =

SCRIPT_SH += perf-archive.sh
SCRIPT_SH += perf-with-kcore.sh
+SCRIPT_SH += perf-iostat.sh

grep-libs = $(filter -l%,$(1))
strip-libs = $(filter-out -l%,$(1))
@@ -890,6 +891,8 @@ endif
$(INSTALL) $(OUTPUT)perf-archive -t '$(DESTDIR_SQ)$(perfexec_instdir_SQ)'
$(call QUIET_INSTALL, perf-with-kcore) \
$(INSTALL) $(OUTPUT)perf-with-kcore -t '$(DESTDIR_SQ)$(perfexec_instdir_SQ)'
+ $(call QUIET_INSTALL, perf-iostat) \
+ $(INSTALL) $(OUTPUT)perf-iostat -t '$(DESTDIR_SQ)$(perfexec_instdir_SQ)'
ifndef NO_LIBAUDIT
$(call QUIET_INSTALL, strace/groups) \
$(INSTALL) -d -m 755 '$(DESTDIR_SQ)$(STRACE_GROUPS_INSTDIR_SQ)'; \
@@ -954,7 +957,7 @@ python-clean:
$(python-clean)

clean:: $(LIBTRACEEVENT)-clean $(LIBAPI)-clean $(LIBBPF)-clean $(LIBSUBCMD)-clean $(LIBPERF)-clean config-clean fixdep-clean python-clean
- $(call QUIET_CLEAN, core-objs) $(RM) $(LIBPERF_A) $(OUTPUT)perf-archive $(OUTPUT)perf-with-kcore $(LANG_BINDINGS)
+ $(call QUIET_CLEAN, core-objs) $(RM) $(LIBPERF_A) $(OUTPUT)perf-archive $(OUTPUT)perf-with-kcore $(OUTPUT)perf-iostat $(LANG_BINDINGS)
$(Q)find $(if $(OUTPUT),$(OUTPUT),.) -name '*.o' -delete -o -name '\.*.cmd' -delete -o -name '\.*.d' -delete
$(Q)$(RM) $(OUTPUT).config-detected
$(call QUIET_CLEAN, core-progs) $(RM) $(ALL_PROGRAMS) perf perf-read-vdso32 perf-read-vdsox32 $(OUTPUT)pmu-events/jevents $(OUTPUT)$(LIBJVMTI).so
diff --git a/tools/perf/arch/x86/util/Build b/tools/perf/arch/x86/util/Build
index 47f9c56e744f..5b650bebee78 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 += group.o
perf-y += machine.o
perf-y += event.o
+perf-y += iostat.o

perf-$(CONFIG_DWARF) += dwarf-regs.o
perf-$(CONFIG_BPF_PROLOGUE) += dwarf-regs.o
diff --git a/tools/perf/arch/x86/util/iostat.c b/tools/perf/arch/x86/util/iostat.c
index 961e540106e6..468a9696a12d 100644
--- a/tools/perf/arch/x86/util/iostat.c
+++ b/tools/perf/arch/x86/util/iostat.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 iostat_mode_t {
+ IOSTAT_NONE = -1,
+ IOSTAT_RUN = 0,
+ IOSTAT_LIST = 1
+};
+
+static enum iostat_mode_t iostat_mode = IOSTAT_NONE;
+
+/*
+ * Each metric requiries 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 iostat_metrics[] = {
+ "Inbound Read(MB)",
+ "Inbound Write(MB)",
+ "Outbound Read(MB)",
+ "Outbound Write(MB)",
+};
+
+static inline int iostat_metrics_count(void)
+{
+ return sizeof(iostat_metrics) / sizeof(char *);
+}
+
+static const char *iostat_metric_by_idx(int idx)
+{
+ return *(iostat_metrics + idx % iostat_metrics_count());
+}
+
struct iio_root_port {
u32 domain;
u8 bus;
@@ -122,3 +160,310 @@ static int iio_root_ports_list_insert(struct iio_root_ports_list *list,
}
return 0;
}
+
+static int iio_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 iostat 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 = iio_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 iostat_event_group(struct evlist *evl,
+ struct iio_root_ports_list *list)
+{
+ int ret;
+ int idx;
+ const char *iostat_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(iostat_cmd_template) + 1;
+ struct evsel *evsel = NULL;
+ int metrics_count = iostat_metrics_count();
+ char *iostat_cmd = calloc(len_template, 1);
+
+ if (!iostat_cmd)
+ return -ENOMEM;
+
+ for (idx = 0; idx < list->nr_entries; idx++) {
+ sprintf(iostat_cmd, iostat_cmd_template,
+ list->rps[idx]->pmu_idx, list->rps[idx]->pmu_idx,
+ list->rps[idx]->pmu_idx, list->rps[idx]->pmu_idx);
+ ret = parse_events(evl, iostat_cmd, NULL);
+ if (ret)
+ goto err;
+ }
+
+ evlist__for_each_entry(evl, evsel) {
+ evsel->priv = list->rps[evsel->idx / metrics_count];
+ }
+ list->nr_entries = 0;
+err:
+ iio_root_ports_list_free(list);
+ free(iostat_cmd);
+ return ret;
+}
+
+int iostat_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_PCIE_PORT;
+ config->iostat_run = true;
+ ret = iio_root_ports_scan(&list);
+ if (ret)
+ return ret;
+
+ if (!str) {
+ iostat_mode = IOSTAT_RUN;
+ } else if (!strcmp(str, "list")) {
+ iostat_mode = IOSTAT_LIST;
+ } else {
+ iostat_mode = IOSTAT_RUN;
+ ret = iio_root_ports_list_filter(&list, str);
+ if (ret)
+ return ret;
+ }
+ return iostat_event_group(evl, list);
+}
+
+void iostat_prefix(struct perf_stat_config *config,
+ struct evlist *evlist,
+ char *prefix, struct timespec *ts)
+{
+ struct iio_root_port *rp = evlist->selected->priv;
+
+ 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 iostat_print_metric(struct perf_stat_config *config, struct evsel *evsel,
+ struct perf_stat_output_ctx *out)
+{
+ double iostat_value = 0;
+ u64 prev_count_val = 0;
+ const char *iostat_metric = iostat_metric_by_idx(evsel->idx);
+ u8 die = ((struct iio_root_port *)evsel->priv)->die;
+ struct perf_counts_values *count = perf_counts(evsel->counts, die, 0);
+
+ if (count->run && count->ena) {
+ 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;
+ }
+ iostat_value = (count->val - prev_count_val) /
+ ((double) count->run / count->ena);
+ }
+ out->print_metric(config, out->ctx, NULL, "%8.0f", iostat_metric,
+ iostat_value / (256 * 1024));
+}
+
+int iostat_list(struct evlist *evlist, struct perf_stat_config *config)
+{
+ struct evsel *evsel;
+ struct iio_root_port *rp = NULL;
+ bool is_list_mode = (iostat_mode == IOSTAT_LIST);
+
+ if (config->aggr_mode != AGGR_PCIE_PORT) {
+ pr_err("Unsupported event configuration\n");
+ return -1;
+ }
+
+ if (is_list_mode || verbose) {
+ evlist__for_each_entry(evlist, evsel) {
+ if (!evsel->priv) {
+ pr_err("Unsupported event configuration\n");
+ return -1;
+ }
+ if (rp != evsel->priv) {
+ rp = evsel->priv;
+ iio_root_port_show(config->output, rp);
+ }
+ }
+ }
+ /* Stop iostat in list-mode*/
+ config->iostat_run = !is_list_mode;
+ if (is_list_mode)
+ iostat_release(evlist);
+ return 0;
+}
+
+void iostat_release(struct evlist *evlist)
+{
+ struct evsel *evsel;
+ struct iio_root_port *rp = NULL;
+
+ evlist__for_each_entry(evlist, evsel) {
+ if (rp != evsel->priv) {
+ rp = evsel->priv;
+ free(evsel->priv);
+ }
+ }
+}
diff --git a/tools/perf/command-list.txt b/tools/perf/command-list.txt
index bc6c585f74fc..620db1e8e6a7 100644
--- a/tools/perf/command-list.txt
+++ b/tools/perf/command-list.txt
@@ -14,6 +14,7 @@ perf-config mainporcelain common
perf-evlist mainporcelain common
perf-ftrace mainporcelain common
perf-inject mainporcelain common
+perf-iostat mainporcelain common
perf-kallsyms mainporcelain common
perf-kmem mainporcelain common
perf-kvm mainporcelain common
diff --git a/tools/perf/perf-iostat.sh b/tools/perf/perf-iostat.sh
new file mode 100644
index 000000000000..e562f252d56f
--- /dev/null
+++ b/tools/perf/perf-iostat.sh
@@ -0,0 +1,12 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# perf iostat
+# Alexander Antonov <alexander.antonov@xxxxxxxxxxxxxxx>
+
+if [[ "$1" == "list" ]] || [[ "$1" =~ ([a-f0-9A-F]{1,}):([a-f0-9A-F]{1,2})(,)? ]]; then
+ DELIMITER="="
+else
+ DELIMITER=" "
+fi
+
+perf stat --iostat$DELIMITER$*
--
2.19.1