When recently using 'perf report --stat' it was not clear to me from the
output whether a particular statistics field (LOST_SAMPLES) was not
present, or just zero:
fomalhaut:~> perf report --stat
Aggregated stats:
TOTAL events: 495984
MMAP events: 85
COMM events: 3389
EXIT events: 1605
THROTTLE events: 2
UNTHROTTLE events: 2
FORK events: 3377
SAMPLE events: 472629
MMAP2 events: 14753
FINISHED_ROUND events: 139
THREAD_MAP events: 1
CPU_MAP events: 1
TIME_CONV events: 1
I had to check the output several times to ascertain that I'm not
misreading the output, that the field didn't change and that I didn't
misremember the name. In fact I had to look into the perf source to make
sure that zero fields are indeed not shown.
With the patch applied:
fomalhaut:~> perf report --stat
Aggregated stats:
TOTAL events: 495984
MMAP events: 85
LOST events: 0
COMM events: 3389
EXIT events: 1605
THROTTLE events: 2
UNTHROTTLE events: 2
FORK events: 3377
READ events: 0
SAMPLE events: 472629
MMAP2 events: 14753
AUX events: 0
ITRACE_START events: 0
LOST_SAMPLES events: 0
SWITCH events: 0
SWITCH_CPU_WIDE events: 0
NAMESPACES events: 0
ATTR events: 0
EVENT_TYPE events: 0
TRACING_DATA events: 0
BUILD_ID events: 0
FINISHED_ROUND events: 139
ID_INDEX events: 0
AUXTRACE_INFO events: 0
AUXTRACE events: 0
AUXTRACE_ERROR events: 0
THREAD_MAP events: 1
CPU_MAP events: 1
STAT_CONFIG events: 0
STAT events: 0
STAT_ROUND events: 0
EVENT_UPDATE events: 0
TIME_CONV events: 1
FEATURE events: 0
It's pretty clear at a glance that LOST_SAMPLES is present but zero.
The original output can still be gotten via:
fomalhaut:~> perf report --stat | grep -vw 0
Aggregated stats:
TOTAL events: 495984
MMAP events: 85
COMM events: 3389
EXIT events: 1605
THROTTLE events: 2
UNTHROTTLE events: 2
FORK events: 3377
SAMPLE events: 472629
MMAP2 events: 14753
FINISHED_ROUND events: 139
THREAD_MAP events: 1
CPU_MAP events: 1
TIME_CONV events: 1
So I don't think there's any real loss in functionality.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/20180307152430.7e5h7e657b7bgd7q@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Executing command 'perf stat -T -- ls' dumps core on x86 and s390.
Here is the call back chain (done on x86):
# gdb ./perf
....
(gdb) r stat -T -- ls
...
Program received signal SIGSEGV, Segmentation fault.
0x00007ffff56d1963 in vasprintf () from /lib64/libc.so.6
(gdb) where
#0 0x00007ffff56d1963 in vasprintf () from /lib64/libc.so.6
#1 0x00007ffff56ae484 in asprintf () from /lib64/libc.so.6
#2 0x00000000004f1982 in __parse_events_add_pmu (parse_state=0x7fffffffd580,
list=0xbfb970, name=0xbf3ef0 "cpu",
head_config=0xbfb930, auto_merge_stats=false) at util/parse-events.c:1233
#3 0x00000000004f1c8e in parse_events_add_pmu (parse_state=0x7fffffffd580,
list=0xbfb970, name=0xbf3ef0 "cpu",
head_config=0xbfb930) at util/parse-events.c:1288
#4 0x0000000000537ce3 in parse_events_parse (_parse_state=0x7fffffffd580,
scanner=0xbf4210) at util/parse-events.y:234
#5 0x00000000004f2c7a in parse_events__scanner (str=0x6b66c0
"task-clock,{instructions,cycles,cpu/cycles-t/,cpu/tx-start/}",
parse_state=0x7fffffffd580, start_token=258) at util/parse-events.c:1673
#6 0x00000000004f2e23 in parse_events (evlist=0xbe9990, str=0x6b66c0
"task-clock,{instructions,cycles,cpu/cycles-t/,cpu/tx-start/}", err=0x0)
at util/parse-events.c:1713
#7 0x000000000044e137 in add_default_attributes () at builtin-stat.c:2281
#8 0x000000000044f7b5 in cmd_stat (argc=1, argv=0x7fffffffe3b0) at
builtin-stat.c:2828
#9 0x00000000004c8b0f in run_builtin (p=0xab01a0 <commands+288>, argc=4,
argv=0x7fffffffe3b0) at perf.c:297
#10 0x00000000004c8d7c in handle_internal_command (argc=4,
argv=0x7fffffffe3b0) at perf.c:349
#11 0x00000000004c8ece in run_argv (argcp=0x7fffffffe20c,
argv=0x7fffffffe200) at perf.c:393
#12 0x00000000004c929c in main (argc=4, argv=0x7fffffffe3b0) at perf.c:537
(gdb)
It turns out that a NULL pointer is referenced. Here are the
function calls:
...
cmd_stat()
+---> add_default_attributes()
+---> parse_events(evsel_list, transaction_attrs, NULL);
3rd parameter set to NULL
Function parse_events(xx, xx, struct parse_events_error *err) dives
into a bison generated scanner and creates
parser state information for it first:
struct parse_events_state parse_state = {
.list = LIST_HEAD_INIT(parse_state.list),
.idx = evlist->nr_entries,
.error = err, <--- NULL POINTER !!!
.evlist = evlist,
};
Now various functions inside the bison scanner are called to end up in
__parse_events_add_pmu(struct parse_events_state *parse_state, ..) with
first parameter being a pointer to above structure definition.
Now the PMU event name is not found (because being executed in a VM) and
this function tries to create an error message with
asprintf(&parse_state->error.str, ....)
which references a NULL pointer and dumps core.
Fix this by providing a pointer to the necessary error information
instead of NULL. Technically only the else part is needed to avoid the
core dump, just lets be safe...
Signed-off-by: Thomas Richter <tmricht@linux.vnet.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Link: http://lkml.kernel.org/r/20180308145735.64717-1-tmricht@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
For some architectures (like arm), there are architecture- defined
events. Sometimes these events may be "recommended" according to the
architecture standard, in that the implementer is free ignore the
"recommendation" and create its custom event.
This patch adds support for parsing standard events from arch-defined
JSONs, and fixing up vendor events when they have implemented these
events as standard.
Support is also ensured that the vendor may implement their own custom
events.
A new step is added to the pmu events parsing to fix up the vendor
events with the arch-standard events.
The arch-defined JSONs must be placed in the arch root folder for
preprocessing prior to tree JSON processing.
In the vendor JSON, to specify that the arch event is supported, the
keyword "ArchStdEvent" should be used, like this:
[
{
"ArchStdEvent": "L1D_CACHE_WR",
},
]
Matching is based on the "EventName" field in the architecture JSON.
No other JSON objects are strictly required. However, for other objects
added, these take precedence over architecture defined standard events,
thus supporting separate events which have the same event code.
Signed-off-by: John Garry <john.garry@huawei.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ganapatrao Kulkarni <ganapatrao.kulkarni@cavium.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Shaokun Zhang <zhangshaokun@hisilicon.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: William Cohen <wcohen@redhat.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linuxarm@huawei.com
Link: http://lkml.kernel.org/r/1520506716-197429-8-git-send-email-john.garry@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
For some architectures (like arm), it is required to support a vendor
subdirectory and not locate all the JSONs for a specific vendor in the
same folder.
This is because all the events for the same vendor will be placed in the
same pmu events table, which may cause conflict. This conflict would be
in the instance that a vendor's custom implemented events do have the
same meaning on different platforms, so events in the pmu table would
conflict. In addition, per list command may show events which are not
even supported for a given platform.
This patch adds support for a arch/vendor/platform directory hierarchy,
while maintaining backwards-compatibility for existing arch/platform
structure. In this, each platform would always have its own pmu events
table.
In generated file pmu_events.c, each platform table name is in the
format pme{_vendor}_platform, like this:
struct pmu_events_map pmu_events_map[] = {
{
.cpuid = "0x00000000420f5160",
.version = "v1",
.type = "core",
.table = pme_cavium_thunderx2
},
{
.cpuid = 0,
.version = 0,
.type = 0,
.table = 0,
},
};
Signed-off-by: John Garry <john.garry@huawei.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ganapatrao Kulkarni <ganapatrao.kulkarni@cavium.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Shaokun Zhang <zhangshaokun@hisilicon.com>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: William Cohen <wcohen@redhat.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linuxarm@huawei.com
Link: http://lkml.kernel.org/r/1520506716-197429-5-git-send-email-john.garry@huawei.com
Link: http://lkml.kernel.org/r/1521047452-28565-1-git-send-email-john.garry@huawei.com
[ Add missing limits.h include, fixing the build on at least all Alpine Linux versions tested (3.4 to 3.7 + edge), ]
[ Applied a patch to fix reading ./.. directories in XFS, see second Link tag ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Adding the 'PA cnt' column grouped under data cacheline address.
It shows how many times the physical addresses changed for the hist
entry. It does not show the number of different physical addresses for
entry, because we don't store those. We only track the number of times
we got different address than we currently hold, which is not expensive
and gives similar info.
$ perf c2c report --stdio
# ----------- Cacheline ---------- Total Tot ----- LLC Load Hitm -----
# Index Address Node PA cnt records Hitm Total Lcl Rmt
# ..... .................. .... ...... ....... ....... ....... ....... .......
#
0 0xffff9ad56dca0a80 0 9 10 7.69% 2 2 0
1 0xffff9ad56dce0a80 0 9 9 7.69% 2 2 0
2 0xffff9ad37659ad80 0 1 2 3.85% 1 1 0
...
# ----- HITM ----- -- Store Refs -- --------- Data address ---------
# Num Rmt Lcl L1 Hit L1 Miss Offset Node PA cnt Pid
# ..... ....... ....... ....... ....... .................. .... ...... .......
#
-------------------------------------------------------------
0 0 2 3 0 0xffff9ad56dca0a80
-------------------------------------------------------------
0.00% 0.00% 33.33% 0.00% 0x0 0 1 2510
0.00% 0.00% 33.33% 0.00% 0x4 0 1 2476
0.00% 0.00% 33.33% 0.00% 0x20 0 1 0
0.00% 100.00% 0.00% 0.00% 0x38 0 1 0
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Joe Mario <jmario@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180309101442.9224-10-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Adding the NUMA node info for the data cacheline. Adding the new column
to both "Shared Data Cache Line Table" and "Shared Cache Line
Distribution Pareto".
Note the new 'Node' column next to the 'Cacheline'.
$ perf c2c report --stdio
=================================================
Shared Data Cache Line Table
=================================================
#
# Total Tot ----- LLC Load Hitm -----
# Index Cacheline Node records Hitm Total Lcl Rmt
# ..... .................. .... ....... ....... ....... ....... .......
#
0 0x7f0830100000 0 84 10.53% 8 8 0
1 0xffff922a93154200 0 3 2.63% 2 2 0
2 0xffff922a93154500 0 4 2.63% 2 2 0
...
Note the new 'Node' column next to the 'Offset'.
=================================================
Shared Cache Line Distribution Pareto
=================================================
#
# ----- HITM ----- -- Store Refs -- Data address
# Num Rmt Lcl L1 Hit L1 Miss Offset Node Pid
# ..... ....... ....... ....... ....... .................. .... .......
#
-------------------------------------------------------------
0 0 8 32 2 0x7f0830100000
-------------------------------------------------------------
0.00% 75.00% 21.88% 0.00% 0x18 0 1791
0.00% 12.50% 37.50% 0.00% 0x18 0 1791
0.00% 0.00% 34.38% 0.00% 0x18 0 1791
Using the mem2node object to get the NUMA node data.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Joe Mario <jmario@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180309101442.9224-8-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Adding mem2node object to allow the easy lookup of the node for the
physical address.
It has following interface:
int mem2node__init(struct mem2node *map, struct perf_env *env);
void mem2node__exit(struct mem2node *map);
int mem2node__node(struct mem2node *map, u64 addr);
The mem2node__toolsinit initialize object from the perf data file
MEM_TOPOLOGY feature data. Following calls to mem2node__node will return
node number for given physical address. The mem2node__exit function
frees the object.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180309101442.9224-3-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Problem and motivation: Once a breakpoint perf event (PERF_TYPE_BREAKPOINT)
is created, there is no flexibility to change the breakpoint type
(bp_type), breakpoint address (bp_addr), or breakpoint length (bp_len). The
only option is to close the perf event and configure a new breakpoint
event. This inflexibility has a significant performance overhead. For
example, sampling-based, lightweight performance profilers (and also
concurrency bug detection tools), monitor different addresses for a short
duration using PERF_TYPE_BREAKPOINT and change the address (bp_addr) to
another address or change the kind of breakpoint (bp_type) from "write" to
a "read" or vice-versa or change the length (bp_len) of the address being
monitored. The cost of these modifications is prohibitive since it involves
unmapping the circular buffer associated with the perf event, closing the
perf event, opening another perf event and mmaping another circular buffer.
Solution: The new ioctl flag for perf events,
PERF_EVENT_IOC_MODIFY_ATTRIBUTES, introduced in this patch takes a pointer
to a struct perf_event_attr as an argument to update an old breakpoint
event with new address, type, and size. This facility allows retaining a
previous mmaped perf events ring buffer and avoids having to close and
reopen another perf event.
This patch supports only changing PERF_TYPE_BREAKPOINT event type; future
implementations can extend this feature. The patch replicates some of its
functionality of modify_user_hw_breakpoint() in
kernel/events/hw_breakpoint.c. modify_user_hw_breakpoint cannot be called
directly since perf_event_ctx_lock() is already held in _perf_ioctl().
Evidence: Experiments show that the baseline (not able to modify an already
created breakpoint) costs an order of magnitude (~10x) more than the
suggested optimization (having the ability to dynamically modifying a
configured breakpoint via ioctl). When the breakpoints typically do not
trap, the speedup due to the suggested optimization is ~10x; even when the
breakpoints always trap, the speedup is ~4x due to the suggested
optimization.
Testing: tests posted at
https://github.com/linux-contrib/perf_event_modify_bp demonstrate the
performance significance of this patch. Tests also check the functional
correctness of the patch.
Signed-off-by: Milind Chabbi <chabbi.milind@gmail.com>
[ Using modify_user_hw_breakpoint_check function. ]
[ Reformated PERF_EVENT_IOC_*, so the values are all in one column. ]
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Hari Bathini <hbathini@linux.vnet.ibm.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Oleg Nesterov <onestero@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Link: http://lkml.kernel.org/r/20180312134548.31532-8-jolsa@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Mark reported his arm64 perf fuzzer runs sometimes splat like:
armv8pmu_read_counter+0x1e8/0x2d8
armpmu_event_update+0x8c/0x188
armpmu_read+0xc/0x18
perf_output_read+0x550/0x11e8
perf_event_read_event+0x1d0/0x248
perf_event_exit_task+0x468/0xbb8
do_exit+0x690/0x1310
do_group_exit+0xd0/0x2b0
get_signal+0x2e8/0x17a8
do_signal+0x144/0x4f8
do_notify_resume+0x148/0x1e8
work_pending+0x8/0x14
which asserts that we only call pmu::read() on ACTIVE events.
The above callchain does:
perf_event_exit_task()
perf_event_exit_task_context()
task_ctx_sched_out() // INACTIVE
perf_event_exit_event()
perf_event_set_state(EXIT) // EXIT
sync_child_event()
perf_event_read_event()
perf_output_read()
perf_output_read_group()
leader->pmu->read()
Which results in doing a pmu::read() on an !ACTIVE event.
I _think_ this is 'new' since we added attr.inherit_stat, which added
the perf_event_read_event() to the exit path, without that
perf_event_read_output() would only trigger from samples and for
@event to trigger a sample, it's leader _must_ be ACTIVE too.
Still, adding this check makes it consistent with the @sub case for
the siblings.
Reported-and-Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
