<feed xmlns='http://www.w3.org/2005/Atom'>
<title>BMC/Intel-BMC/linux.git/tools/perf/builtin-record.c, branch dev-5.2</title>
<subtitle>Intel OpenBMC Linux kernel source tree (mirror)</subtitle>
<id>https://git.radix-linux.su/BMC/Intel-BMC/linux.git/atom?h=dev-5.2</id>
<link rel='self' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/atom?h=dev-5.2'/>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/'/>
<updated>2019-05-15T19:36:49+00:00</updated>
<entry>
<title>perf parse-regs: Split parse_regs</title>
<updated>2019-05-15T19:36:49+00:00</updated>
<author>
<name>Kan Liang</name>
<email>kan.liang@linux.intel.com</email>
</author>
<published>2019-05-14T20:19:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=aeea9062d949584ac1f2f9a20f0e5ed306539a3e'/>
<id>urn:sha1:aeea9062d949584ac1f2f9a20f0e5ed306539a3e</id>
<content type='text'>
The available registers for --int-regs and --user-regs may be different,
e.g. XMM registers.

Split parse_regs into two dedicated functions for --int-regs and
--user-regs respectively.

Modify the warning message. "--user-regs=?" should be applied to show
the available registers for --user-regs.

Signed-off-by: Kan Liang &lt;kan.liang@linux.intel.com&gt;
Tested-by: Ravi Bangoria &lt;ravi.bangoria@linux.ibm.com&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Link: http://lkml.kernel.org/r/1557865174-56264-1-git-send-email-kan.liang@linux.intel.com
[ Changed docs as suggested by Ravi and agreed by Kan ]
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf record: Implement -z,--compression_level[=&lt;n&gt;] option</title>
<updated>2019-05-15T19:36:49+00:00</updated>
<author>
<name>Alexey Budankov</name>
<email>alexey.budankov@linux.intel.com</email>
</author>
<published>2019-03-18T17:44:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=504c1ad11691d1a16e92285bb961728a80c06014'/>
<id>urn:sha1:504c1ad11691d1a16e92285bb961728a80c06014</id>
<content type='text'>
Implemented -z,--compression_level[=&lt;n&gt;] option that enables compression
of mmaped kernel data buffers content in runtime during perf record mode
collection. Default option value is 1 (fastest compression).

Compression overhead has been measured for serial and AIO streaming when
profiling matrix multiplication workload:

      -------------------------------------------------------------
      | SERIAL			  | AIO-1                       |
  ----------------------------------------------------------------|
  |-z | OVH(x) | ratio(x) size(MiB) | OVH(x) | ratio(x) size(MiB) |
  |---------------------------------------------------------------|
  | 0 | 1,00   | 1,000    179,424   | 1,00   | 1,000    187,527   |
  | 1 | 1,04   | 8,427    181,148   | 1,01   | 8,474    188,562   |
  | 2 | 1,07   | 8,055    186,953   | 1,03   | 7,912    191,773   |
  | 3 | 1,04   | 8,283    181,908   | 1,03   | 8,220    191,078   |
  | 5 | 1,09   | 8,101    187,705   | 1,05   | 7,780    190,065   |
  | 8 | 1,05   | 9,217    179,191   | 1,12   | 6,111    193,024   |
  -----------------------------------------------------------------

OVH = (Execution time with -z N) / (Execution time with -z 0)

ratio - compression ratio
size  - number of bytes that was compressed

	size ~= trace size x ratio

Committer notes:

Testing it I noticed that it failed to disable build id processing when
compression is enabled, and as we'd have to uncompress everything to
look for the PERF_RECORD_{MMAP,SAMPLE,etc} to figure out which build ids
to read from DSOs, we better disable build id processing when
compression is enabled, logging with pr_debug() when doing so:

Original patch:

  # perf record -z2
  ^C[ perf record: Woken up 1 times to write data ]
  0x1746e0 [0x76]: failed to process type: 81 [Invalid argument]
  [ perf record: Captured and wrote 1.568 MB perf.data, compressed (original 0.452 MB, ratio is 3.995) ]
  #

After auto-disabling build id processing when compression is enabled:

  $ perf record -z2 sleep 1
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.001 MB perf.data, compressed (original 0.001 MB, ratio is 2.292) ]
  $ perf record -v -z2 sleep 1
  Compression enabled, disabling build id collection at the end of the session.
  &lt;SNIP extra -v pr_debug() messages&gt;
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.001 MB perf.data, compressed (original 0.001 MB, ratio is 2.305) ]
  $

Also, with parts of the patch originally after this one moved to just
before this one we get:

  $ perf record -z2 sleep 1
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.001 MB perf.data, compressed (original 0.001 MB, ratio is 2.371) ]
  $ perf report -D | grep COMPRESS
  0 0x1b8 [0x155]: PERF_RECORD_COMPRESSED: unhandled!
  0 0x30d [0x80]: PERF_RECORD_COMPRESSED: unhandled!
        COMPRESSED events:          2
        COMPRESSED events:          0
  $

I.e. when faced with PERF_RECORD_COMPRESSED that we still have no code
to process, we just show it as not being handled, skip them and
continue, while before we had:

  $ perf report -D | grep COMPRESS
  0x1b8 [0x169]: failed to process type: 81 [Invalid argument]
  Error:
  failed to process sample
  0 0x1b8 [0x169]: PERF_RECORD_COMPRESSED
  $

Signed-off-by: Alexey Budankov &lt;alexey.budankov@linux.intel.com&gt;
Reviewed-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Link: http://lkml.kernel.org/r/9ff06518-ae63-a908-e44d-5d9e56dd66d9@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf record: Implement compression for AIO trace streaming</title>
<updated>2019-05-15T19:36:49+00:00</updated>
<author>
<name>Alexey Budankov</name>
<email>alexey.budankov@linux.intel.com</email>
</author>
<published>2019-03-18T17:44:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=ef781128e47e73f0e5b2ad385cfa685a0719456a'/>
<id>urn:sha1:ef781128e47e73f0e5b2ad385cfa685a0719456a</id>
<content type='text'>
Compression is implemented using the functions from zstd.c. As the memory
to operate on the compression uses mmap-&gt;aio.data[] buffers. If Zstd
streaming compression API fails for some reason the data to be compressed
are just copied into the memory buffers using plain memcpy().

Compressed trace frame consists of an array of PERF_RECORD_COMPRESSED
records. Each element of the array is not longer that PERF_SAMPLE_MAX_SIZE
and consists of perf_event_header followed by the compressed chunk
that is decompressed on the loading stage.

perf_mmap__aio_push() is replaced by perf_mmap__push() which is now used
in the both serial and AIO streaming cases. perf_mmap__push() is extended
with positive return values to signify absence of data ready for
processing.

Signed-off-by: Alexey Budankov &lt;alexey.budankov@linux.intel.com&gt;
Reviewed-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Link: http://lkml.kernel.org/r/77db2b2c-5d03-dbb0-aeac-c4dd92129ab9@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf record: Implement compression for serial trace streaming</title>
<updated>2019-05-15T19:36:49+00:00</updated>
<author>
<name>Alexey Budankov</name>
<email>alexey.budankov@linux.intel.com</email>
</author>
<published>2019-03-18T17:43:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=5d7f41164930ecc1797702b7f9728ac702609ef3'/>
<id>urn:sha1:5d7f41164930ecc1797702b7f9728ac702609ef3</id>
<content type='text'>
Compression is implemented using the functions from zstd.c. As the
memory to operate on the compression uses mmap-&gt;data buffer.

If Zstd streaming compression API fails for some reason the data to be
compressed are just copied into the memory buffers using plain memcpy().

Compressed trace frame consists of an array of PERF_RECORD_COMPRESSED
records. Each element of the array is not longer that
PERF_SAMPLE_MAX_SIZE and consists of perf_event_header followed by the
compressed chunk that is decompressed on the loading stage.

Comitter notes:

Undo some unnecessary line breaks, remove some unnecessary () around
zstd_data to then just get its address, and fix conflicts with
BPF_PROG_INFO/BPF_BTF patchkits.

Signed-off-by: Alexey Budankov &lt;alexey.budankov@linux.intel.com&gt;
Reviewed-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Link: http://lkml.kernel.org/r/744df43f-3932-2594-ddef-1e99a3cad03a@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf mmap: Implement dedicated memory buffer for data compression</title>
<updated>2019-05-15T19:36:49+00:00</updated>
<author>
<name>Alexey Budankov</name>
<email>alexey.budankov@linux.intel.com</email>
</author>
<published>2019-03-18T17:42:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=51255a8af7c41c876c2d715a35ab03c13302a607'/>
<id>urn:sha1:51255a8af7c41c876c2d715a35ab03c13302a607</id>
<content type='text'>
Implemented mmap data buffer that is used as the memory to operate
on when compressing data in case of serial trace streaming.

Signed-off-by: Alexey Budankov &lt;alexey.budankov@linux.intel.com&gt;
Reviewed-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Link: http://lkml.kernel.org/r/49b31321-0f70-392b-9a4f-649d3affe090@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf record: Implement COMPRESSED event record and its attributes</title>
<updated>2019-05-15T19:36:49+00:00</updated>
<author>
<name>Alexey Budankov</name>
<email>alexey.budankov@linux.intel.com</email>
</author>
<published>2019-03-18T17:41:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=42e1fd80a5b8bf9188ddb502b788433ece189aae'/>
<id>urn:sha1:42e1fd80a5b8bf9188ddb502b788433ece189aae</id>
<content type='text'>
Implemented PERF_RECORD_COMPRESSED event, related data types, header
feature and functions to write, read and print feature attributes from
the trace header section.

comp_mmap_len preserves the size of mmaped kernel buffer that was used
during collection. comp_mmap_len size is used on loading stage as the
size of decomp buffer for decompression of COMPRESSED events content.

Committer notes:

Fixed up conflict with BPF_PROG_INFO and BTF_BTF header features.

Signed-off-by: Alexey Budankov &lt;alexey.budankov@linux.intel.com&gt;
Reviewed-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Link: http://lkml.kernel.org/r/ebbaf031-8dda-3864-ebc6-7922d43ee515@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf session: Define 'bytes_transferred' and 'bytes_compressed' metrics</title>
<updated>2019-05-15T19:36:49+00:00</updated>
<author>
<name>Alexey Budankov</name>
<email>alexey.budankov@linux.intel.com</email>
</author>
<published>2019-03-18T17:41:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=d3c8c08e75c4cbb6a940323092b40fcfd1de5380'/>
<id>urn:sha1:d3c8c08e75c4cbb6a940323092b40fcfd1de5380</id>
<content type='text'>
Define 'bytes_transferred' and 'bytes_compressed' metrics to calculate
ratio in the end of the data collection:

	compression ratio = bytes_transferred / bytes_compressed

The 'bytes_transferred' metric accumulates the amount of bytes that was
extracted from the mmaped kernel buffers for compression, while
'bytes_compressed' accumulates the amount of bytes that was received
after applying compression.

Signed-off-by: Alexey Budankov &lt;alexey.budankov@linux.intel.com&gt;
Reviewed-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Link: http://lkml.kernel.org/r/1d4bf499-cb03-26dc-6fc6-f14fec7622ce@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf record: Fix suggestion to get list of registers usable with --user-regs and --intr-regs</title>
<updated>2019-05-15T19:36:46+00:00</updated>
<author>
<name>Arnaldo Carvalho de Melo</name>
<email>acme@redhat.com</email>
</author>
<published>2019-05-13T18:55:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=8e5bc76f2ce39ffd48350d6dd9318d78d07b0bfa'/>
<id>urn:sha1:8e5bc76f2ce39ffd48350d6dd9318d78d07b0bfa</id>
<content type='text'>
  $ perf record -h -I

   Usage: perf record [&lt;options&gt;] [&lt;command&gt;]
      or: perf record [&lt;options&gt;] -- &lt;command&gt; [&lt;options&gt;]

      -I, --intr-regs[=&lt;any register&gt;]
                            sample selected machine registers on interrupt, use -I ? to list register names

  $ m
  $ perf record -I ?
  Workload failed: No such file or directory
  $

  After:

  $ perf record -h -I

   Usage: perf record [&lt;options&gt;] [&lt;command&gt;]
      or: perf record [&lt;options&gt;] -- &lt;command&gt; [&lt;options&gt;]

      -I, --intr-regs[=&lt;any register&gt;]
                            sample selected machine registers on interrupt, use '-I?' to list register names

  $
  $ perf record -I?
  available registers: AX BX CX DX SI DI BP SP IP FLAGS CS SS R8 R9 R10 R11 R12 R13 R14 R15

   Usage: perf record [&lt;options&gt;] [&lt;command&gt;]
      or: perf record [&lt;options&gt;] -- &lt;command&gt; [&lt;options&gt;]

      -I, --intr-regs[=&lt;any register&gt;]
                            sample selected machine registers on interrupt, use '-I?' to list register names
  $

Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Kan Liang &lt;kan.liang@linux.intel.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Stephane Eranian &lt;eranian@google.com&gt;
Fixes: bcc84ec65ad1 ("perf record: Add ability to name registers to record")
Link: https://lkml.kernel.org/n/tip-r0xhfhy5radmkhhcbcfs5izf@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf record: Implement --mmap-flush=&lt;number&gt; option</title>
<updated>2019-04-01T18:18:10+00:00</updated>
<author>
<name>Alexey Budankov</name>
<email>alexey.budankov@linux.intel.com</email>
</author>
<published>2019-03-18T17:40:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=470530bbb8fbbf2a09bd1d7150bb92501c5c54e6'/>
<id>urn:sha1:470530bbb8fbbf2a09bd1d7150bb92501c5c54e6</id>
<content type='text'>
Implement a --mmap-flush option that specifies minimal number of bytes
that is extracted from mmaped kernel buffer to store into a trace. The
default option value is 1 byte what means every time trace writing
thread finds some new data in the mmaped buffer the data is extracted,
possibly compressed and written to a trace.

  $ tools/perf/perf record --mmap-flush 1024 -e cycles -- matrix.gcc
  $ tools/perf/perf record --aio --mmap-flush 1K -e cycles -- matrix.gcc

The option is independent from -z setting, doesn't vary with compression
level and can serve two purposes.

The first purpose is to increase the compression ratio of a trace data.
Larger data chunks are compressed more effectively so the implemented
option allows specifying data chunk size to compress. Also at some cases
executing more write syscalls with smaller data size can take longer
than executing less write syscalls with bigger data size due to syscall
overhead so extracting bigger data chunks specified by the option value
could additionally decrease runtime overhead.

The second purpose is to avoid self monitoring live-lock issue in system
wide (-a) profiling mode. Profiling in system wide mode with compression
(-a -z) can additionally induce data into the kernel buffers along with
the data from monitored processes. If performance data rate and volume
from the monitored processes is high then trace streaming and
compression activity in the tool is also high. High tool process
activity can lead to subtle live-lock effect when compression of single
new byte from some of mmaped kernel buffer leads to generation of the
next single byte at some mmaped buffer. So perf tool process ends up in
endless self monitoring.

Implemented synch parameter is the mean to force data move independently
from the specified flush threshold value. Despite the provided flush
value the tool needs capability to unconditionally drain memory buffers,
at least in the end of the collection.

Committer testing:

Running with the default value, i.e. as soon as there is something to
read go on consuming, we first write the synthesized events, small
chunks of about 128 bytes:

  # perf trace -m 2048 --call-graph dwarf -e write -- perf record
  &lt;SNIP&gt;
     101.142 ( 0.004 ms): perf/25821 write(fd: 3&lt;/root/perf.data&gt;, buf: 0x210db60, count: 120) = 120
                                         __libc_write (/usr/lib64/libpthread-2.28.so)
                                         ion (/home/acme/bin/perf)
                                         record__write (inlined)
                                         process_synthesized_event (/home/acme/bin/perf)
                                         perf_tool__process_synth_event (inlined)
                                         perf_event__synthesize_mmap_events (/home/acme/bin/perf)

Then we move to reading the mmap buffers consuming the events put there
by the kernel perf infrastructure:

     107.561 ( 0.005 ms): perf/25821 write(fd: 3&lt;/root/perf.data&gt;, buf: 0x7f1befc02000, count: 336) = 336
                                         __libc_write (/usr/lib64/libpthread-2.28.so)
                                         ion (/home/acme/bin/perf)
                                         record__write (inlined)
                                         record__pushfn (/home/acme/bin/perf)
                                         perf_mmap__push (/home/acme/bin/perf)
                                         record__mmap_read_evlist (inlined)
                                         record__mmap_read_all (inlined)
                                         __cmd_record (inlined)
                                         cmd_record (/home/acme/bin/perf)
     12919.953 ( 0.136 ms): perf/25821 write(fd: 3&lt;/root/perf.data&gt;, buf: 0x7f1befc83150, count: 184984) = 184984
  &lt;SNIP same backtrace as in the 107.561 timestamp&gt;
     12920.094 ( 0.155 ms): perf/25821 write(fd: 3&lt;/root/perf.data&gt;, buf: 0x7f1befc02150, count: 261816) = 261816
  &lt;SNIP same backtrace as in the 107.561 timestamp&gt;
     12920.253 ( 0.093 ms): perf/25821 write(fd: 3&lt;/root/perf.data&gt;, buf: 0x7f1befb81120, count: 170832) = 170832
  &lt;SNIP same backtrace as in the 107.561 timestamp&gt;

If we limit it to write only when more than 16MB are available for
reading, it throttles that to a quarter of the --mmap-pages set for
'perf record', which by default get to 528384 bytes, found out using
'record -v':

  mmap flush: 132096
  mmap size 528384B

With that in place all the writes coming from
record__mmap_read_evlist(), i.e. from the mmap buffers setup by the
kernel perf infrastructure were at least 132096 bytes long.

Trying with a bigger mmap size:

   perf trace -e write perf record -v -m 2048 --mmap-flush 16M
   74982.928 ( 2.471 ms): perf/26500 write(fd: 3&lt;/root/perf.data&gt;, buf: 0x7ff94a6cc000, count: 3580888) = 3580888
   74985.406 ( 2.353 ms): perf/26500 write(fd: 3&lt;/root/perf.data&gt;, buf: 0x7ff949ecb000, count: 3453256) = 3453256
   74987.764 ( 2.629 ms): perf/26500 write(fd: 3&lt;/root/perf.data&gt;, buf: 0x7ff9496ca000, count: 3859232) = 3859232
   74990.399 ( 2.341 ms): perf/26500 write(fd: 3&lt;/root/perf.data&gt;, buf: 0x7ff948ec9000, count: 3769032) = 3769032
   74992.744 ( 2.064 ms): perf/26500 write(fd: 3&lt;/root/perf.data&gt;, buf: 0x7ff9486c8000, count: 3310520) = 3310520
   74994.814 ( 2.619 ms): perf/26500 write(fd: 3&lt;/root/perf.data&gt;, buf: 0x7ff947ec7000, count: 4194688) = 4194688
   74997.439 ( 2.787 ms): perf/26500 write(fd: 3&lt;/root/perf.data&gt;, buf: 0x7ff9476c6000, count: 4029760) = 4029760

Was again limited to a quarter of the mmap size:

  mmap flush: 2098176
  mmap size 8392704B

A warning about that would be good to have but can be added later,
something like:

  "max flush is a quarter of the mmap size, if wanting to bump the mmap
   flush further, bump the mmap size as well using -m/--mmap-pages"

Also rename the 'sync' parameters to 'synch' to keep tools/perf building
with older glibcs:

  cc1: warnings being treated as errors
  builtin-record.c: In function 'record__mmap_read_evlist':
  builtin-record.c:775: warning: declaration of 'sync' shadows a global declaration
  /usr/include/unistd.h:933: warning: shadowed declaration is here
  builtin-record.c: In function 'record__mmap_read_all':
  builtin-record.c:856: warning: declaration of 'sync' shadows a global declaration
  /usr/include/unistd.h:933: warning: shadowed declaration is here

Signed-off-by: Alexey Budankov &lt;alexey.budankov@linux.intel.com&gt;
Reviewed-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Link: http://lkml.kernel.org/r/f6600d72-ecfa-2eb7-7e51-f6954547d500@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf tools: Save bpf_prog_info and BTF of new BPF programs</title>
<updated>2019-03-21T14:27:04+00:00</updated>
<author>
<name>Song Liu</name>
<email>songliubraving@fb.com</email>
</author>
<published>2019-03-12T05:30:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=d56354dc49091e33d9ffca732ac913ed2df70537'/>
<id>urn:sha1:d56354dc49091e33d9ffca732ac913ed2df70537</id>
<content type='text'>
To fully annotate BPF programs with source code mapping, 4 different
information are needed:

    1) PERF_RECORD_KSYMBOL
    2) PERF_RECORD_BPF_EVENT
    3) bpf_prog_info
    4) btf

This patch handles 3) and 4) for BPF programs loaded after 'perf
record|top'.

For timely process of these information, a dedicated event is added to
the side band evlist.

When PERF_RECORD_BPF_EVENT is received via the side band event, the
polling thread gathers 3) and 4) vis sys_bpf and store them in perf_env.

This information is saved to perf.data at the end of 'perf record'.

Committer testing:

The 'wakeup_watermark' member in 'struct perf_event_attr' is inside a
unnamed union, so can't be used in a struct designated initialization
with older gccs, get it out of that, isolating as 'attr.wakeup_watermark
= 1;' to work with all gcc versions.

We also need to add '--no-bpf-event' to the 'perf record'
perf_event_attr tests in 'perf test', as the way that that test goes is
to intercept the events being setup and looking if they match the fields
described in the control files, since now it finds first the side band
event used to catch the PERF_RECORD_BPF_EVENT, they all fail.

With these issues fixed:

Same scenario as for testing BPF programs loaded before 'perf record' or
'perf top' starts, only start the BPF programs after 'perf record|top',
so that its information get collected by the sideband threads, the rest
works as for the programs loaded before start monitoring.

Add missing 'inline' to the bpf_event__add_sb_event() when
HAVE_LIBBPF_SUPPORT is not defined, fixing the build in systems without
binutils devel files installed.

Signed-off-by: Song Liu &lt;songliubraving@fb.com&gt;
Reviewed-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Cc: Alexei Starovoitov &lt;ast@kernel.org&gt;
Cc: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Stanislav Fomichev &lt;sdf@google.com&gt;
Link: http://lkml.kernel.org/r/20190312053051.2690567-16-songliubraving@fb.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
</feed>
