Arnaldo Carvalho de Melo c4191e55b8 perf trace: Show comm and tid for tracepoint events
So that all events have that info, improving reading by having
information better aligned, etc.

Before:

  # echo 1 > /proc/sys/vm/drop_caches
  # perf trace -e block:*,ext4:*,tools/perf/examples/bpf/augmented_syscalls.c,close cat tools/perf/examples/bpf/hello.c
       0.000 (         ): #include <stdio.h>

  int syscall_enter(openat)(void *args)
  {
  	puts("Hello, world\n");
  	return 0;
  }

  license(GPL);
  cat/2731 openat(dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC)
       0.025 (         ): syscalls:sys_exit_openat:0x3
       0.063 ( 0.022 ms): cat/2731 close(fd: 3) = 0
       0.110 (         ): cat/2731 openat(dfd: CWD, filename: /lib64/libc.so.6, flags: CLOEXEC)
       0.123 (         ): syscalls:sys_exit_openat:0x3
       0.243 ( 0.008 ms): cat/2731 close(fd: 3) = 0
       0.485 (         ): cat/2731 open(filename: /usr/lib/locale/locale-archive, flags: CLOEXEC)
       0.500 (         ): syscalls:sys_exit_open:0x3
       0.531 ( 0.017 ms): cat/2731 close(fd: 3) = 0
       0.587 (         ): cat/2731 openat(dfd: CWD, filename: tools/perf/examples/bpf/hello.c)
       0.601 (         ): syscalls:sys_exit_openat:0x3
       0.631 (         ): ext4:ext4_es_lookup_extent_enter:dev 253,2 ino 1311399 lblk 0
       0.639 (         ): ext4:ext4_es_lookup_extent_exit:dev 253,2 ino 1311399 found 1 [0/1) 5276651 W0x10
       0.654 (         ): block:block_bio_queue:253,2 R 42213208 + 8 [cat]
       0.663 (         ): block:block_bio_remap:8,0 R 58206040 + 8 <- (253,2) 42213208
       0.671 (         ): block:block_bio_remap:8,0 R 175570776 + 8 <- (8,6) 58206040
       0.678 (         ): block:block_bio_queue:8,0 R 175570776 + 8 [cat]
       0.692 (         ): block:block_getrq:8,0 R 175570776 + 8 [cat]
       0.700 (         ): block:block_plug:[cat]
       0.708 (         ): block:block_rq_insert:8,0 R 4096 () 175570776 + 8 [cat]
       0.713 (         ): block:block_unplug:[cat] 1
       0.716 (         ): block:block_rq_issue:8,0 R 4096 () 175570776 + 8 [cat]
       0.949 ( 0.007 ms): cat/2731 close(fd: 3) = 0
       0.969 ( 0.006 ms): cat/2731 close(fd: 1) = 0
       0.982 ( 0.006 ms): cat/2731 close(fd: 2) = 0
  #

After:

  # echo 1 > /proc/sys/vm/drop_caches
  # perf trace -e block:*,ext4:*,tools/perf/examples/bpf/augmented_syscalls.c,close cat tools/perf/examples/bpf/hello.c
       0.000 (         ): cat/1380 openat(dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC)#include <stdio.h>

  int syscall_enter(openat)(void *args)
  {
  	puts("Hello, world\n");
  	return 0;
  }

  license(GPL);

       0.024 (         ): cat/1380 syscalls:sys_exit_openat:0x3
       0.063 ( 0.024 ms): cat/1380 close(fd: 3) = 0
       0.114 (         ): cat/1380 openat(dfd: CWD, filename: /lib64/libc.so.6, flags: CLOEXEC)
       0.127 (         ): cat/1380 syscalls:sys_exit_openat:0x3
       0.247 ( 0.009 ms): cat/1380 close(fd: 3) = 0
       0.484 (         ): cat/1380 open(filename: /usr/lib/locale/locale-archive, flags: CLOEXEC)
       0.499 (         ): cat/1380 syscalls:sys_exit_open:0x3
       0.613 ( 0.010 ms): cat/1380 close(fd: 3) = 0
       0.662 (         ): cat/1380 openat(dfd: CWD, filename: tools/perf/examples/bpf/hello.c)
       0.678 (         ): cat/1380 syscalls:sys_exit_openat:0x3
       0.712 (         ): cat/1380 ext4:ext4_es_lookup_extent_enter:dev 253,2 ino 1311399 lblk 0
       0.721 (         ): cat/1380 ext4:ext4_es_lookup_extent_exit:dev 253,2 ino 1311399 found 1 [0/1) 5276651 W0x10
       0.734 (         ): cat/1380 block:block_bio_queue:253,2 R 42213208 + 8 [cat]
       0.745 (         ): cat/1380 block:block_bio_remap:8,0 R 58206040 + 8 <- (253,2) 42213208
       0.754 (         ): cat/1380 block:block_bio_remap:8,0 R 175570776 + 8 <- (8,6) 58206040
       0.761 (         ): cat/1380 block:block_bio_queue:8,0 R 175570776 + 8 [cat]
       0.780 (         ): cat/1380 block:block_getrq:8,0 R 175570776 + 8 [cat]
       0.791 (         ): cat/1380 block:block_plug:[cat]
       0.802 (         ): cat/1380 block:block_rq_insert:8,0 R 4096 () 175570776 + 8 [cat]
       0.806 (         ): cat/1380 block:block_unplug:[cat] 1
       0.810 (         ): cat/1380 block:block_rq_issue:8,0 R 4096 () 175570776 + 8 [cat]
       1.005 ( 0.011 ms): cat/1380 close(fd: 3) = 0
       1.031 ( 0.008 ms): cat/1380 close(fd: 1) = 0
       1.048 ( 0.008 ms): cat/1380 close(fd: 2) = 0
  #

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-us1mwsupxffs4jlm3uqm5dvj@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2018-08-30 15:52:21 -03:00
2018-08-12 13:41:04 -07:00

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.
See Documentation/00-INDEX for a list of what is contained in each file.

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.
Description
No description provided
Readme 7.8 GiB
Languages
C 97.7%
Assembly 1.6%
Makefile 0.3%
Perl 0.1%