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perf/core improvements and fixes

GIT PULL New Arnaldo Carvalho de Melo 2 participants 13 messages Jun 6, 2016 – Jun 8, 2016 perf events

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Arnaldo Carvalho de Melo

author maintainer
#0 lore raw

Hi Ingo,

Please consider pulling,

- Arnaldo

The following changes since commit 030ba6cd105c68ce919c5e239853b567490cd059:

perf/x86/intel: Use new topology_max_smt_threads() in HT leak workaround (2016-06-03 09:41:25 +0200)

are available in the git repository at:

git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git tags/perf-core-for-mingo-20160606

for you to fetch changes up to 7db91f251056f90fec4121f028680ab3153a0f3c:

perf config: Handle the error when config set is NULL at collect_config() (2016-06-06 17:43:19 -0300)

----------------------------------------------------------------
perf/core improvements and fixes:

User visible:

- Tooling support for TopDown counters, recently added to the kernel (Andi Kleen)

- Show call graphs in 'perf script' when 1st event doesn't have it but some other has (He Kuang)

- Fix terminal cleanup when handling invalid .perfconfig files in 'perf top' (Taeung Song)

Build fixes:

- Respect CROSS_COMPILE for the linker in libapi (Lucas Stach)

Infrastructure:

- Fix perf_evlist__alloc_mmap() failure path (Wang Nan)

- Provide way to extract integer value from format_field (Arnaldo Carvalho de Melo)

----------------------------------------------------------------
Andi Kleen (5):
perf test: Ignore .scale and other special files
perf stat: Basic support for TopDown in perf stat perf stat: Add computation of TopDown formulas
perf stat: Print topology/time headers with --metric-only perf stat: Add missing aggregation headers for --metric-only CSV

Arnaldo Carvalho de Melo (1):
perf evsel: Provide way to extract integer value from format_field

He Kuang (1):
perf script: Show call graphs when 1st event doesn't have it but some other has

Lucas Stach (1):
tools lib api: Respect CROSS_COMPILE for the linker

Taeung Song (2):
perf config: Fix abnormal termination at perf_parse_file() perf config: Handle the error when config set is NULL at collect_config()

Wang Nan (1):
perf evlist: Fix alloc_mmap() failure path

 tools/lib/api/Makefile                 |   1 +
 tools/perf/Documentation/perf-stat.txt |  32 +++++++
 tools/perf/arch/x86/util/Build         |   1 +
 tools/perf/arch/x86/util/group.c       |  27 ++++++
 tools/perf/builtin-script.c            |  23 +++--
 tools/perf/builtin-stat.c              | 165 ++++++++++++++++++++++++++++++---
 tools/perf/tests/parse-events.c        |   4 +-
 tools/perf/util/config.c               |  22 +++--
 tools/perf/util/evlist.c               |   5 +-
 tools/perf/util/evsel.c                |  25 +++--
 tools/perf/util/evsel.h                |   2 +
 tools/perf/util/group.h                |   7 ++
 tools/perf/util/parse-events.l         |   1 +
 tools/perf/util/stat-shadow.c          | 162 ++++++++++++++++++++++++++++++++
 tools/perf/util/stat.c                 |   5 +
 tools/perf/util/stat.h                 |   5 +
 16 files changed, 441 insertions(+), 46 deletions(-)
 create mode 100644 tools/perf/arch/x86/util/group.c
 create mode 100644 tools/perf/util/group.h
author maintainer
#1 lore raw

PATCH 1/11 perf evsel: Provide way to extract integer value from format_field

From: Arnaldo Carvalho de Melo <[email protected]>

Out of perf_evsel__intval(), that requires passing the variable name, that will then be searched in the list of tracepoint variables for the given evsel.

In cases such as syscall file descriptor ("fd") tracking, this is wasteful, we need just to use perf_evsel__field() and cache the format_field.

---
 tools/perf/util/evsel.c | 25 +++++++++++++++----------
 tools/perf/util/evsel.h |  2 ++
 2 files changed, 17 insertions(+), 10 deletions(-)
tools/perf/util/evsel.c +15 -10
index 8d30cbda51b6..f4f01b2e9dcc 100644
@@ -2251,17 +2251,11 @@ void *perf_evsel__rawptr(struct perf_evsel *evsel, struct perf_sample *sample,
 	return sample->raw_data + offset;
 }
 
-u64 perf_evsel__intval(struct perf_evsel *evsel, struct perf_sample *sample,
-		       const char *name)
+u64 format_field__intval(struct format_field *field, struct perf_sample *sample,
+			 bool needs_swap)
 {
-	struct format_field *field = perf_evsel__field(evsel, name);
-	void *ptr;
 	u64 value;
-
-	if (!field)
-		return 0;
-
-	ptr = sample->raw_data + field->offset;
+	void *ptr = sample->raw_data + field->offset;
 
 	switch (field->size) {
 	case 1:
@@ -2279,7 +2273,7 @@ u64 perf_evsel__intval(struct perf_evsel *evsel, struct perf_sample *sample,
 		return 0;
 	}
 
-	if (!evsel->needs_swap)
+	if (!needs_swap)
 		return value;
 
 	switch (field->size) {
@@ -2296,6 +2290,17 @@ u64 perf_evsel__intval(struct perf_evsel *evsel, struct perf_sample *sample,
 	return 0;
 }
 
+u64 perf_evsel__intval(struct perf_evsel *evsel, struct perf_sample *sample,
+		       const char *name)
+{
+	struct format_field *field = perf_evsel__field(evsel, name);
+
+	if (!field)
+		return 0;
+
+	return field ? format_field__intval(field, sample, evsel->needs_swap) : 0;
+}
+
 bool perf_evsel__fallback(struct perf_evsel *evsel, int err,
 			  char *msg, size_t msgsize)
 {
tools/perf/util/evsel.h +2 -0
index 028412b32d5a..828ddd1c8947 100644
@@ -261,6 +261,8 @@ static inline char *perf_evsel__strval(struct perf_evsel *evsel,
 
 struct format_field;
 
+u64 format_field__intval(struct format_field *field, struct perf_sample *sample, bool needs_swap);
+
 struct format_field *perf_evsel__field(struct perf_evsel *evsel, const char *name);
 
 #define perf_evsel__match(evsel, t, c)		\
Signature · 1 line
2.5.5
author maintainer
#2 lore raw

PATCH 2/11 perf evlist: Fix alloc_mmap() failure path

In reply to Arnaldo Carvalho de Melo

From: Wang Nan <[email protected]>

If zalloc fail, setting evlist->mmap[i].fd is unsafe and perf_evlist__alloc_mmap() should bail out right after that.

---
 tools/perf/util/evlist.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)
tools/perf/util/evlist.c +4 -1
index e0f30946ed1a..1b918aa075d6 100644
@@ -946,9 +946,12 @@ static int perf_evlist__alloc_mmap(struct perf_evlist *evlist)
 	if (cpu_map__empty(evlist->cpus))
 		evlist->nr_mmaps = thread_map__nr(evlist->threads);
 	evlist->mmap = zalloc(evlist->nr_mmaps * sizeof(struct perf_mmap));
+	if (!evlist->mmap)
+		return -ENOMEM;
+
 	for (i = 0; i < evlist->nr_mmaps; i++)
 		evlist->mmap[i].fd = -1;
-	return evlist->mmap != NULL ? 0 : -ENOMEM;
+	return 0;
 }
 
 struct mmap_params {
Signature · 1 line
2.5.5
author maintainer
#3 lore raw

PATCH 3/11 tools lib api: Respect CROSS_COMPILE for the linker

In reply to Arnaldo Carvalho de Melo

From: Lucas Stach <[email protected]>

This fixes cross compilation of libapi.

---
 tools/lib/api/Makefile | 1 +
 1 file changed, 1 insertion(+)
tools/lib/api/Makefile +1 -0
index 316f308a63ea..67ff93ec1515 100644
@@ -10,6 +10,7 @@ endif
 
 CC = $(CROSS_COMPILE)gcc
 AR = $(CROSS_COMPILE)ar
+LD = $(CROSS_COMPILE)ld
 
 MAKEFLAGS += --no-print-directory
 
Signature · 1 line
2.5.5
author maintainer
#4 lore raw

PATCH 4/11 perf script: Show call graphs when 1st event doesn't have it but some other has

In reply to Arnaldo Carvalho de Melo

From: He Kuang <[email protected]>

There's a display inconsistency when there are multiple tracepoint events, some of which have the 'call-graph' config option set but the first one hasn't, i.e. the whole logic for call graph processing is enabled only if the first tracepoint event has call-graph set.

For instance, if we record signal_deliver with call-graph and signal_generate without:

  $ perf record -g -a -e signal:signal_deliver -e signal:signal_generate/call-graph=no/

[ perf record: Captured and wrote 0.017 MB perf.data (2 samples) ]

  $ perf script

kworker/u2:1 13 [000] 6563.875949: signal:signal_generate: sig=2 errno=0 code=128 comm=perf pid=1313 grp=1 res=0 ff61cc __send_signal+0x3ec ([kernel.kallsyms])
perf 1313 [000] 6563.877584: signal:signal_deliver: sig=2 errno=0 code=128 sa_handler=43115e sa_flags=14000000

              7ffff314 get_signal+0x80007f0023a4 ([kernel.kallsyms])
              7fffe358 do_signal+0x80007f002028 ([kernel.kallsyms])
              7fffa5e8 exit_to_usermode_loop+0x80007f002053 ([kernel.kallsyms])
              ...

Then we exchange the order of these two events in commandline, and keep signal_generate without call-graph.

  $ perf record -g -a -e signal:signal_generate/call-graph=no/ -e signal:signal_deliver

[ perf record: Captured and wrote 0.017 MB perf.data (2 samples) ]

  $ perf script
    kworker/u2:2  1314 [000]  6933.353060: signal:signal_generate: sig=2 errno=0 code=128 comm=perf pid=1321 grp=1 res=0
            perf  1321 [000]  6933.353872:  signal:signal_deliver: sig=2 errno=0 code=128 sa_handler=43115e sa_flags=14000000

This time, the callchain of the event signal_deliver disappeared. The problem is caused by that perf only checks for the first evsel in evlist and decides if callchain should be printed.

This patch traverses all evsels in evlist to see if any of them have callchains, and shows the right result:

  $ perf script

kworker/u2:2 1314 [000] 6933.353060: signal:signal_generate: sig=2 errno=0 code=128 comm=perf pid=1321 grp=1 res=0 ff61cc __send_signal+0x3ec ([kernel.kallsyms]) perf 1321 [000] 6933.353872: signal:signal_deliver: sig=2 errno=0 code=128 sa_handler=43115e sa_flags=14000000

              7ffff314 get_signal+0x80007f0023a4 ([kernel.kallsyms])
              7fffe358 do_signal+0x80007f002028 ([kernel.kallsyms])
              7fffa5e8 exit_to_usermode_loop+0x80007f002053 ([kernel.kallsyms])
              ...
---
 tools/perf/builtin-script.c | 23 +++++++++++++----------
 1 file changed, 13 insertions(+), 10 deletions(-)
tools/perf/builtin-script.c +13 -10
index e3ce2f34d3ad..46011235af5d 100644
@@ -339,7 +339,7 @@ static void set_print_ip_opts(struct perf_event_attr *attr)
  */
 static int perf_session__check_output_opt(struct perf_session *session)
 {
-	int j;
+	unsigned int j;
 	struct perf_evsel *evsel;
 
 	for (j = 0; j < PERF_TYPE_MAX; ++j) {
@@ -388,17 +388,20 @@ static int perf_session__check_output_opt(struct perf_session *session)
 		struct perf_event_attr *attr;
 
 		j = PERF_TYPE_TRACEPOINT;
-		evsel = perf_session__find_first_evtype(session, j);
-		if (evsel == NULL)
-			goto out;
 
-		attr = &evsel->attr;
+		evlist__for_each(session->evlist, evsel) {
+			if (evsel->attr.type != j)
+				continue;
+
+			attr = &evsel->attr;
 
-		if (attr->sample_type & PERF_SAMPLE_CALLCHAIN) {
-			output[j].fields |= PERF_OUTPUT_IP;
-			output[j].fields |= PERF_OUTPUT_SYM;
-			output[j].fields |= PERF_OUTPUT_DSO;
-			set_print_ip_opts(attr);
+			if (attr->sample_type & PERF_SAMPLE_CALLCHAIN) {
+				output[j].fields |= PERF_OUTPUT_IP;
+				output[j].fields |= PERF_OUTPUT_SYM;
+				output[j].fields |= PERF_OUTPUT_DSO;
+				set_print_ip_opts(attr);
+				goto out;
+			}
 		}
 	}
 
Signature · 1 line
2.5.5
author maintainer
#5 lore raw

PATCH 5/11 perf test: Ignore .scale and other special files

In reply to Arnaldo Carvalho de Melo

From: Andi Kleen <[email protected]>

'perf test' tries to parse all entries in /sys/devices/cpu/events/. Ignore the special entries like '.scale', which cannot be directly parsed as an event. This patch assumes all files containing a '.' are special and can be ignored.

---
 tools/perf/tests/parse-events.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
tools/perf/tests/parse-events.c +2 -2
index 7865f68dc0d8..b2a2c74136a5 100644
@@ -1783,8 +1783,8 @@ static int test_pmu_events(void)
 		struct evlist_test e;
 		char name[MAX_NAME];
 
-		if (!strcmp(ent->d_name, ".") ||
-		    !strcmp(ent->d_name, ".."))
+		/* Names containing . are special and cannot be used directly */
+		if (strchr(ent->d_name, '.'))
 			continue;
 
 		snprintf(name, MAX_NAME, "cpu/event=%s/u", ent->d_name);
Signature · 1 line
2.5.5
author maintainer
#6 lore raw

PATCH 6/11 perf stat: Basic support for TopDown in perf stat

In reply to Arnaldo Carvalho de Melo

From: Andi Kleen <[email protected]>

Add basic plumbing for TopDown in perf stat

TopDown is intended to replace the frontend cycles idle/ backend cycles idle metrics in standard perf stat output. These metrics are not reliable in many workloads, due to out of order effects.

This implements a new --topdown mode in perf stat (similar to --transaction) that measures the pipe line bottlenecks using standardized formulas. The measurement can be all done with 5 counters (one fixed counter)

The result are four metrics:

FrontendBound, BackendBound, BadSpeculation, Retiring

that describe the CPU pipeline behavior on a high level.

The full top down methology has many hierarchical metrics. This implementation only supports level 1 which can be collected without multiplexing. A full implementation of top down on top of perf is available in pmu-tools toplev. (http://github.com/andikleen/pmu-tools)

The current version works on Intel Core CPUs starting with Sandy Bridge, and Atom CPUs starting with Silvermont. In principle the generic metrics should be also implementable on other out of order CPUs.

TopDown level 1 uses a set of abstracted metrics which are generic to out of order CPU cores (although some CPUs may not implement all of them):

  topdown-total-slots       Available slots in the pipeline
  topdown-slots-issued      Slots issued into the pipeline
  topdown-slots-retired     Slots successfully retired
  topdown-fetch-bubbles     Pipeline gaps in the frontend
  topdown-recovery-bubbles  Pipeline gaps during recovery

from misspeculation

These metrics then allow to compute four useful metrics:

FrontendBound, BackendBound, Retiring, BadSpeculation.

Add a new --topdown options to enable events. When --topdown is specified set up events for all topdown events supported by the kernel. Add topdown-* as a special case to the event parser, as is needed for all events containing -.

The actual code to compute the metrics is in follow-on patches.

v2: Use standard sysctl read function.
v3: Move x86 specific code to arch/
v4: Enable --metric-only implicitly for topdown.
v5: Add --single-thread option to not force per core mode
v6: Fix output order of topdown metrics
v7: Allow combining with -d
v8: Remove --single-thread again
v9: Rename functions, adding arch_ and topdown_.
v10: Expand man page and describe TopDown better Paste intro into commit description.
Print error when malloc fails.

---
 tools/perf/Documentation/perf-stat.txt |  32 +++++++++
 tools/perf/arch/x86/util/Build         |   1 +
 tools/perf/arch/x86/util/group.c       |  27 ++++++++
 tools/perf/builtin-stat.c              | 119 ++++++++++++++++++++++++++++++++-
 tools/perf/util/group.h                |   7 ++
 tools/perf/util/parse-events.l         |   1 +
 6 files changed, 184 insertions(+), 3 deletions(-)
 create mode 100644 tools/perf/arch/x86/util/group.c
 create mode 100644 tools/perf/util/group.h
tools/perf/Documentation/perf-stat.txt +32 -0
index 04f23b404bbc..d96ccd4844df 100644
@@ -204,6 +204,38 @@ Aggregate counts per physical processor for system-wide mode measurements.
 --no-aggr::
 Do not aggregate counts across all monitored CPUs.
 
+--topdown::
+Print top down level 1 metrics if supported by the CPU. This allows to
+determine bottle necks in the CPU pipeline for CPU bound workloads,
+by breaking the cycles consumed down into frontend bound, backend bound,
+bad speculation and retiring.
+
+Frontend bound means that the CPU cannot fetch and decode instructions fast
+enough. Backend bound means that computation or memory access is the bottle
+neck. Bad Speculation means that the CPU wasted cycles due to branch
+mispredictions and similar issues. Retiring means that the CPU computed without
+an apparently bottleneck. The bottleneck is only the real bottleneck
+if the workload is actually bound by the CPU and not by something else.
+
+For best results it is usually a good idea to use it with interval
+mode like -I 1000, as the bottleneck of workloads can change often.
+
+The top down metrics are collected per core instead of per
+CPU thread. Per core mode is automatically enabled
+and -a (global monitoring) is needed, requiring root rights or
+perf.perf_event_paranoid=-1.
+
+Topdown uses the full Performance Monitoring Unit, and needs
+disabling of the NMI watchdog (as root):
+echo 0 > /proc/sys/kernel/nmi_watchdog
+for best results. Otherwise the bottlenecks may be inconsistent
+on workload with changing phases.
+
+This enables --metric-only, unless overriden with --no-metric-only.
+
+To interpret the results it is usually needed to know on which
+CPUs the workload runs on. If needed the CPUs can be forced using
+taskset.
 
 EXAMPLES
 --------
tools/perf/arch/x86/util/Build +1 -0
index 465970370f3e..4cd8a16b1b7b 100644
@@ -3,6 +3,7 @@ libperf-y += tsc.o
 libperf-y += pmu.o
 libperf-y += kvm-stat.o
 libperf-y += perf_regs.o
+libperf-y += group.o
 
 libperf-$(CONFIG_DWARF) += dwarf-regs.o
 libperf-$(CONFIG_BPF_PROLOGUE) += dwarf-regs.o
tools/perf/arch/x86/util/group.c new file +27 -0
new file mode 100644
index 000000000000..37f92aa39a5d
@@ -0,0 +1,27 @@
+#include <stdio.h>
+#include "api/fs/fs.h"
+#include "util/group.h"
+
+/*
+ * Check whether we can use a group for top down.
+ * Without a group may get bad results due to multiplexing.
+ */
+bool arch_topdown_check_group(bool *warn)
+{
+	int n;
+
+	if (sysctl__read_int("kernel/nmi_watchdog", &n) < 0)
+		return false;
+	if (n > 0) {
+		*warn = true;
+		return false;
+	}
+	return true;
+}
+
+void arch_topdown_group_warn(void)
+{
+	fprintf(stderr,
+		"nmi_watchdog enabled with topdown. May give wrong results.\n"
+		"Disable with echo 0 > /proc/sys/kernel/nmi_watchdog\n");
+}
tools/perf/builtin-stat.c +116 -3

183 lines not on this page · raw message

tools/perf/util/group.h new file +7 -0
new file mode 100644
index 000000000000..116debe7a995
@@ -0,0 +1,7 @@
+#ifndef GROUP_H
+#define GROUP_H 1
+
+bool arch_topdown_check_group(bool *warn);
+void arch_topdown_group_warn(void);
+
+#endif
tools/perf/util/parse-events.l +1 -0
index 01af1ee90a27..3c15b33b2e84 100644
@@ -260,6 +260,7 @@ cycles-ct					{ return str(yyscanner, PE_KERNEL_PMU_EVENT); }
 cycles-t					{ return str(yyscanner, PE_KERNEL_PMU_EVENT); }
 mem-loads					{ return str(yyscanner, PE_KERNEL_PMU_EVENT); }
 mem-stores					{ return str(yyscanner, PE_KERNEL_PMU_EVENT); }
+topdown-[a-z-]+					{ return str(yyscanner, PE_KERNEL_PMU_EVENT); }
 
 L1-dcache|l1-d|l1d|L1-data		|
 L1-icache|l1-i|l1i|L1-instruction	|
Signature · 1 line
2.5.5
author maintainer
#7 lore raw

PATCH 7/11 perf stat: Add computation of TopDown formulas

In reply to Arnaldo Carvalho de Melo

From: Andi Kleen <[email protected]>

Implement the TopDown formulas in 'perf stat'. The topdown basic metrics reported by the kernel are collected, and the formulas are computed and output as normal metrics.

See the kernel commit exporting the events for details on the used metrics.

Committer note:

Output example:

  # perf stat --topdown -a usleep 1

Performance counter stats for 'system wide':

retiring bad speculation frontend bound backend bound

  S0-C0    2     23.8%       11.6%            28.3%           36.3%
  S0-C1    2     16.2%       15.7%            36.5%           31.6%
         0.000579956 seconds time elapsed

#

v2: Always print all metrics, only use thresholds for coloring.
v3: Mark retiring over threshold green, not red.
v4: Only print one decimal digit
Fix color printing of one metric
v5: Avoid printing -0.0
v6: Remove extra frontend event lookup

---
 tools/perf/util/stat-shadow.c | 162 ++++++++++++++++++++++++++++++++++++++++++
 tools/perf/util/stat.c        |   5 ++
 tools/perf/util/stat.h        |   5 ++
 3 files changed, 172 insertions(+)
tools/perf/util/stat-shadow.c +162 -0
index aa9efe08762b..8a2bbd2a4d82 100644
@@ -36,6 +36,11 @@ static struct stats runtime_dtlb_cache_stats[NUM_CTX][MAX_NR_CPUS];
 static struct stats runtime_cycles_in_tx_stats[NUM_CTX][MAX_NR_CPUS];
 static struct stats runtime_transaction_stats[NUM_CTX][MAX_NR_CPUS];
 static struct stats runtime_elision_stats[NUM_CTX][MAX_NR_CPUS];
+static struct stats runtime_topdown_total_slots[NUM_CTX][MAX_NR_CPUS];
+static struct stats runtime_topdown_slots_issued[NUM_CTX][MAX_NR_CPUS];
+static struct stats runtime_topdown_slots_retired[NUM_CTX][MAX_NR_CPUS];
+static struct stats runtime_topdown_fetch_bubbles[NUM_CTX][MAX_NR_CPUS];
+static struct stats runtime_topdown_recovery_bubbles[NUM_CTX][MAX_NR_CPUS];
 static bool have_frontend_stalled;
 
 struct stats walltime_nsecs_stats;
@@ -82,6 +87,11 @@ void perf_stat__reset_shadow_stats(void)
 		sizeof(runtime_transaction_stats));
 	memset(runtime_elision_stats, 0, sizeof(runtime_elision_stats));
 	memset(&walltime_nsecs_stats, 0, sizeof(walltime_nsecs_stats));
+	memset(runtime_topdown_total_slots, 0, sizeof(runtime_topdown_total_slots));
+	memset(runtime_topdown_slots_retired, 0, sizeof(runtime_topdown_slots_retired));
+	memset(runtime_topdown_slots_issued, 0, sizeof(runtime_topdown_slots_issued));
+	memset(runtime_topdown_fetch_bubbles, 0, sizeof(runtime_topdown_fetch_bubbles));
+	memset(runtime_topdown_recovery_bubbles, 0, sizeof(runtime_topdown_recovery_bubbles));
 }
 
 /*
@@ -105,6 +115,16 @@ void perf_stat__update_shadow_stats(struct perf_evsel *counter, u64 *count,
 		update_stats(&runtime_transaction_stats[ctx][cpu], count[0]);
 	else if (perf_stat_evsel__is(counter, ELISION_START))
 		update_stats(&runtime_elision_stats[ctx][cpu], count[0]);
+	else if (perf_stat_evsel__is(counter, TOPDOWN_TOTAL_SLOTS))
+		update_stats(&runtime_topdown_total_slots[ctx][cpu], count[0]);
+	else if (perf_stat_evsel__is(counter, TOPDOWN_SLOTS_ISSUED))
+		update_stats(&runtime_topdown_slots_issued[ctx][cpu], count[0]);
+	else if (perf_stat_evsel__is(counter, TOPDOWN_SLOTS_RETIRED))
+		update_stats(&runtime_topdown_slots_retired[ctx][cpu], count[0]);
+	else if (perf_stat_evsel__is(counter, TOPDOWN_FETCH_BUBBLES))
+		update_stats(&runtime_topdown_fetch_bubbles[ctx][cpu],count[0]);
+	else if (perf_stat_evsel__is(counter, TOPDOWN_RECOVERY_BUBBLES))
+		update_stats(&runtime_topdown_recovery_bubbles[ctx][cpu], count[0]);
 	else if (perf_evsel__match(counter, HARDWARE, HW_STALLED_CYCLES_FRONTEND))
 		update_stats(&runtime_stalled_cycles_front_stats[ctx][cpu], count[0]);
 	else if (perf_evsel__match(counter, HARDWARE, HW_STALLED_CYCLES_BACKEND))
@@ -302,6 +322,107 @@ static void print_ll_cache_misses(int cpu,
 	out->print_metric(out->ctx, color, "%7.2f%%", "of all LL-cache hits", ratio);
 }
 
+/*
+ * High level "TopDown" CPU core pipe line bottleneck break down.
+ *
+ * Basic concept following
+ * Yasin, A Top Down Method for Performance analysis and Counter architecture
+ * ISPASS14
+ *
+ * The CPU pipeline is divided into 4 areas that can be bottlenecks:
+ *
+ * Frontend -> Backend -> Retiring
+ * BadSpeculation in addition means out of order execution that is thrown away
+ * (for example branch mispredictions)
+ * Frontend is instruction decoding.
+ * Backend is execution, like computation and accessing data in memory
+ * Retiring is good execution that is not directly bottlenecked
+ *
+ * The formulas are computed in slots.
+ * A slot is an entry in the pipeline each for the pipeline width
+ * (for example a 4-wide pipeline has 4 slots for each cycle)
+ *
+ * Formulas:
+ * BadSpeculation = ((SlotsIssued - SlotsRetired) + RecoveryBubbles) /
+ *			TotalSlots
+ * Retiring = SlotsRetired / TotalSlots
+ * FrontendBound = FetchBubbles / TotalSlots
+ * BackendBound = 1.0 - BadSpeculation - Retiring - FrontendBound
+ *
+ * The kernel provides the mapping to the low level CPU events and any scaling
+ * needed for the CPU pipeline width, for example:
+ *
+ * TotalSlots = Cycles * 4
+ *
+ * The scaling factor is communicated in the sysfs unit.
+ *
+ * In some cases the CPU may not be able to measure all the formulas due to
+ * missing events. In this case multiple formulas are combined, as possible.
+ *
+ * Full TopDown supports more levels to sub-divide each area: for example
+ * BackendBound into computing bound and memory bound. For now we only
+ * support Level 1 TopDown.
+ */
+
+static double sanitize_val(double x)
+{
+	if (x < 0 && x >= -0.02)
+		return 0.0;
+	return x;
+}
+
+static double td_total_slots(int ctx, int cpu)
+{
+	return avg_stats(&runtime_topdown_total_slots[ctx][cpu]);
+}
+
+static double td_bad_spec(int ctx, int cpu)
+{
+	double bad_spec = 0;
+	double total_slots;
+	double total;
+
+	total = avg_stats(&runtime_topdown_slots_issued[ctx][cpu]) -
+		avg_stats(&runtime_topdown_slots_retired[ctx][cpu]) +
+		avg_stats(&runtime_topdown_recovery_bubbles[ctx][cpu]);
+	total_slots = td_total_slots(ctx, cpu);
+	if (total_slots)
+		bad_spec = total / total_slots;
+	return sanitize_val(bad_spec);
+}
+
+static double td_retiring(int ctx, int cpu)
+{
+	double retiring = 0;
+	double total_slots = td_total_slots(ctx, cpu);
+	double ret_slots = avg_stats(&runtime_topdown_slots_retired[ctx][cpu]);
+
+	if (total_slots)
+		retiring = ret_slots / total_slots;
+	return retiring;
+}
+
+static double td_fe_bound(int ctx, int cpu)
+{
+	double fe_bound = 0;
+	double total_slots = td_total_slots(ctx, cpu);
+	double fetch_bub = avg_stats(&runtime_topdown_fetch_bubbles[ctx][cpu]);
+
+	if (total_slots)
+		fe_bound = fetch_bub / total_slots;
+	return fe_bound;
+}
+
+static double td_be_bound(int ctx, int cpu)
+{
+	double sum = (td_fe_bound(ctx, cpu) +
+		      td_bad_spec(ctx, cpu) +
+		      td_retiring(ctx, cpu));
+	if (sum == 0)
+		return 0;
+	return sanitize_val(1.0 - sum);
+}
+
 void perf_stat__print_shadow_stats(struct perf_evsel *evsel,
 				   double avg, int cpu,
 				   struct perf_stat_output_ctx *out)
@@ -309,6 +430,7 @@ void perf_stat__print_shadow_stats(struct perf_evsel *evsel,
 	void *ctxp = out->ctx;
 	print_metric_t print_metric = out->print_metric;
 	double total, ratio = 0.0, total2;
+	const char *color = NULL;
 	int ctx = evsel_context(evsel);
 
 	if (perf_evsel__match(evsel, HARDWARE, HW_INSTRUCTIONS)) {
@@ -452,6 +574,46 @@ void perf_stat__print_shadow_stats(struct perf_evsel *evsel,
 				     avg / ratio);
 		else
 			print_metric(ctxp, NULL, NULL, "CPUs utilized", 0);
+	} else if (perf_stat_evsel__is(evsel, TOPDOWN_FETCH_BUBBLES)) {
+		double fe_bound = td_fe_bound(ctx, cpu);
+
+		if (fe_bound > 0.2)
+			color = PERF_COLOR_RED;
+		print_metric(ctxp, color, "%8.1f%%", "frontend bound",
+				fe_bound * 100.);
+	} else if (perf_stat_evsel__is(evsel, TOPDOWN_SLOTS_RETIRED)) {
+		double retiring = td_retiring(ctx, cpu);
+
+		if (retiring > 0.7)
+			color = PERF_COLOR_GREEN;
+		print_metric(ctxp, color, "%8.1f%%", "retiring",
+				retiring * 100.);
+	} else if (perf_stat_evsel__is(evsel, TOPDOWN_RECOVERY_BUBBLES)) {
+		double bad_spec = td_bad_spec(ctx, cpu);
+
+		if (bad_spec > 0.1)
+			color = PERF_COLOR_RED;
+		print_metric(ctxp, color, "%8.1f%%", "bad speculation",
+				bad_spec * 100.);
+	} else if (perf_stat_evsel__is(evsel, TOPDOWN_SLOTS_ISSUED)) {
+		double be_bound = td_be_bound(ctx, cpu);
+		const char *name = "backend bound";
+		static int have_recovery_bubbles = -1;
+
+		/* In case the CPU does not support topdown-recovery-bubbles */
+		if (have_recovery_bubbles < 0)
+			have_recovery_bubbles = pmu_have_event("cpu",
+					"topdown-recovery-bubbles");
+		if (!have_recovery_bubbles)
+			name = "backend bound/bad spec";
+
+		if (be_bound > 0.2)
+			color = PERF_COLOR_RED;
+		if (td_total_slots(ctx, cpu) > 0)
+			print_metric(ctxp, color, "%8.1f%%", name,
+					be_bound * 100.);
+		else
+			print_metric(ctxp, NULL, NULL, name, 0);
 	} else if (runtime_nsecs_stats[cpu].n != 0) {
 		char unit = 'M';
 		char unit_buf[10];
tools/perf/util/stat.c +5 -0
index ffa1d0653861..c1ba255f2abe 100644
@@ -79,6 +79,11 @@ static const char *id_str[PERF_STAT_EVSEL_ID__MAX] = {
 	ID(TRANSACTION_START,	cpu/tx-start/),
 	ID(ELISION_START,	cpu/el-start/),
 	ID(CYCLES_IN_TX_CP,	cpu/cycles-ct/),
+	ID(TOPDOWN_TOTAL_SLOTS, topdown-total-slots),
+	ID(TOPDOWN_SLOTS_ISSUED, topdown-slots-issued),
+	ID(TOPDOWN_SLOTS_RETIRED, topdown-slots-retired),
+	ID(TOPDOWN_FETCH_BUBBLES, topdown-fetch-bubbles),
+	ID(TOPDOWN_RECOVERY_BUBBLES, topdown-recovery-bubbles),
 };
 #undef ID
 
tools/perf/util/stat.h +5 -0
index 0150e786ccc7..c29bb94c48a4 100644
@@ -17,6 +17,11 @@ enum perf_stat_evsel_id {
 	PERF_STAT_EVSEL_ID__TRANSACTION_START,
 	PERF_STAT_EVSEL_ID__ELISION_START,
 	PERF_STAT_EVSEL_ID__CYCLES_IN_TX_CP,
+	PERF_STAT_EVSEL_ID__TOPDOWN_TOTAL_SLOTS,
+	PERF_STAT_EVSEL_ID__TOPDOWN_SLOTS_ISSUED,
+	PERF_STAT_EVSEL_ID__TOPDOWN_SLOTS_RETIRED,
+	PERF_STAT_EVSEL_ID__TOPDOWN_FETCH_BUBBLES,
+	PERF_STAT_EVSEL_ID__TOPDOWN_RECOVERY_BUBBLES,
 	PERF_STAT_EVSEL_ID__MAX,
 };
 
Signature · 1 line
2.5.5
author maintainer
#8 lore raw

PATCH 8/11 perf stat: Print topology/time headers with --metric-only

In reply to Arnaldo Carvalho de Melo

From: Andi Kleen <[email protected]>

When --metric-only is enabled there were no headers for the topology in interval mode. Also when headers were printed they were on a separate line.

Before:

  $ perf stat  --metric-only  -A -I 1000 -a
    1.001038376     frontend cycles idle insn per cycle  stalled cycles per insn branch-misses of all branches
    1.001038376 CPU0   123.54%               0.23           5.29                    7.61%
    1.001038376 CPU1   137.78%               0.24           5.13                   10.07%
    1.001038376 CPU2    64.48%               0.22           5.50                    6.84%

After:

  $ perf stat  --metric-only  -A -I 1000 -a
    1.001111114 CPU0    82.46%               0.32           2.60                    7.64%
    1.001111114 CPU1   126.63%               0.02          42.83                    0.15%
    1.001111114 CPU2   193.54%               0.32           2.59                    6.92%

v2: Move all headers on a single line

---
 tools/perf/builtin-stat.c | 32 ++++++++++++++++++++++----------
 1 file changed, 22 insertions(+), 10 deletions(-)
tools/perf/builtin-stat.c +22 -10
index fd76bb0b18d1..a168e726756b 100644
@@ -1316,7 +1316,7 @@ static int aggr_header_lens[] = {
 	[AGGR_GLOBAL] = 0,
 };
 
-static void print_metric_headers(char *prefix)
+static void print_metric_headers(const char *prefix, bool no_indent)
 {
 	struct perf_stat_output_ctx out;
 	struct perf_evsel *counter;
@@ -1327,7 +1327,7 @@ static void print_metric_headers(char *prefix)
 	if (prefix)
 		fprintf(stat_config.output, "%s", prefix);
 
-	if (!csv_output)
+	if (!csv_output && !no_indent)
 		fprintf(stat_config.output, "%*s",
 			aggr_header_lens[stat_config.aggr_mode], "");
 
@@ -1352,28 +1352,40 @@ static void print_interval(char *prefix, struct timespec *ts)
 
 	sprintf(prefix, "%6lu.%09lu%s", ts->tv_sec, ts->tv_nsec, csv_sep);
 
-	if (num_print_interval == 0 && !csv_output && !metric_only) {
+	if (num_print_interval == 0 && !csv_output) {
 		switch (stat_config.aggr_mode) {
 		case AGGR_SOCKET:
-			fprintf(output, "#           time socket cpus             counts %*s events\n", unit_width, "unit");
+			fprintf(output, "#           time socket cpus");
+			if (!metric_only)
+				fprintf(output, "             counts %*s events\n", unit_width, "unit");
 			break;
 		case AGGR_CORE:
-			fprintf(output, "#           time core         cpus             counts %*s events\n", unit_width, "unit");
+			fprintf(output, "#           time core         cpus");
+			if (!metric_only)
+				fprintf(output, "             counts %*s events\n", unit_width, "unit");
 			break;
 		case AGGR_NONE:
-			fprintf(output, "#           time CPU                counts %*s events\n", unit_width, "unit");
+			fprintf(output, "#           time CPU");
+			if (!metric_only)
+				fprintf(output, "                counts %*s events\n", unit_width, "unit");
 			break;
 		case AGGR_THREAD:
-			fprintf(output, "#           time             comm-pid                  counts %*s events\n", unit_width, "unit");
+			fprintf(output, "#           time             comm-pid");
+			if (!metric_only)
+				fprintf(output, "                  counts %*s events\n", unit_width, "unit");
 			break;
 		case AGGR_GLOBAL:
 		default:
-			fprintf(output, "#           time             counts %*s events\n", unit_width, "unit");
+			fprintf(output, "#           time");
+			if (!metric_only)
+				fprintf(output, "             counts %*s events\n", unit_width, "unit");
 		case AGGR_UNSET:
 			break;
 		}
 	}
 
+	if (num_print_interval == 0 && metric_only)
+		print_metric_headers(" ", true);
 	if (++num_print_interval == 25)
 		num_print_interval = 0;
 }
@@ -1442,8 +1454,8 @@ static void print_counters(struct timespec *ts, int argc, const char **argv)
 	if (metric_only) {
 		static int num_print_iv;
 
-		if (num_print_iv == 0)
-			print_metric_headers(prefix);
+		if (num_print_iv == 0 && !interval)
+			print_metric_headers(prefix, false);
 		if (num_print_iv++ == 25)
 			num_print_iv = 0;
 		if (stat_config.aggr_mode == AGGR_GLOBAL && prefix)
Signature · 1 line
2.5.5
author maintainer
#9 lore raw

PATCH 9/11 perf stat: Add missing aggregation headers for --metric-only CSV

In reply to Arnaldo Carvalho de Melo

From: Andi Kleen <[email protected]>

When in CSV mode --metric-only outputs an header, unlike the other modes. Previously it did not properly print headers for the aggregation columns, so the headers were actually shifted against the real values.

Fix this here by outputting the correct headers for CSV.

v2: Indent array.

---
 tools/perf/builtin-stat.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)
tools/perf/builtin-stat.c +14 -0
index a168e726756b..dff63733dfb7 100644
@@ -1316,6 +1316,14 @@ static int aggr_header_lens[] = {
 	[AGGR_GLOBAL] = 0,
 };
 
+static const char *aggr_header_csv[] = {
+	[AGGR_CORE] 	= 	"core,cpus,",
+	[AGGR_SOCKET] 	= 	"socket,cpus",
+	[AGGR_NONE] 	= 	"cpu,",
+	[AGGR_THREAD] 	= 	"comm-pid,",
+	[AGGR_GLOBAL] 	=	""
+};
+
 static void print_metric_headers(const char *prefix, bool no_indent)
 {
 	struct perf_stat_output_ctx out;
@@ -1330,6 +1338,12 @@ static void print_metric_headers(const char *prefix, bool no_indent)
 	if (!csv_output && !no_indent)
 		fprintf(stat_config.output, "%*s",
 			aggr_header_lens[stat_config.aggr_mode], "");
+	if (csv_output) {
+		if (stat_config.interval)
+			fputs("time,", stat_config.output);
+		fputs(aggr_header_csv[stat_config.aggr_mode],
+			stat_config.output);
+	}
 
 	/* Print metrics headers only */
 	evlist__for_each(evsel_list, counter) {
Signature · 1 line
2.5.5
author maintainer
#10 lore raw

PATCH 10/11 perf config: Fix abnormal termination at perf_parse_file()

In reply to Arnaldo Carvalho de Melo

From: Taeung Song <[email protected]>

If a config file has wrong key-value pairs, the perf process will be forcibly terminated by die() at perf_parse_file() called by perf_config() so terminal settings can be crushed because of unusual termination.

For example:

If user config file has a wrong value 'red;default' instead of a normal value like 'red, default' for a key 'colors.top',

    # cat ~/.perfconfig
    [colors]
        medium = red;default # wrong value

and if running sub-command 'top',

    # perf top

perf process is dead by force and terminal setting is broken with a messge like below.

Fatal: bad config file line 2 in /root/.perfconfig

So fix it.
If perf_config() can return on failure without calling die() at perf_parse_file(), this problem can be solved.
And if a config file has wrong values, show the error message and then use default config values instead of wrong config values.

---
 tools/perf/util/config.c | 16 +++++++---------
 1 file changed, 7 insertions(+), 9 deletions(-)
tools/perf/util/config.c +7 -9
index dad7d8272168..b50073741b80 100644
@@ -275,7 +275,8 @@ static int perf_parse_file(config_fn_t fn, void *data)
 			break;
 		}
 	}
-	die("bad config file line %d in %s", config_linenr, config_file_name);
+	pr_err("bad config file line %d in %s\n", config_linenr, config_file_name);
+	return -1;
 }
 
 static int parse_unit_factor(const char *end, unsigned long *val)
@@ -479,16 +480,15 @@ static int perf_config_global(void)
 
 int perf_config(config_fn_t fn, void *data)
 {
-	int ret = 0, found = 0;
+	int ret = -1;
 	const char *home = NULL;
 
 	/* Setting $PERF_CONFIG makes perf read _only_ the given config file. */
 	if (config_exclusive_filename)
 		return perf_config_from_file(fn, config_exclusive_filename, data);
 	if (perf_config_system() && !access(perf_etc_perfconfig(), R_OK)) {
-		ret += perf_config_from_file(fn, perf_etc_perfconfig(),
-					    data);
-		found += 1;
+		if (perf_config_from_file(fn, perf_etc_perfconfig(), data) < 0)
+			goto out;
 	}
 
 	home = getenv("HOME");
@@ -514,14 +514,12 @@ int perf_config(config_fn_t fn, void *data)
 		if (!st.st_size)
 			goto out_free;
 
-		ret += perf_config_from_file(fn, user_config, data);
-		found += 1;
+		ret = perf_config_from_file(fn, user_config, data);
+
 out_free:
 		free(user_config);
 	}
 out:
-	if (found == 0)
-		return -1;
 	return ret;
 }
 
Signature · 1 line
2.5.5
author maintainer
#11 lore raw

PATCH 11/11 perf config: Handle the error when config set is NULL at collect_config()

In reply to Arnaldo Carvalho de Melo

From: Taeung Song <[email protected]>

collect_config() collect all config key-value pairs from config files and put each config info in config set. But if config set (i.e. 'set' variable at collect_config()) is NULL, this is wrong so handle it.

---
 tools/perf/util/config.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)
tools/perf/util/config.c +5 -1
index b50073741b80..c73f1c4d1ca9 100644
@@ -607,8 +607,12 @@ static int collect_config(const char *var, const char *value,
 	struct perf_config_section *section = NULL;
 	struct perf_config_item *item = NULL;
 	struct perf_config_set *set = perf_config_set;
-	struct list_head *sections = &set->sections;
+	struct list_head *sections;
 
+	if (set == NULL)
+		return -1;
+
+	sections = &set->sections;
 	key = ptr = strdup(var);
 	if (!key) {
 		pr_debug("%s: strdup failed\n", __func__);
Signature · 1 line
2.5.5
#12 lore raw
In reply to Arnaldo Carvalho de Melo
Quoted 76 lines · Arnaldo Carvalho de Melo

Hi Ingo,

Please consider pulling,

- Arnaldo

The following changes since commit 030ba6cd105c68ce919c5e239853b567490cd059:

perf/x86/intel: Use new topology_max_smt_threads() in HT leak workaround (2016-06-03 09:41:25 +0200)

are available in the git repository at:

git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git tags/perf-core-for-mingo-20160606

for you to fetch changes up to 7db91f251056f90fec4121f028680ab3153a0f3c:

perf config: Handle the error when config set is NULL at collect_config() (2016-06-06 17:43:19 -0300)

----------------------------------------------------------------
perf/core improvements and fixes:

User visible:

- Tooling support for TopDown counters, recently added to the kernel (Andi Kleen)

- Show call graphs in 'perf script' when 1st event doesn't have it but some other has (He Kuang)

- Fix terminal cleanup when handling invalid .perfconfig files in 'perf top' (Taeung Song)

Build fixes:

- Respect CROSS_COMPILE for the linker in libapi (Lucas Stach)

Infrastructure:

- Fix perf_evlist__alloc_mmap() failure path (Wang Nan)

- Provide way to extract integer value from format_field (Arnaldo Carvalho de Melo)

----------------------------------------------------------------
Andi Kleen (5):
perf test: Ignore .scale and other special files
perf stat: Basic support for TopDown in perf stat perf stat: Add computation of TopDown formulas
perf stat: Print topology/time headers with --metric-only perf stat: Add missing aggregation headers for --metric-only CSV

Arnaldo Carvalho de Melo (1):
perf evsel: Provide way to extract integer value from format_field

He Kuang (1):
perf script: Show call graphs when 1st event doesn't have it but some other has

Lucas Stach (1):
tools lib api: Respect CROSS_COMPILE for the linker

Taeung Song (2):
perf config: Fix abnormal termination at perf_parse_file() perf config: Handle the error when config set is NULL at collect_config()

Wang Nan (1):
perf evlist: Fix alloc_mmap() failure path

 tools/lib/api/Makefile                 |   1 +
 tools/perf/Documentation/perf-stat.txt |  32 +++++++
 tools/perf/arch/x86/util/Build         |   1 +
 tools/perf/arch/x86/util/group.c       |  27 ++++++
 tools/perf/builtin-script.c            |  23 +++--
 tools/perf/builtin-stat.c              | 165 ++++++++++++++++++++++++++++++---
 tools/perf/tests/parse-events.c        |   4 +-
 tools/perf/util/config.c               |  22 +++--
 tools/perf/util/evlist.c               |   5 +-
 tools/perf/util/evsel.c                |  25 +++--
 tools/perf/util/evsel.h                |   2 +
Quoted 8 lines
 tools/perf/util/group.h                |   7 ++
 tools/perf/util/parse-events.l         |   1 +
 tools/perf/util/stat-shadow.c          | 162 ++++++++++++++++++++++++++++++++
 tools/perf/util/stat.c                 |   5 +
 tools/perf/util/stat.h                 |   5 +
 16 files changed, 441 insertions(+), 46 deletions(-)
 create mode 100644 tools/perf/arch/x86/util/group.c
 create mode 100644 tools/perf/util/group.h

Pulled, thanks a lot Arnaldo!

Ingo