leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

perf trace: Beautify statx syscall 'flag' and 'mask' arguments

Browse Source 
To test it, build samples/statx/test_statx, which I did as:

  $ make headers_install
  $ cc -I ~/git/linux/usr/include samples/statx/test-statx.c -o /tmp/statx

And then use perf trace on it:

  # perf trace -e statx /tmp/statx /etc/passwd
  statx(/etc/passwd) = 0
  results=7ff
    Size: 3496            Blocks: 8          IO Block: 4096    regular file
  Device: fd:00           Inode: 280156      Links: 1
  Access: (0644/-rw-r--r--)  Uid:     0   Gid:     0
  Access: 2017-03-29 16:01:01.650073438-0300
  Modify: 2017-03-10 16:25:14.156479354-0300
  Change: 2017-03-10 16:25:14.171479328-0300
     0.000 ( 0.007 ms): statx/30648 statx(dfd: CWD, filename: 0x7ef503f4, flags: SYMLINK_NOFOLLOW, mask: TYPE|MODE|NLINK|UID|GID|ATIME|MTIME|CTIME|INO|SIZE|BLOCKS|BTIME, buffer: 0x7fff7ef4eb10) = 0
  #

Using the test-stat.c options to change the mask:

  # perf trace -e statx /tmp/statx -O /etc/passwd > /dev/null
     0.000 ( 0.008 ms): statx/30745 statx(dfd: CWD, filename: 0x3a0753f4, flags: SYMLINK_NOFOLLOW, mask: BTIME, buffer: 0x7ffd3a0735c0) = 0
  #
  # perf trace -e statx /tmp/statx -A /etc/passwd > /dev/null
     0.000 ( 0.010 ms): statx/30757 statx(dfd: CWD, filename: 0xa94e63f4, flags: SYMLINK_NOFOLLOW|NO_AUTOMOUNT, mask: TYPE|MODE|NLINK|UID|GID|ATIME|MTIME|CTIME|INO|SIZE|BLOCKS|BTIME, buffer: 0x7ffea94e49d0) = 0
  #
  # trace --no-inherit -e statx /tmp/statx -F /etc/passwd > /dev/null
     0.000 ( 0.011 ms): statx(dfd: CWD, filename: 0x3b02d3f3, flags: SYMLINK_NOFOLLOW|STATX_FORCE_SYNC, mask: TYPE|MODE|NLINK|UID|GID|ATIME|MTIME|CTIME|INO|SIZE|BLOCKS|BTIME, buffer: 0x7ffd3b02c850) = 0
  #
  # trace --no-inherit -e statx /tmp/statx -F -L /etc/passwd > /dev/null
     0.000 ( 0.008 ms): statx(dfd: CWD, filename: 0x15cff3f3, flags: STATX_FORCE_SYNC, mask: TYPE|MODE|NLINK|UID|GID|ATIME|MTIME|CTIME|INO|SIZE|BLOCKS|BTIME, buffer: 0x7fff15cfdda0) = 0
  #
  # trace --no-inherit -e statx /tmp/statx -D -O /etc/passwd > /dev/null
     0.000 ( 0.009 ms): statx(dfd: CWD, filename: 0xfa37f3f3, flags: SYMLINK_NOFOLLOW|STATX_DONT_SYNC, mask: BTIME, buffer: 0x7ffffa37da20) = 0
  #

Adding a probe to get the filename collected as well:

  # perf probe 'vfs_getname=getname_flags:72 pathname=result->name:string'
  Added new event:
    probe:vfs_getname    (on getname_flags:72 with pathname=result->name:string)

  You can now use it in all perf tools, such as:

	  perf record -e probe:vfs_getname -aR sleep 1

  # trace --no-inherit -e statx /tmp/statx -D -O /etc/passwd > /dev/null
     0.169 ( 0.007 ms): statx(dfd: CWD, filename: /etc/passwd, flags: SYMLINK_NOFOLLOW|STATX_DONT_SYNC, mask: BTIME, buffer: 0x7ffda9bf50f0) = 0
  #

Same technique could be used to collect and beautify the result put in
the 'buffer' argument.

Finally do a system wide 'perf trace' session looking for any use of statx,
then run the test proggie with various flags:

  # trace -e statx
   16612.967 ( 0.028 ms): statx/4562 statx(dfd: CWD, filename: /tmp/statx, flags: SYMLINK_NOFOLLOW, mask: TYPE|MODE|NLINK|UID|GID|ATIME|MTIME|CTIME|INO|SIZE|BLOCKS|BTIME, buffer: 0x7ffef195d660) = 0
   33064.447 ( 0.011 ms): statx/4569 statx(dfd: CWD, filename: /tmp/statx, flags: SYMLINK_NOFOLLOW|STATX_FORCE_SYNC, mask: TYPE|MODE|NLINK|UID|GID|ATIME|MTIME|CTIME|INO|SIZE|BLOCKS|BTIME, buffer: 0x7ffc5484c790) = 0
   36050.891 ( 0.023 ms): statx/4576 statx(dfd: CWD, filename: /tmp/statx, flags: SYMLINK_NOFOLLOW, mask: BTIME, buffer: 0x7ffeb18b66e0) = 0
   38039.889 ( 0.023 ms): statx/4584 statx(dfd: CWD, filename: /tmp/statx, flags: SYMLINK_NOFOLLOW, mask: TYPE|MODE|NLINK|UID|GID|ATIME|MTIME|CTIME|INO|SIZE|BLOCKS|BTIME, buffer: 0x7fff1db0ea90) = 0
  ^C#

This one also starts moving the beautifiers from files directly included
in builtin-trace.c to separate objects + a beauty.h header with
prototypes, so that we can add test cases in tools/perf/tests/ to fire
syscalls with various arguments and then get them intercepted as
syscalls:sys_enter_foo or raw_syscalls:sys_enter + sys_exit to then
format and check that the formatted output is the one we expect.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: David Ahern <dsahern@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-xvzw8eynffvez5czyzidhrno@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Arnaldo Carvalho de Melo 2017-03-14 16:19:30 -03:00
parent 3e00cbe889
commit fd5cead23f
6 changed files with 104 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
tools/perf/Build
View File

@ -50,5 +50,6 @@ libperf-y += util/
libperf-y += arch/
libperf-y += ui/
libperf-y += scripts/
libperf-y += trace/beauty/
gtk-y += ui/gtk/

1
tools/perf/arch/x86/entry/syscalls/syscall_64.tbl
View File

@ -338,6 +338,7 @@
329 common pkey_mprotect sys_pkey_mprotect
330 common pkey_alloc sys_pkey_alloc
331 common pkey_free sys_pkey_free
332 common statx sys_statx
#
# x32-specific system call numbers start at 512 to avoid cache impact

14
tools/perf/builtin-trace.c
View File

@ -31,6 +31,7 @@
#include "util/intlist.h"
#include "util/thread_map.h"
#include "util/stat.h"
#include "trace/beauty/beauty.h"
#include "trace-event.h"
#include "util/parse-events.h"
#include "util/bpf-loader.h"
@ -267,15 +268,6 @@ out_delete:
({ struct syscall_tp *fields = evsel->priv; \
fields->name.pointer(&fields->name, sample); })
struct syscall_arg {
unsigned long val;
struct thread *thread;
struct trace *trace;
void *parm;
u8 idx;
u8 mask;
};
struct strarray {
int offset;
int nr_entries;
@ -771,6 +763,10 @@ static struct syscall_fmt {
.arg_parm = { [0] = &strarray__socket_families, /* family */ }, },
{ .name = "stat", .errmsg = true, .alias = "newstat", },
{ .name = "statfs", .errmsg = true, },
{ .name = "statx", .errmsg = true,
.arg_scnprintf = { [0] = SCA_FDAT, /* flags */
[2] = SCA_STATX_FLAGS, /* flags */
[3] = SCA_STATX_MASK, /* mask */ }, },
{ .name = "swapoff", .errmsg = true,
.arg_scnprintf = { [0] = SCA_FILENAME, /* specialfile */ }, },
{ .name = "swapon", .errmsg = true,

1
tools/perf/trace/beauty/Build Normal file
View File

@ -0,0 +1 @@
libperf-y += statx.o

24
tools/perf/trace/beauty/beauty.h Normal file
View File

@ -0,0 +1,24 @@
#ifndef _PERF_TRACE_BEAUTY_H
#define _PERF_TRACE_BEAUTY_H
#include <linux/types.h>
struct trace;
struct thread;
struct syscall_arg {
unsigned long val;
struct thread *thread;
struct trace *trace;
void *parm;
u8 idx;
u8 mask;
};
size_t syscall_arg__scnprintf_statx_flags(char *bf, size_t size, struct syscall_arg *arg);
#define SCA_STATX_FLAGS syscall_arg__scnprintf_statx_flags
size_t syscall_arg__scnprintf_statx_mask(char *bf, size_t size, struct syscall_arg *arg);
#define SCA_STATX_MASK syscall_arg__scnprintf_statx_mask
#endif /* _PERF_TRACE_BEAUTY_H */

72
tools/perf/trace/beauty/statx.c Normal file
View File

@ -0,0 +1,72 @@
/*
* trace/beauty/statx.c
*
* Copyright (C) 2017, Red Hat Inc, Arnaldo Carvalho de Melo <acme@redhat.com>
*
* Released under the GPL v2. (and only v2, not any later version)
*/
#include "trace/beauty/beauty.h"
#include <linux/kernel.h>
#include <sys/types.h>
#include <uapi/linux/fcntl.h>
#include <uapi/linux/stat.h>
size_t syscall_arg__scnprintf_statx_flags(char *bf, size_t size, struct syscall_arg *arg)
{
int printed = 0, flags = arg->val;
if (flags == 0)
return scnprintf(bf, size, "SYNC_AS_STAT");
#define P_FLAG(n) \
if (flags & AT_##n) { \
printed += scnprintf(bf + printed, size - printed, "%s%s", printed ? "|" : "", #n); \
flags &= ~AT_##n; \
}
P_FLAG(SYMLINK_NOFOLLOW);
P_FLAG(REMOVEDIR);
P_FLAG(SYMLINK_FOLLOW);
P_FLAG(NO_AUTOMOUNT);
P_FLAG(EMPTY_PATH);
P_FLAG(STATX_FORCE_SYNC);
P_FLAG(STATX_DONT_SYNC);
#undef P_FLAG
if (flags)
printed += scnprintf(bf + printed, size - printed, "%s%#x", printed ? "|" : "", flags);
return printed;
}
size_t syscall_arg__scnprintf_statx_mask(char *bf, size_t size, struct syscall_arg *arg)
{
int printed = 0, flags = arg->val;
#define P_FLAG(n) \
if (flags & STATX_##n) { \
printed += scnprintf(bf + printed, size - printed, "%s%s", printed ? "|" : "", #n); \
flags &= ~STATX_##n; \
}
P_FLAG(TYPE);
P_FLAG(MODE);
P_FLAG(NLINK);
P_FLAG(UID);
P_FLAG(GID);
P_FLAG(ATIME);
P_FLAG(MTIME);
P_FLAG(CTIME);
P_FLAG(INO);
P_FLAG(SIZE);
P_FLAG(BLOCKS);
P_FLAG(BTIME);
#undef P_FLAG
if (flags)
printed += scnprintf(bf + printed, size - printed, "%s%#x", printed ? "|" : "", flags);
return printed;
}