linux.git/tools/perf, branch v4.14-rc2

mm: treewide: remove GFP_TEMPORARY allocation flag

2017-09-14T01:53:16+00:00

GFP_TEMPORARY was introduced by commit e12ba74d8ff3 ("Group short-lived
and reclaimable kernel allocations") along with __GFP_RECLAIMABLE.  It's
primary motivation was to allow users to tell that an allocation is
short lived and so the allocator can try to place such allocations close
together and prevent long term fragmentation.  As much as this sounds
like a reasonable semantic it becomes much less clear when to use the
highlevel GFP_TEMPORARY allocation flag.  How long is temporary? Can the
context holding that memory sleep? Can it take locks? It seems there is
no good answer for those questions.

The current implementation of GFP_TEMPORARY is basically GFP_KERNEL |
__GFP_RECLAIMABLE which in itself is tricky because basically none of
the existing caller provide a way to reclaim the allocated memory.  So
this is rather misleading and hard to evaluate for any benefits.

I have checked some random users and none of them has added the flag
with a specific justification.  I suspect most of them just copied from
other existing users and others just thought it might be a good idea to
use without any measuring.  This suggests that GFP_TEMPORARY just
motivates for cargo cult usage without any reasoning.

I believe that our gfp flags are quite complex already and especially
those with highlevel semantic should be clearly defined to prevent from
confusion and abuse.  Therefore I propose dropping GFP_TEMPORARY and
replace all existing users to simply use GFP_KERNEL.  Please note that
SLAB users with shrinkers will still get __GFP_RECLAIMABLE heuristic and
so they will be placed properly for memory fragmentation prevention.

I can see reasons we might want some gfp flag to reflect shorterm
allocations but I propose starting from a clear semantic definition and
only then add users with proper justification.

This was been brought up before LSF this year by Matthew [1] and it
turned out that GFP_TEMPORARY really doesn't have a clear semantic.  It
seems to be a heuristic without any measured advantage for most (if not
all) its current users.  The follow up discussion has revealed that
opinions on what might be temporary allocation differ a lot between
developers.  So rather than trying to tweak existing users into a
semantic which they haven't expected I propose to simply remove the flag
and start from scratch if we really need a semantic for short term
allocations.

[1] http://lkml.kernel.org/r/20170118054945.GD18349@bombadil.infradead.org

[akpm@linux-foundation.org: fix typo]
[akpm@linux-foundation.org: coding-style fixes]
[sfr@canb.auug.org.au: drm/i915: fix up]
  Link: http://lkml.kernel.org/r/20170816144703.378d4f4d@canb.auug.org.au
Link: http://lkml.kernel.org/r/20170728091904.14627-1-mhocko@kernel.org
Signed-off-by: Michal Hocko 
Signed-off-by: Stephen Rothwell 
Acked-by: Mel Gorman 
Acked-by: Vlastimil Babka 
Cc: Matthew Wilcox 
Cc: Neil Brown 
Cc: "Theodore Ts'o" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge tag 'perf-urgent-for-mingo-4.14-20170912' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent

2017-09-13T07:25:10+00:00

Pull perf/urgent fixes from Arnaldo Carvalho de Melo:

- Fix TUI progress bar when delta from new total from that of the
  previous update is greater than the progress "step" (screen width
  progress bar block))  (Jiri Olsa)

- Make tools/lib/api make DEBUG=1 build use -D_FORTIFY_SOURCE=2 not
  to cripple debuginfo, just like tools/perf/ does (Jiri Olsa)

- Avoid leaking the 'perf.data' file to workloads started from the
  'perf record' command line by using the O_CLOEXEC open flag (Jiri Olsa)

- Fix building when libunwind's 'unwind.h' file is present in the
  include path, clashing with tools/perf/util/unwind.h (Milian Wolff)

- Check per .perfconfig section entry flag, not just per section (Taeung Song)

- Support running perf binaries with a dash in their name, needed to
  run perf as an AppImage (Milian Wolff)

- Wait for the right child by using waitpid() when running workloads
  from 'perf stat', also to fix using perf as an AppImage (Milian Wolff)

Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Ingo Molnar

Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2017-09-12T18:28:13+00:00

Pull perf tooling updates from Ingo Molnar:
 "Perf tooling updates and fixes"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf annotate browser: Help for cycling thru hottest instructions with TAB/shift+TAB
  perf stat: Only auto-merge events that are PMU aliases
  perf test: Add test case for PERF_SAMPLE_PHYS_ADDR
  perf script: Support physical address
  perf mem: Support physical address
  perf sort: Add sort option for physical address
  perf tools: Support new sample type for physical address
  perf vendor events powerpc: Remove duplicate events
  perf intel-pt: Fix syntax in documentation of config option
  perf test powerpc: Fix 'Object code reading' test
  perf trace: Support syscall name globbing
  perf syscalltbl: Support glob matching on syscall names
  perf report: Calculate the average cycles of iterations

perf stat: Wait for the correct child

2017-09-12T15:49:13+00:00

When packaging the perf userland application into an AppImage, the
wait() call in perf stat returned too early. It turned out that some
other child process exited, but not the one perf stat launched:

  $ sudo strace -e fork,execve,clone,wait4 -f ./perf-x86_64.AppImage stat sleep 1
  execve("./perf-git.3a73b7f9-x86_64.AppImage", ["./perf-git.3a73b7f9-x86_64.AppIm"..., "stat", "sleep", "1"], 0x7ffec1bbf050 /* 18 vars */) = 0
  clone(child_stack=NULL, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD, child_tidptr=0x7f6a6e7efe50) = 3912
  strace: Process 3912 attached
  [pid  3912] clone(child_stack=NULL, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD, child_tidptr=0x7f6a6e7efe50) = 3914
  strace: Process 3914 attached
  [pid  3912] +++ exited with 0 +++
  [pid  3911] --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=3912, si_uid=0, si_status=0, si_utime=0, si_stime=0} ---
  [pid  3914] clone(strace: Process 3915 attached
  child_stack=0x7f6a6d9fefb0, flags=CLONE_VM|CLONE_FS|CLONE_FILES|CLONE_SIGHAND|CLONE_THREAD|CLONE_SYSVSEM|CLONE_SETTLS|CLONE_PARENT_SETTID|CLONE_CHILD_CLEARTID, parent_tidptr=0x7f6a6d9ff9d0, tls=0x7f6a6d9ff700, child_tidptr=0x7f6a6d9ff9d0) = 3915
  [pid  3911] execve("/tmp/.mount_perf-g6VYMpl/AppRun", ["./perf-git.3a73b7f9-x86_64.AppIm"..., "stat", "sleep", "1"], 0x14aab70 /* 21 vars */) = 0
  [pid  3911] clone(child_stack=NULL, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD, child_tidptr=0x7f4ae113c4d0) = 3916
  strace: Process 3916 attached
  [pid  3911] wait4(-1, [{WIFEXITED(s) && WEXITSTATUS(s) == 0}], 0, NULL) = 3912
  [pid  3916] execve("/usr/libexec/perf-core/sleep", ["sleep", "1"], 0x27d3650 /* 22 vars */) = -1 ENOENT (No such file or directory)
  [pid  3916] execve("/tmp/./sleep", ["sleep", "1"], 0x27d3650 /* 22 vars */) = -1 ENOENT (No such file or directory)
  [pid  3916] execve("/home/milian/.bin/sleep", ["sleep", "1"], 0x27d3650 /* 22 vars */) = -1 ENOENT (No such file or directory)
  [pid  3916] execve("/usr/lib/icecream/libexec/icecc/bin/sleep", ["sleep", "1"], 0x27d3650 /* 22 vars */) = -1 ENOENT (No such file or directory)
  [pid  3916] execve("/ssd2/milian/projects/compiled/other/bin/sleep", ["sleep", "1"], 0x27d3650 /* 22 vars */) = -1 ENOENT (No such file or directory)
  [pid  3916] execve("/home/milian/.bin/kf5/sleep", ["sleep", "1"], 0x27d3650 /* 22 vars */) = -1 ENOENT (No such file or directory)
  [pid  3916] execve("/ssd2/milian/projects/compiled/kf5/bin/sleep", ["sleep", "1"], 0x27d3650 /* 22 vars */) = -1 ENOENT (No such file or directory)
  [pid  3916] execve("/home/milian/projects/compiled/other/bin/sleep", ["sleep", "1"], 0x27d3650 /* 22 vars */) = -1 ENOENT (No such file or directory)
  [pid  3916] execve("/home/milian/projects/compiled/kf5/bin/sleep", ["sleep", "1"], 0x27d3650 /* 22 vars */) = -1 ENOENT (No such file or directory)
  [pid  3916] execve("/usr/local/sbin/sleep", ["sleep", "1"], 0x27d3650 /* 22 vars */) = -1 ENOENT (No such file or directory)
  [pid  3916] execve("/usr/local/bin/sleep", ["sleep", "1"], 0x27d3650 /* 22 vars */) = -1 ENOENT (No such file or directory)
  [pid  3916] execve("/usr/bin/sleep", ["sleep", "1"], 0x27d3650 /* 22 vars */
   Performance counter stats for 'sleep 1':

       	task-clock
       	context-switches
       	cpu-migrations
       	page-faults
       	cycles
       	instructions
             branches
             branch-misses

         0.000047194 seconds time elapsed

  [pid  3916] --- SIGTERM {si_signo=SIGTERM, si_code=SI_USER, si_pid=3911, si_uid=0} ---
  [pid  3916] +++ killed by SIGTERM +++
  [pid  3911] --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_KILLED, si_pid=3916, si_uid=0, si_status=SIGTERM, si_utime=0, si_stime=0} ---
  [pid  3915] --- SIGPIPE {si_signo=SIGPIPE, si_code=SI_USER, si_pid=3914, si_uid=0} ---
  [pid  3911] +++ exited with 0 +++
  [pid  3915] --- SIGHUP {si_signo=SIGHUP, si_code=SI_USER, si_pid=3914, si_uid=0} ---
  [pid  3915] +++ exited with 0 +++
  +++ exited with 0 +++

This patch uses waitpid instead to ensure the call waits for the
debuggee application launched by 'perf stat'. This fixes 'perf stat'
when launched from an AppImage:

  $ ./perf-x86_64.AppImage stat sleep 1

   Performance counter stats for 'sleep 1':

          0.357235      task-clock (msec)         #    0.000 CPUs utilized
                 1      context-switches          #    0.003 M/sec
                 0      cpu-migrations            #    0.000 K/sec
                50      page-faults               #    0.140 M/sec
           1269602      cycles                    #    3.554 GHz
            654278      instructions              #    0.52  insn per cycle
            129963      branches                  #  363.803 M/sec
              7082      branch-misses             #    5.45% of all branches

       1.000633420 seconds time elapsed

Signed-off-by: Milian Wolff 
Cc: David Ahern 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/20170912152523.4497-1-milian.wolff@kdab.com
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Support running perf binaries with a dash in their name

2017-09-12T15:48:54+00:00

Previously the part behind "perf-" was interpreted as an internal perf
command. If the suffix could not be handled, the execution was stopped.
This makes it impossible to launch perf binaries that got renamed to
have the `perf-` prefix. This is e.g. the case for appimages (e.g.
"perf-x86_64.AppImage"), but would also apply to all other scenarios
where users symlink or rename perf themselves:

Status quo with the broken behavior:

  $ ln -s ./perf ./perf-custom-suffix
  $ ./perf-custom-suffix list
  cannot handle custom-suffix internally$

Also note the missing newline at the end of the error message.

With this patch applied, the above works properly:

  $ ./perf-custom-suffix list

  List of pre-defined events (to be used in -e):
  ...

Signed-off-by: Milian Wolff 
Acked-by: David Ahern 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Yao Jin 
Link: http://lkml.kernel.org/r/20170911111422.31903-1-milian.wolff@kdab.com
Signed-off-by: Arnaldo Carvalho de Melo

perf config: Check not only section->from_system_config but also item's

2017-09-12T15:35:11+00:00

Currently section->from_system_config is being checked multiple times.
item->from_system_config should be checked instead, when iterating thru
the items in a section. Fix it.

Signed-off-by: Taeung Song 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Link: http://lkml.kernel.org/r/1504754325-9724-1-git-send-email-treeze.taeung@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo

perf ui progress: Fix progress update

2017-09-12T15:34:54+00:00

We currently update the 'next' variable only with a single step value.
But it's possible the 'adv' update is bigger than single 'step' value.
This would leave 'next' value under counted and force unnecessary
ui_progress__ops->update calls.

Calculate the amount of steps we need for 'adv' update and increase the
'next' with that amounts of steps.

Signed-off-by: Jiri Olsa 
Cc: David Ahern 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/20170908120510.22515-3-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf ui progress: Make sure we always define step value

2017-09-12T15:34:46+00:00

Unlikely, but we could have ui_progress__init being called with total <
16, which would set the next and step variables to 0. That would force
unnecessary ui_progress__ops->update calls because 'next' would never
raise.

Forcing the next and step values to be always > 0.

Signed-off-by: Jiri Olsa 
Cc: David Ahern 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/20170908120510.22515-2-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Open perf.data with O_CLOEXEC flag

2017-09-12T15:34:23+00:00

Do not carry the perf.data file descriptor into the workload process and
close it when perf executes the workload.

Signed-off-by: Jiri Olsa 
Cc: David Ahern 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/20170908084621.31595-2-jolsa@kernel.org
[ Add definitions for O_CLOEXEC for older systems ]
Signed-off-by: Arnaldo Carvalho de Melo

perf tests: Fix compile when libunwind's unwind.h is available

2017-09-12T15:34:02+00:00

When cross compiling perf and I want to link against a self-compiled
libunwind, I usually make the custom path where the libunwind headers
exist visible by adding the libunwind prefix to the include path when
compiling perf, i.e.:

~~~~~
$ ls $HOME/projects/compiled/other/include/
libunwind-coredump.h  libunwind.h         libunwind-x86_64.h
libunwind-common.h  libunwind-dynamic.h   libunwind-ptrace.h
unwind.h
$ make EXTRA_CFLAGS="-I$HOME/projects/compiled/other/include/
~~~~~~

Note the `unwind.h` header from libunwind which leads to compile
errors when compiling tests/dwarf-unwind.c, since it shadows perf's
util/unwind.h:

~~~~~
tests/dwarf-unwind.c:41:32: error: ‘struct unwind_entry’ declared inside parameter list will not be visible outside of this definition or declaration [-Werror]
 static int unwind_entry(struct unwind_entry *entry, void *arg)
                                ^~~~~~~~~~~~
tests/dwarf-unwind.c: In function ‘unwind_entry’:
tests/dwarf-unwind.c:44:22: error: dereferencing pointer to incomplete type ‘struct unwind_entry’
  char *symbol = entry->sym ? entry->sym->name : NULL;
                      ^~
tests/dwarf-unwind.c: In function ‘unwind_thread’:
tests/dwarf-unwind.c:92:8: error: implicit declaration of function ‘unwind__get_entries’; did you mean ‘unwind_entry’? [-Werror=implicit-function-declaration]
  err = unwind__get_entries(unwind_entry, &cnt, thread,
        ^~~~~~~~~~~~~~~~~~~
        unwind_entry
tests/dwarf-unwind.c:92:8: error: nested extern declaration of ‘unwind__get_entries’ [-Werror=nested-externs]
~~~~~~

Fix this compile error by specificing an explicit include of perf's
unwind.h in the util folder.

Signed-off-by: Milian Wolff 
Cc: David Ahern 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Yao Jin 
Link: http://lkml.kernel.org/r/20170906150209.12579-1-milian.wolff@kdab.com
Signed-off-by: Arnaldo Carvalho de Melo