The strncpy() function may leave the destination string buffer
unterminated, better use strlcpy() that we have a __weak fallback
implementation for systems without it.
This fixes this warning on an Alpine Linux Edge system with gcc 8.2:
util/header.c: In function 'perf_event__synthesize_event_update_unit':
util/header.c:3586:2: error: 'strncpy' output truncated before terminating nul copying as many bytes from a string as its length [-Werror=stringop-truncation]
strncpy(ev->data, evsel->unit, size);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
util/header.c:3579:16: note: length computed here
size_t size = strlen(evsel->unit);
^~~~~~~~~~~~~~~~~~~
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Fixes: a6e5281780 ("perf tools: Add event_update event unit type")
Link: https://lkml.kernel.org/n/tip-fiikh5nay70bv4zskw2aa858@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The strncpy() function may leave the destination string buffer
unterminated, better use strlcpy() that we have a __weak fallback
implementation for systems without it.
This fixes this warning on an Alpine Linux Edge system with gcc 8.2:
In function 'decompress_kmodule',
inlined from 'dso__decompress_kmodule_fd' at util/dso.c:305:9:
util/dso.c:298:3: error: 'strncpy' destination unchanged after copying no bytes [-Werror=stringop-truncation]
strncpy(pathname, tmpbuf, len);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
CC /tmp/build/perf/util/values.o
CC /tmp/build/perf/util/debug.o
cc1: all warnings being treated as errors
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Fixes: c9a8a6131f ("perf tools: Move the temp file processing into decompress_kmodule")
Link: https://lkml.kernel.org/n/tip-tl2hdxj64tt4k8btbi6a0ugw@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Use conditional variable logic to synchronize between the reading and
processing threads. Currently it's done by having mutex around rotation
code.
Using a POSIX cond variable to sync both threads after queues rotation:
Process thread:
- Detects data
- Switches queues
- Sets rotate variable
- Waits in pthread_cond_wait()
Read thread:
- Detects rotate is set
- Kicks the process thread with a pthread_cond_signal()
After this rotation is safely completed and both threads can continue
with the new queue.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-3rdeg23rv3brvy1pwt3igvyw@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Add a new thread that takes care of the hist creating to alleviate the
main reader thread so it can keep perf mmaps served in time so that we
reduce the possibility of losing events.
The 'perf top' command now spawns 2 extra threads, the data processing
is the following:
1) The main thread reads the data from mmaps and queues them to
ordered events object;
2) The processing threads takes the data from the ordered events
object and create initial histogram;
3) The GUI thread periodically sorts the initial histogram and
presents it.
Passing the data between threads 1 and 2 is done by having 2 ordered
events queues. One is always being stored by thread 1 while the other is
flushed out in thread 2.
Passing the data between threads 2 and 3 stays the same as was initially
for threads 1 and 3.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-hhf4hllgkmle9wl1aly1jli0@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
When looking at PT or brstackinsn traces with 'perf script' it can be
very useful to see the source code. This adds a simple facility to print
them with 'perf script', if the information is available through dwarf
% perf record ...
% perf script -F insn,ip,sym,srccode
...
4004c6 main
5 for (i = 0; i < 10000000; i++)
4004cd main
5 for (i = 0; i < 10000000; i++)
4004c6 main
5 for (i = 0; i < 10000000; i++)
4004cd main
5 for (i = 0; i < 10000000; i++)
4004cd main
5 for (i = 0; i < 10000000; i++)
4004cd main
5 for (i = 0; i < 10000000; i++)
4004cd main
5 for (i = 0; i < 10000000; i++)
4004cd main
5 for (i = 0; i < 10000000; i++)
4004b3 main
6 v++;
% perf record -b ...
% perf script -F insn,ip,sym,srccode,brstackinsn
...
main+22:
0000000000400543 insn: e8 ca ff ff ff # PRED
|18 f1();
f1:
0000000000400512 insn: 55
|10 {
0000000000400513 insn: 48 89 e5
0000000000400516 insn: b8 00 00 00 00
|11 f2();
000000000040051b insn: e8 d6 ff ff ff # PRED
f2:
00000000004004f6 insn: 55
|5 {
00000000004004f7 insn: 48 89 e5
00000000004004fa insn: 8b 05 2c 0b 20 00
|6 c = a / b;
0000000000400500 insn: 8b 0d 2a 0b 20 00
0000000000400506 insn: 99
0000000000400507 insn: f7 f9
0000000000400509 insn: 89 05 29 0b 20 00
000000000040050f insn: 90
|7 }
0000000000400510 insn: 5d
0000000000400511 insn: c3 # PRED
f1+14:
0000000000400520 insn: b8 00 00 00 00
|12 f2();
0000000000400525 insn: e8 cc ff ff ff # PRED
f2:
00000000004004f6 insn: 55
|5 {
00000000004004f7 insn: 48 89 e5
00000000004004fa insn: 8b 05 2c 0b 20 00
|6 c = a / b;
Not supported for callchains currently, would need some layout changes
there.
Committer notes:
Fixed the build on Alpine Linux (3.4 .. 3.8) by addressing this
warning:
In file included from util/srccode.c:19:0:
/usr/include/sys/fcntl.h:1:2: error: #warning redirecting incorrect #include <sys/fcntl.h> to <fcntl.h> [-Werror=cpp]
#warning redirecting incorrect #include <sys/fcntl.h> to <fcntl.h>
^~~~~~~
cc1: all warnings being treated as errors
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Tested-by: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/20181204001848.24769-1-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Go over the tools/ files that are maintained in Arnaldo's tree and
fix common typos: half of them were in comments, the other half
in JSON files.
No change in functionality intended.
Committer notes:
This was split from a larger patch as there are code that is,
additionally, maintained outside the kernel tree, so to ease
cherry-picking and/or backporting, split this into multiple patches.
Just typos in comments, no need to backport, reducing the possibility of
possible backporting artifacts.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20181203102200.GA104797@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Go over the tools/ files that are maintained in Arnaldo's tree and
fix common typos: half of them were in comments, the other half
in JSON files.
No change in functionality intended.
Committer notes:
This was split from a larger patch as there are code that is,
additionally, maintained outside the kernel tree, so to ease cherry
picking and/or backporting, split this into multiple patches.
This one has information that is presented to the user, albeit in debug
mode.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/20181203102200.GA104797@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
In order to make libtraceevent into a proper library, variables, data
structures and functions require a unique prefix to prevent name space
conflicts.
This renames 'struct tep_event_format' to 'struct tep_event', which
describes more closely the purpose of the struct.
Signed-off-by: Tzvetomir Stoyanov <tstoyanov@vmware.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/20181130154647.436403995@goodmis.org
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
[ Fixup conflict with 6e33c250a88f ("tools lib traceevent: Fix compile warnings in tools/lib/traceevent/event-parse.c") ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Multi AIO trace writing allows caching more kernel data into userspace
memory postponing trace writing for the sake of overall profiling data
thruput increase. It could be seen as kernel data buffer extension into
userspace memory.
With an --aio option value different from 0 (default value is 1) the
tool has capability to cache more and more data into user space along
with delegating spill to AIO.
That allows avoiding to suspend at record__aio_sync() between calls of
record__mmap_read_evlist() and increases profiling data thruput at the
cost of userspace memory.
Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
Reviewed-by: Jiri Olsa <jolsa@redhat.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/050bb053-e7f3-aa83-fde7-f27ff90be7f6@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
When using the -x option, perf stat prints CSV-style output with one
event per line. For each event, it prints the count, the unit, the
event name, the cgroup, and a bunch of other event specific fields (such
as insn per cycles).
When you use CSV-style mode, you expect a normalized output where each
event is printed with the same number of fields regardless of what it is
so it can easily be imported into a spreadsheet or parsed.
For instance, if an event does not have a unit, then print an empty
field for it.
Although this approach was implemented for the unit, it was not for the
cgroup.
When mixing cgroup and non-cgroup events, then non-cgroup events would
not show an empty field, instead the next field was printed, make
columns not line up correctly.
This patch fixes the cgroup output issues by forcing an empty field
for non-cgroup events as soon as one event has cgroup.
Before:
<not counted> @ @cycles @foo @ 0 @100.00@@
2531614 @ @cycles @6420922@100.00@ @
foo cgroup lines up with time_running!
After:
<not counted> @ @cycles @foo @0 @100.00@@
2594834 @ @cycles @ @5287372 @100.00@@
Fields line up.
Signed-off-by: Stephane Eranian <eranian@google.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1541587845-9150-1-git-send-email-eranian@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Commit 0aa802a794 ("perf stat: Get rid of extra clock display
function") introduced scale and unit for clock events. Thus,
perf_stat__update_shadow_stats() now saves scaled values of clock events
in msecs, instead of original nsecs. But while calculating values of
shadow stats we still consider clock event values in nsecs. This results
in a wrong shadow stat values. Ex,
# ./perf stat -e task-clock,cycles ls
<SNIP>
2.60 msec task-clock:u # 0.877 CPUs utilized
2,430,564 cycles:u # 1215282.000 GHz
Fix this by saving original nsec values for clock events in
perf_stat__update_shadow_stats(). After patch:
# ./perf stat -e task-clock,cycles ls
<SNIP>
3.14 msec task-clock:u # 0.839 CPUs utilized
3,094,528 cycles:u # 0.985 GHz
Suggested-by: Jiri Olsa <jolsa@redhat.com>
Reported-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Thomas Richter <tmricht@linux.vnet.ibm.com>
Cc: yuzhoujian@didichuxing.com
Fixes: 0aa802a794 ("perf stat: Get rid of extra clock display function")
Link: http://lkml.kernel.org/r/20181116042843.24067-1-ravi.bangoria@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The weak functions, strcmp_cpuid_str() and get_cpuid_str(), are defined
in pmu.c.
Most of the cpuid related functions, including *_cpuid_str()'s
declaration and platform specific definition, are in header.c/h.
To make the declaration and definition of all cpuid related functions in
a consistent place, move the weak functions to header.c.
There is no functional change.
Suggested-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Link: http://lkml.kernel.org/r/20181121164939.13482-1-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Perf can take minutes to parse an image when -ffunction-section is used.
This is especially true with the kernel image when it is compiled this
way, which is the arm64 default since the patcheset "Enable deadcode
elimination at link time".
Perf organize maps using a rbtree. Whenever perf finds a new symbols, it
first searches this rbtree for the map it belongs to, by strcmp()'aring
section names. When it finds the map with the right name, it uses it to
add the symbol. With a usual image there aren't so many maps but when
using -ffunction-section there's basically one map per function. With
the kernel image that's north of 40,000 maps. For most symbols perf has
to parses the entire rbtree to eventually create a new map and add it.
Consequently perf spends most of the time browsing a rbtree that keeps
getting larger.
This performance fix introduces a secondary rbtree that indexes maps
based on the section name.
Signed-off-by: Eric Saint-Etienne <eric.saint.etienne@oracle.com>
Reviewed-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Reviewed-by: David Aldridge <david.aldridge@oracle.com>
Reviewed-by: Rob Gardner <rob.gardner@oracle.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1542822679-25591-1-git-send-email-eric.saint.etienne@oracle.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The perf tools cannot find the proper event list for the Cascadelake
server. Because the Cascadelake server and the Skylake server have the
same CPU model number, which are used by the perf tools to find the
event list.
The stepping for Skylake server is up to 4.
The stepping for Cascadelake server starts from 5.
The stepping can be used to distinguish between them.
The stepping is added in get_cpuid_str().
The stepping information for Skylake server is updated in mapfile.csv.
A x86 specific strcmp_cpuid_cmp() function is added to handle two CPUID
formats in mapfile.csv, "vendor-family-model-stepping" and
"vendor-family-model":
- If a cpuid-regular-expression from the mapfile.csv using the new
stepping format, a cpuid-string generated on the machine must include
stepping. Otherwise, it is a mismatch.
- If the cpuid-regular-expression using the old non-stepping format,
the stepping in the cpuid-string will be ignored.
The script, using environment string "PERF_CPUID" without stepping on
Skylake server, will be broken. If so, users must fix their scripts.
Committer notes:
Fixed this build error on centos:6 and debian:7:
arch/x86/util/header.c: In function 'is_full_cpuid':
arch/x86/util/header.c:82:39: error: declaration of 'cpuid' shadows a global declaration [-Werror=shadow]
arch/x86/util/header.c:12:1: error: shadowed declaration is here [-Werror=shadow]
arch/x86/util/header.c: In function 'strcmp_cpuid_str':
arch/x86/util/header.c:98:56: error: declaration of 'cpuid' shadows a global declaration [-Werror=shadow]
arch/x86/util/header.c:12:1: error: shadowed declaration is here [-Werror=shadow]
cc1: all warnings being treated as errors
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20181114212416.15665-1-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Depending on which functions are inlined in util/pmu.c, the snprintf()
calls in perf_pmu__parse_{scale,unit,per_pkg,snapshot}() might trigger a
warning:
util/pmu.c: In function 'pmu_aliases':
util/pmu.c:178:31: error: '%s' directive output may be truncated writing up to 255 bytes into a region of size between 0 and 4095 [-Werror=format-truncation=]
snprintf(path, PATH_MAX, "%s/%s.unit", dir, name);
^~
I found this when trying to build perf from Linux 3.16 with gcc 8.
However I can reproduce the problem in mainline if I force
__perf_pmu__new_alias() to be inlined.
Suppress this by using scnprintf() as has been done elsewhere in perf.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20181111184524.fux4taownc6ndbx6@decadent.org.uk
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
When reporting on 'record' server we try to retrieve/use the mnt
namespace of the profiled tasks. We use following API with cookie to
hold the return namespace, roughly:
nsinfo__mountns_enter(struct nsinfo *nsi, struct nscookie *nc)
setns(newns, 0);
...
new ns related open..
...
nsinfo__mountns_exit(struct nscookie *nc)
setns(nc->oldns)
Once finished we setns to old namespace, which also sets the current
working directory (cwd) to "/", trashing the cwd we had.
This is mostly fine, because we use absolute paths almost everywhere,
but it screws up 'perf diff':
# perf diff
failed to open perf.data: No such file or directory (try 'perf record' first)
...
Adding the current working directory to be part of the cookie and
restoring it in the nsinfo__mountns_exit call.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Krister Johansen <kjlx@templeofstupid.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Fixes: 843ff37bb5 ("perf symbols: Find symbols in different mount namespace")
Link: http://lkml.kernel.org/r/20181101170001.30019-1-jolsa@kernel.org
[ No need to check for NULL args for free(), use zfree() for struct members ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Adam reported a record command crash for simple session like:
$ perf record -e cpu-clock ls
with following backtrace:
Program received signal SIGSEGV, Segmentation fault.
3543 ev = event_update_event__new(size + 1, PERF_EVENT_UPDATE__UNIT, evsel->id[0]);
(gdb) bt
#0 perf_event__synthesize_event_update_unit
#1 0x000000000051e469 in perf_event__synthesize_extra_attr
#2 0x00000000004445cb in record__synthesize
#3 0x0000000000444bc5 in __cmd_record
...
We synthesize an update event that needs to touch the evsel id array,
which is not defined at that time. Fix this by forcing the id allocation
for events with their unit defined.
Reflecting possible read_format ID bit in the attr tests.
Reported-by: Yongxin Liu <yongxin.liu@outlook.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adam Lee <leeadamrobert@gmail.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=201477
Fixes: bfd8f72c27 ("perf record: Synthesize unit/scale/... in event update")
Link: http://lkml.kernel.org/r/20181112130012.5424-1-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Pull perf/urgent improvements and fixes from Arnaldo Carvalho de Melo:
Intel PT SQL viewer: (Adrian Hunter)
- Fall back to /usr/local/lib/libxed.so
- Add Selected branches report
- Add help window
- Fix table find when table re-ordered
Intel PT debug log (Adrian Hunter)
- Add more event information
- Add MTC and CYC timestamps
perf record: (Andi Kleen)
- Support weak groups, just like with 'perf stat'
perf trace: (Arnaldo Carvalho de Melo)
- Start augmenting raw_syscalls:{sys_enter,sys_exit}: goal is to have a
generic, arch independent eBPF kernel component that is programmed with
syscall table details, what to copy, how many bytes, pid, arg filters from the
userspace via eBPF maps by the 'perf trace' tool that continues to use all its
argument beautifiers, just taking advantage of the extra pointer contents.
JVMTI: (Gustavo Romero)
- Fix undefined symbol scnprintf in libperf-jvmti.so
perf top: (Jin Yao)
- Display the LBR stats in callchain entries
perf stat: (Thomas Richter)
- Handle different PMU names with common prefix
arm64: Will (Deacon)
- Fix arm64 tools build failure wrt smp_load_{acquire,release}.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
On s390 the CPU Measurement Facility for counters now supports
2 PMUs named cpum_cf (CPU Measurement Facility for counters) and
cpum_cf_diag (CPU Measurement Facility for diagnostic counters)
for one and the same CPU.
Running command
[root@s35lp76 perf]# ./perf stat -e tx_c_tend \
-- ~/mytests/cf-tx-events 1
Measuring transactions
TX_C_TABORT_NO_SPECIAL: 0 expected:0
TX_C_TABORT_SPECIAL: 0 expected:0
TX_C_TEND: 1 expected:1
TX_NC_TABORT: 11 expected:11
TX_NC_TEND: 1 expected:1
Performance counter stats for '/root/mytests/cf-tx-events 1':
2 tx_c_tend
0.002120091 seconds time elapsed
0.000121000 seconds user
0.002127000 seconds sys
[root@s35lp76 perf]#
displays output which is unexpected (and wrong):
2 tx_c_tend
The test program definitely triggers only one transaction, as shown
in line 'TX_C_TEND: 1 expected:1'.
This is caused by the following call sequence:
pmu_lookup() scans and installs a PMU.
+--> pmu_aliases() parses all aliases in directory
.../<pmu-name>/events/* which are file names.
+--> pmu_aliases_parse() Read each file in directory and create
an new alias entry. This is done with
+--> perf_pmu__new_alias() and
+--> __perf_pmu__new_alias() which also check for
identical alias names.
After pmu_aliases() returns, a complete list of event names
for this pmu has been created. Now function
pmu_add_cpu_aliases() is called to add the events listed in the json
| files to the alias list of the cpu.
+--> perf_pmu__find_map() Returns a pointer to the json events.
Now function pmu_add_cpu_aliases() scans through all events listed
in the JSON files for this CPU.
Each json event pmu name is compared with the current PMU being
built up and if they mismatch, the json event is added to the
current PMUs alias list.
To avoid duplicate entries the following comparison is done:
if (!is_arm_pmu_core(name)) {
pname = pe->pmu ? pe->pmu : "cpu";
if (strncmp(pname, name, strlen(pname)))
continue;
}
The culprit is the strncmp() function.
Using current s390 PMU naming, the first PMU is 'cpum_cf'
and a long list of events is added, among them 'tx_c_tend'
When the second PMU named 'cpum_cf_diag' is added, only one event
named 'CF_DIAG' is added by the pmu_aliases() function.
Now function pmu_add_cpu_aliases() is invoked for PMU 'cpum_cf_diag'.
Since the CPUID string is the same for both PMUs, json file events
for PMU named 'cpum_cf' are added to the PMU 'cpm_cf_diag'
This happens because the strncmp() actually compares:
strncmp("cpum_cf", "cpum_cf_diag", 6);
The first parameter is the pmu name taken from the event in
the json file. The second parameter is the pmu name of the PMU
currently being built.
They are different, but the length of the compare only tests the
common prefix and this returns 0(true) when it should return false.
Now all events for PMU cpum_cf are added to the alias list for pmu
cpum_cf_diag.
Later on in function parse_events_add_pmu() the event 'tx_c_end' is
searched in all available PMUs and found twice, adding it two
times to the evsel_list global variable which is the root
of all events. This results in a counter value of 2 instead
of 1.
Output with this patch:
[root@s35lp76 perf]# ./perf stat -e tx_c_tend \
-- ~/mytests/cf-tx-events 1
Measuring transactions
TX_C_TABORT_NO_SPECIAL: 0 expected:0
TX_C_TABORT_SPECIAL: 0 expected:0
TX_C_TEND: 1 expected:1
TX_NC_TABORT: 11 expected:11
TX_NC_TEND: 1 expected:1
Performance counter stats for '/root/mytests/cf-tx-events 1':
1 tx_c_tend
0.001815365 seconds time elapsed
0.000123000 seconds user
0.001756000 seconds sys
[root@s35lp76 perf]#
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Reviewed-by: Sebastien Boisvert <sboisvert@gydle.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: stable@vger.kernel.org
Fixes: 292c34c102 ("perf pmu: Fix core PMU alias list for X86 platform")
Link: http://lkml.kernel.org/r/20181023151616.78193-1-tmricht@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Pull perf updates and fixes from Ingo Molnar:
"These are almost all tooling updates: 'perf top', 'perf trace' and
'perf script' fixes and updates, an UAPI header sync with the merge
window versions, license marker updates, much improved Sparc support
from David Miller, and a number of fixes"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (66 commits)
perf intel-pt/bts: Calculate cpumode for synthesized samples
perf intel-pt: Insert callchain context into synthesized callchains
perf tools: Don't clone maps from parent when synthesizing forks
perf top: Start display thread earlier
tools headers uapi: Update linux/if_link.h header copy
tools headers uapi: Update linux/netlink.h header copy
tools headers: Sync the various kvm.h header copies
tools include uapi: Update linux/mmap.h copy
perf trace beauty: Use the mmap flags table generated from headers
perf beauty: Wire up the mmap flags table generator to the Makefile
perf beauty: Add a generator for MAP_ mmap's flag constants
tools include uapi: Update asound.h copy
tools arch uapi: Update asm-generic/unistd.h and arm64 unistd.h copies
tools include uapi: Update linux/fs.h copy
perf callchain: Honour the ordering of PERF_CONTEXT_{USER,KERNEL,etc}
perf cs-etm: Correct CPU mode for samples
perf unwind: Take pgoff into account when reporting elf to libdwfl
perf top: Do not use overwrite mode by default
perf top: Allow disabling the overwrite mode
perf trace: Beautify mount's first pathname arg
...
