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Jiwei Sun 6d57581659 perf record: Add support for limit perf output file size
The patch adds a new option to limit the output file size, then based on
it, we can create a wrapper of the perf command that uses the option to
avoid exhausting the disk space by the unconscious user.

In order to make the perf.data parsable, we just limit the sample data
size, since the perf.data consists of many headers and sample data and
other data, the actual size of the recorded file will bigger than the
setting value.

Testing it:

  # ./perf record -a -g --max-size=10M
  Couldn't synthesize bpf events.
  [ perf record: perf size limit reached (10249 KB), stopping session ]
  [ perf record: Woken up 32 times to write data ]
  [ perf record: Captured and wrote 10.133 MB perf.data (71964 samples) ]

  # ls -lh perf.data
  -rw------- 1 root root 11M Oct 22 14:32 perf.data

  # ./perf record -a -g --max-size=10K
  [ perf record: perf size limit reached (10 KB), stopping session ]
  Couldn't synthesize bpf events.
  [ perf record: Woken up 0 times to write data ]
  [ perf record: Captured and wrote 1.546 MB perf.data (69 samples) ]

  # ls -l perf.data
  -rw------- 1 root root 1626952 Oct 22 14:36 perf.data

Committer notes:

Fixed the build in multiple distros by using PRIu64 to print u64 struct
members, fixing this:

  builtin-record.c: In function 'record__write':
  builtin-record.c:150:5: error: format '%lu' expects argument of type 'long unsigned int', but argument 3 has type 'u64' [-Werror=format=]
       rec->bytes_written >> 10);
       ^
    CC       /tmp/build/pe

Signed-off-by: Jiwei Sun <jiwei.sun@windriver.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Richard Danter <richard.danter@windriver.com>
Link: http://lore.kernel.org/lkml/20191022080901.3841-1-jiwei.sun@windriver.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-11-07 08:30:19 -03:00
arch perf/x86: Synchronize PMU task contexts on optimized context switches 2019-10-28 12:51:01 +01:00
block blk-rq-qos: fix first node deletion of rq_qos_del() 2019-10-15 10:13:13 -06:00
certs PKCS#7: Refactor verify_pkcs7_signature() 2019-08-05 18:40:18 -04:00
crypto Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2019-09-28 08:14:15 -07:00
Documentation ARM: SoC fixes 2019-10-25 16:00:47 -04:00
drivers Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-10-27 06:55:55 -04:00
fs Seven cifs/smb3 fixes, including three for stable 2019-10-27 06:41:52 -04:00
include perf/core, perf/x86: Introduce swap_task_ctx() method at 'struct pmu' 2019-10-28 12:50:59 +01:00
init Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2019-09-28 08:14:15 -07:00
ipc ipc/sem.c: convert to use built-in RCU list checking 2019-09-25 17:51:41 -07:00
kernel perf/core: Optimize perf_init_event() for TYPE_SOFTWARE 2019-10-28 12:53:28 +01:00
lib lib/vdso: Make clock_getres() POSIX compliant again 2019-10-23 14:48:23 +02:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
mm mm/thp: allow dropping THP from page cache 2019-10-19 06:32:33 -04:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-10-19 17:09:11 -04:00
samples Merge branch 'perf/urgent' into perf/core, to pick up fixes 2019-10-28 12:38:26 +01:00
scripts Modules fixes for v5.4-rc5 2019-10-25 16:11:55 -04:00
security perf_event: Add support for LSM and SELinux checks 2019-10-17 21:31:55 +02:00
sound ALSA: hda: Add Tigerlake/Jasperlake PCI ID 2019-10-23 06:28:50 +02:00
tools perf record: Add support for limit perf output file size 2019-11-07 08:30:19 -03:00
usr kbuild: update compile-test header list for v5.4-rc2 2019-10-05 15:29:49 +09:00
virt KVM/arm fixes for 5.4, take #2 2019-10-22 13:31:29 +02:00
.clang-format clang-format: Update with the latest for_each macro list 2019-08-31 10:00:51 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore Modules updates for v5.4 2019-09-22 10:34:46 -07:00
.mailmap A few MIPS fixes: 2019-10-26 19:43:12 -04:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS MAINTAINERS: Remove Simon as Renesas SoC Co-Maintainer 2019-10-10 08:12:51 -07:00
Kbuild kbuild: do not descend to ./Kbuild when cleaning 2019-08-21 21:03:58 +09:00
Kconfig docs: kbuild: convert docs to ReST and rename to *.rst 2019-06-14 14:21:21 -06:00
MAINTAINERS Merge branch 'perf/urgent' into perf/core, to pick up fixes 2019-10-28 12:38:26 +01:00
Makefile Linux 5.4-rc5 2019-10-27 13:19:19 -04:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.