The refcount_t type and corresponding API should be used instead of atomic_t
when the variable is used as a reference counter.
This allows to avoid accidental refcounter overflows that might lead to
use-after-free situations.
Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Kook <keescook@chromium.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: David Windsor <dwindsor@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hans Liljestrand <ishkamiel@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kees Kook <keescook@chromium.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matija Glavinic Pecotic <matija.glavinic-pecotic.ext@nokia.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: alsa-devel@alsa-project.org
Link: http://lkml.kernel.org/r/1487691303-31858-3-git-send-email-elena.reshetova@intel.com
[ fixed mixed conversion to refcount in tests/cpumap.c ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The refcount_t type and corresponding API should be used instead of
atomic_t when the variable is used as a reference counter.
This allows to avoid accidental refcounter overflows that might lead to
use-after-free situations.
Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Kook <keescook@chromium.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: alsa-devel@alsa-project.org
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: David Windsor <dwindsor@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hans Liljestrand <ishkamiel@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kees Kook <keescook@chromium.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matija Glavinic Pecotic <matija.glavinic-pecotic.ext@nokia.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1487691303-31858-2-git-send-email-elena.reshetova@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
To aid in catching bugs when using atomics as a reference count.
This is a trimmed down version with just what is used by tools/ at
this point.
After this, the patches submitted by Elena for tools/ doing the
conversion from atomic_ to recount_ methods can be applied and tested.
To activate it, buint perf with:
make DEBUG=1 -C tools/perf
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Elena Reshetova <elena.reshetova@intel.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-dqtxsumns9ov0l9r5x398f19@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Will be included from atomic.h and used in refcount.h
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Elena Reshetova <elena.reshetova@intel.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-pzrydfee75mhq64kazxmf9it@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
When using perf stat on an AMD F15h system with the default hw events
attributes, some of the events don't get counted:
Performance counter stats for 'sleep 1':
0.749208 task-clock (msec) # 0.001 CPUs utilized
1 context-switches # 0.001 M/sec
0 cpu-migrations # 0.000 K/sec
54 page-faults # 0.072 M/sec
1,122,815 cycles # 1.499 GHz
286,740 stalled-cycles-frontend # 25.54% frontend cycles idle
<not counted> stalled-cycles-backend (0.00%)
^^^^^^^^^^^^
<not counted> instructions (0.00%)
^^^^^^^^^^^^
<not counted> branches (0.00%)
<not counted> branch-misses (0.00%)
1.001550070 seconds time elapsed
The reason is that we have the HW watchdog consuming one PMU counter and
when perf tries to schedule 6 events on 6 counters and some of those
counters are constrained to only a specific subset of PMCs by the
hardware, the event scheduling fails.
So issue a hint to disable the HW watchdog around a perf stat session.
Committer note:
Testing it...
# perf stat -d usleep 1
Performance counter stats for 'usleep 1':
1.180203 task-clock (msec) # 0.490 CPUs utilized
1 context-switches # 0.847 K/sec
0 cpu-migrations # 0.000 K/sec
54 page-faults # 0.046 M/sec
184,754 cycles # 0.157 GHz
714,553 instructions # 3.87 insn per cycle
154,661 branches # 131.046 M/sec
7,247 branch-misses # 4.69% of all branches
219,984 L1-dcache-loads # 186.395 M/sec
17,600 L1-dcache-load-misses # 8.00% of all L1-dcache hits (90.16%)
<not counted> LLC-loads (0.00%)
<not counted> LLC-load-misses (0.00%)
0.002406823 seconds time elapsed
Some events weren't counted. Try disabling the NMI watchdog:
echo 0 > /proc/sys/kernel/nmi_watchdog
perf stat ...
echo 1 > /proc/sys/kernel/nmi_watchdog
#
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Robert Richter <rric@kernel.org>
Cc: Vince Weaver <vince@deater.net>
Link: http://lkml.kernel.org/r/20170211183218.ijnvb5f7ciyuunx4@pd.tnic
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Pull cgroup updates from Tejun Heo:
"Several noteworthy changes.
- Parav's rdma controller is finally merged. It is very straight
forward and can limit the abosolute numbers of common rdma
constructs used by different cgroups.
- kernel/cgroup.c got too chubby and disorganized. Created
kernel/cgroup/ subdirectory and moved all cgroup related files
under kernel/ there and reorganized the core code. This hurts for
backporting patches but was long overdue.
- cgroup v2 process listing reimplemented so that it no longer
depends on allocating a buffer large enough to cache the entire
result to sort and uniq the output. v2 has always mangled the sort
order to ensure that users don't depend on the sorted output, so
this shouldn't surprise anybody. This makes the pid listing
functions use the same iterators that are used internally, which
have to have the same iterating capabilities anyway.
- perf cgroup filtering now works automatically on cgroup v2. This
patch was posted a long time ago but somehow fell through the
cracks.
- misc fixes asnd documentation updates"
* 'for-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (27 commits)
kernfs: fix locking around kernfs_ops->release() callback
cgroup: drop the matching uid requirement on migration for cgroup v2
cgroup, perf_event: make perf_event controller work on cgroup2 hierarchy
cgroup: misc cleanups
cgroup: call subsys->*attach() only for subsystems which are actually affected by migration
cgroup: track migration context in cgroup_mgctx
cgroup: cosmetic update to cgroup_taskset_add()
rdmacg: Fixed uninitialized current resource usage
cgroup: Add missing cgroup-v2 PID controller documentation.
rdmacg: Added documentation for rdmacg
IB/core: added support to use rdma cgroup controller
rdmacg: Added rdma cgroup controller
cgroup: fix a comment typo
cgroup: fix RCU related sparse warnings
cgroup: move namespace code to kernel/cgroup/namespace.c
cgroup: rename functions for consistency
cgroup: move v1 mount functions to kernel/cgroup/cgroup-v1.c
cgroup: separate out cgroup1_kf_syscall_ops
cgroup: refactor mount path and clearly distinguish v1 and v2 paths
cgroup: move cgroup v1 specific code to kernel/cgroup/cgroup-v1.c
...
Fix typos and add the following to the scripts/spelling.txt:
an one||a one
I dropped the "an" before "one or more" in
drivers/net/ethernet/sfc/mcdi_pcol.h.
Link: http://lkml.kernel.org/r/1481573103-11329-6-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix typos and add the following to the scripts/spelling.txt:
an union||a union
Link: http://lkml.kernel.org/r/1481573103-11329-5-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix typos and add the following to the scripts/spelling.txt:
an user||a user
an userspace||a userspace
I also added "userspace" to the list since it is a common word in Linux.
I found some instances for "an userfaultfd", but I did not add it to the
list. I felt it is endless to find words that start with "user" such as
"userland" etc., so must draw a line somewhere.
Link: http://lkml.kernel.org/r/1481573103-11329-4-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull networking updates from David Miller:
"Highlights:
1) Support TX_RING in AF_PACKET TPACKET_V3 mode, from Sowmini
Varadhan.
2) Simplify classifier state on sk_buff in order to shrink it a bit.
From Willem de Bruijn.
3) Introduce SIPHASH and it's usage for secure sequence numbers and
syncookies. From Jason A. Donenfeld.
4) Reduce CPU usage for ICMP replies we are going to limit or
suppress, from Jesper Dangaard Brouer.
5) Introduce Shared Memory Communications socket layer, from Ursula
Braun.
6) Add RACK loss detection and allow it to actually trigger fast
recovery instead of just assisting after other algorithms have
triggered it. From Yuchung Cheng.
7) Add xmit_more and BQL support to mvneta driver, from Simon Guinot.
8) skb_cow_data avoidance in esp4 and esp6, from Steffen Klassert.
9) Export MPLS packet stats via netlink, from Robert Shearman.
10) Significantly improve inet port bind conflict handling, especially
when an application is restarted and changes it's setting of
reuseport. From Josef Bacik.
11) Implement TX batching in vhost_net, from Jason Wang.
12) Extend the dummy device so that VF (virtual function) features,
such as configuration, can be more easily tested. From Phil
Sutter.
13) Avoid two atomic ops per page on x86 in bnx2x driver, from Eric
Dumazet.
14) Add new bpf MAP, implementing a longest prefix match trie. From
Daniel Mack.
15) Packet sample offloading support in mlxsw driver, from Yotam Gigi.
16) Add new aquantia driver, from David VomLehn.
17) Add bpf tracepoints, from Daniel Borkmann.
18) Add support for port mirroring to b53 and bcm_sf2 drivers, from
Florian Fainelli.
19) Remove custom busy polling in many drivers, it is done in the core
networking since 4.5 times. From Eric Dumazet.
20) Support XDP adjust_head in virtio_net, from John Fastabend.
21) Fix several major holes in neighbour entry confirmation, from
Julian Anastasov.
22) Add XDP support to bnxt_en driver, from Michael Chan.
23) VXLAN offloads for enic driver, from Govindarajulu Varadarajan.
24) Add IPVTAP driver (IP-VLAN based tap driver) from Sainath Grandhi.
25) Support GRO in IPSEC protocols, from Steffen Klassert"
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1764 commits)
Revert "ath10k: Search SMBIOS for OEM board file extension"
net: socket: fix recvmmsg not returning error from sock_error
bnxt_en: use eth_hw_addr_random()
bpf: fix unlocking of jited image when module ronx not set
arch: add ARCH_HAS_SET_MEMORY config
net: napi_watchdog() can use napi_schedule_irqoff()
tcp: Revert "tcp: tcp_probe: use spin_lock_bh()"
net/hsr: use eth_hw_addr_random()
net: mvpp2: enable building on 64-bit platforms
net: mvpp2: switch to build_skb() in the RX path
net: mvpp2: simplify MVPP2_PRS_RI_* definitions
net: mvpp2: fix indentation of MVPP2_EXT_GLOBAL_CTRL_DEFAULT
net: mvpp2: remove unused register definitions
net: mvpp2: simplify mvpp2_bm_bufs_add()
net: mvpp2: drop useless fields in mvpp2_bm_pool and related code
net: mvpp2: remove unused 'tx_skb' field of 'struct mvpp2_tx_queue'
net: mvpp2: release reference to txq_cpu[] entry after unmapping
net: mvpp2: handle too large value in mvpp2_rx_time_coal_set()
net: mvpp2: handle too large value handling in mvpp2_rx_pkts_coal_set()
net: mvpp2: remove useless arguments in mvpp2_rx_{pkts, time}_coal_set
...
It should call perf_quiet_option() to suppress messages.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: kernel-team@lge.com
Link: http://lkml.kernel.org/r/20170217081742.17417-7-namhyung@kernel.org
[ Fix merge clash with 483635a9d0 ("perf record: Add -a as default target") ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The -q/--quiet option is to suppress any message. Sometimes users just
want to see the numbers and it can be used for that case.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Suggested-and-Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: kernel-team@lge.com
Link: http://lkml.kernel.org/r/20170217081742.17417-6-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
It now can have negative value to suppress the message entirely. So it
needs to check it being positive.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: kernel-team@lge.com
Link: http://lkml.kernel.org/r/20170217081742.17417-3-namhyung@kernel.org
[ Adjust fuzz on tools/perf/util/pmu.c, add > 0 checks in many other places ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The perf_quiet_option() is to suppress all messages. It's intended to
be called just after parsing options.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: kernel-team@lge.com
Link: http://lkml.kernel.org/r/20170217081742.17417-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Running 'perf record' with no target (-a, -p, -t, etc) will now collect
system wide data.
Commiter notes:
Testing it:
[root@jouet ~]# perf record
^C[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 1.351 MB perf.data (366 samples) ]
#
is equivalent to:
# perf record -a
^C[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 1.411 MB perf.data (978 samples) ]
#
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20170217170018.GA15389@krava
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Boris asked for default -a option in case we monitor only uncore events.
While implementing that I thought it might be actually useful to make it
overall default.
Running 'perf stat' will now collect system wide data.
Committer note:
Testing it:
# perf stat
^C
Performance counter stats for 'system wide':
3571.559178 cpu-clock (msec) # 4.000 CPUs utilized
3,346 context-switches # 0.937 K/sec
277 cpu-migrations # 0.078 K/sec
57,271 page-faults # 0.016 M/sec
4,535,633,835 cycles # 1.270 GHz
6,389,736,516 instructions # 1.41 insn per cycle
1,541,293,875 branches # 431.547 M/sec
14,526,396 branch-misses # 0.94% of all branches
0.892950118 seconds time elapsed
#
Requested-and-Acked-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20170217170034.GB15389@krava
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Currently we allow not to specify value for numeric terms and we set
them to value 1. This was originaly meant just for single bit terms to
allow user to type:
$ perf record -e 'cpu/cpu-cycles,any'
instead of:
$ perf record -e 'cpu/cpu-cycles,any=1'
However it works also for multi bits terms like:
$ perf record -e 'cpu/event/' ls
...
$ perf evlist -v
..., config: 0x1, ...
After discussion with Peter we decided making such term usage to fail,
like:
$ perf record -e 'cpu/event/' ls
event syntax error: 'cpu/event/'
\___ no value assigned for term
...
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1487340058-10496-4-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
We need to add yet another parameter to new_term function in following
patch, so it's better to move first all the current params into template
struct parse_events_term and use it as a single argument.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1487340058-10496-3-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Ingo reported following build failure:
On Sat, Feb 11, 2017 at 12:12:34PM +0100, Ingo Molnar wrote:
>
> So I had this oldish 32-bit 15.10 Ubuntu installation around (fully updated), and
> trying to build perf gave me:
>
> deimos:~/tip/tools/perf> make
> BUILD: Doing 'make -j4' parallel build
> make[3]: *** No rule to make target '/usr/include/x86_64-linux-gnu/sys/types.h', needed by 'fixdep.o'. Stop.
> Makefile:42: recipe for target 'fixdep-in.o' failed
> make[2]: *** [fixdep-in.o] Error 2
> /home/mingo/tip/tools/build/Makefile.include:4: recipe for target 'fixdep' failed
> make[1]: *** [fixdep] Error 2
> Makefile:68: recipe for target 'all' failed
> make: *** [all] Error 2
>
> Now this got a bit better after I did a 'make mrproper' in the kernel tree:
>
> deimos:~/tip/tools/perf> make
> BUILD: Doing 'make -j4' parallel build
> HOSTCC fixdep.o
> /home/mingo/tip/tools/build/fixdep: 1: /home/mingo/tip/tools/build/fixdep: Syntax error: "(" unexpected
> /home/mingo/tip/tools/build/Makefile.build:101: recipe for target 'fixdep.o' failed
> make[3]: *** [fixdep.o] Error 2
> Makefile:42: recipe for target 'fixdep-in.o' failed
> make[2]: *** [fixdep-in.o] Error 2
> /home/mingo/tip/tools/build/Makefile.include:4: recipe for target 'fixdep' failed
> make[1]: *** [fixdep] Error 2
> Makefile:68: recipe for target 'all' failed
> make: *** [all] Error 2
>
> After some digging it turns out that my 'fixdep' binary was 64-bit:
>
> deimos:~/tip/tools/perf> file /home/mingo/tip/tools/build/fixdep
> /home/mingo/tip/tools/build/fixdep: ELF 64-bit LSB executable, x86-64, version 1
> (SYSV), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, for GNU/Linux
> 2.6.32, BuildID[sha1]=d527f736b57b5ba47210fbcb562a3b52867d21c1, not stripped
>
> But it did not get cleaned out by 'make clean'.
>
> Only after I did a 'make clean' in tools/ itself, did it get built properly.
It shows we don't clean up properly the fixdep objects, so adding
special rule for that.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Reported-by: Ingo Molnar <mingo@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1487340058-10496-2-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
There are 2 problems wrt. cpu_topology_map on systems with sparse CPUs:
1. offline/absent CPUs will have their socket_id and core_id set to -1
which triggers:
"socket_id number is too big.You may need to upgrade the perf tool."
2. size of cpu_topology_map (perf_env.cpu[]) is allocated based on
_SC_NPROCESSORS_CONF, but can be indexed with CPU ids going above.
Users of perf_env.cpu[] are using CPU id as index. This can lead
to read beyond what was allocated:
==19991== Invalid read of size 4
==19991== at 0x490CEB: check_cpu_topology (topology.c:69)
==19991== by 0x490CEB: test_session_topology (topology.c:106)
...
For example:
_SC_NPROCESSORS_CONF == 16
available: 2 nodes (0-1)
node 0 cpus: 0 6 8 10 16 22 24 26
node 0 size: 12004 MB
node 0 free: 9470 MB
node 1 cpus: 1 7 9 11 23 25 27
node 1 size: 12093 MB
node 1 free: 9406 MB
node distances:
node 0 1
0: 10 20
1: 20 10
This patch changes HEADER_NRCPUS.nr_cpus_available from _SC_NPROCESSORS_CONF
to max_present_cpu and updates any user of cpu_topology_map to iterate
with nr_cpus_avail.
As a consequence HEADER_CPU_TOPOLOGY core_id and socket_id lists get longer,
but maintain compatibility with pre-patch state - index to cpu_topology_map is
CPU id.
perf test 36 -v
36: Session topology :
--- start ---
test child forked, pid 22211
templ file: /tmp/perf-test-gmdX5i
CPU 0, core 0, socket 0
CPU 1, core 0, socket 1
CPU 6, core 10, socket 0
CPU 7, core 10, socket 1
CPU 8, core 1, socket 0
CPU 9, core 1, socket 1
CPU 10, core 9, socket 0
CPU 11, core 9, socket 1
CPU 16, core 0, socket 0
CPU 22, core 10, socket 0
CPU 23, core 10, socket 1
CPU 24, core 1, socket 0
CPU 25, core 1, socket 1
CPU 26, core 9, socket 0
CPU 27, core 9, socket 1
test child finished with 0
---- end ----
Session topology: Ok
Signed-off-by: Jan Stancek <jstancek@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/d7c05c6445fca74a8442c2c73cfffd349c52c44f.1487146877.git.jstancek@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
When build_cpu_topo() encounters offline/absent CPUs, it fails to find any
sysfs entries and returns failure.
This leads to build_cpu_topology() and write_cpu_topology() failing as
well.
Because HEADER_CPU_TOPOLOGY has not been written, read leaves cpu_topology_map
NULL and we get NULL ptr deref at:
...
cmd_test
__cmd_test
test_and_print
run_test
test_session_topology
check_cpu_topology
36: Session topology :
--- start ---
test child forked, pid 14902
templ file: /tmp/perf-test-4CKocW
failed to write feature HEADER_CPU_TOPOLOGY
perf: Segmentation fault
Obtained 9 stack frames.
./perf(sighandler_dump_stack+0x41) [0x5095f1]
/lib64/libc.so.6(+0x35250) [0x7f4b7c3c9250]
./perf(test_session_topology+0x1db) [0x490ceb]
./perf() [0x475b68]
./perf(cmd_test+0x5b9) [0x4763c9]
./perf() [0x4945a3]
./perf(main+0x69f) [0x427e8f]
/lib64/libc.so.6(__libc_start_main+0xf5) [0x7f4b7c3b5b35]
./perf() [0x427fb9]
test child interrupted
---- end ----
Session topology: FAILED!
This patch makes build_cpu_topology() skip offline/absent CPUs, by checking
their presence against cpu_map built from online CPUs.
Signed-off-by: Jan Stancek <jstancek@redhat.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/a271b770175524f4961d4903af33798358a4a518.1487146877.git.jstancek@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Similar to cpu__max_cpu() (which returns the max possible CPU), returns
the max present CPU.
Signed-off-by: Jan Stancek <jstancek@redhat.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/8ea4601b5cacc49927235b4ebac424bd6eeccb06.1487146877.git.jstancek@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The struct branch_stack->branch_stack.cycles field is a u64 :16
bitfield, and this somehow confuses clang 4.0 when checking the
arguments of a printf format, so cast the :16 to unsigned short to help
it.
Silences this:
util/session.c:935:4: error: format specifies type 'unsigned short' but the argument has type 'u64' (aka 'unsigned long') [-Werror,-Wformat]
e->flags.cycles,
^~~~~~~~~~~~~~~
1 error generated.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.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: http://lkml.kernel.org/n/tip-eo2t4uhlbne105z72tvyzkp1@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The -spec=/path/to/file can be used to change what gcc puts in the cc,
ld, etc command lines, but this is not present in clang, filter it out
at the setup.py file by changing python2's internal variable where it
keeps its initial CFLAGS value.
With this all of perf can be built in at least Fedora 25, fixing this
problem:
GEN /tmp/build/perf/python/perf.so
CC /tmp/build/perf/builtin-buildid-list.o
clang-4.0: error: argument unused during compilation: '-specs=/usr/lib/rpm/redhat/redhat-hardened-cc1' [-Werror,-Wunused-command-line-argument]
clang-4.0: error: argument unused during compilation: '-specs=/usr/lib/rpm/redhat/redhat-hardened-cc1' [-Werror,-Wunused-command-line-argument]
error: command 'clang' failed with exit status 1
Now I need to change all the containers where I have clang to build
perf with it, so that we can check that in other distros (opensuse, debian,
ubuntu, etc) this also works.
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: http://lkml.kernel.org/n/tip-g9lhgr162ao8ao29vvf0hgm1@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Gcc has a -spec option to override what options to pass to cc, etc, and
in some distros this is used, like in fedora, where we end up getting
this passed to gcc that makes clang, that doesn't have this option to
stop the build:
CC /tmp/build/perf/util/scripting-engines/trace-event-python.o
clang-4.0: error: argument unused during compilation: '-specs=/usr/lib/rpm/redhat/redhat-hardened-cc1' [-Werror,-Wunused-command-line-argument]
So filter this out when the compiler used is clang, this way we
can build the python scripting support in tools/perf/.
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: http://lkml.kernel.org/n/tip-2gosxoiouf24pnlknp7w7q4z@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
As pointed out by clang, we were not providing a prototype for a
function before using it:
util/parse-events.y:699:6: error: conflicting types for 'parse_events_error'
void parse_events_error(YYLTYPE *loc, void *data,
^
/tmp/build/perf/util/parse-events-bison.c:2224:7: note: previous implicit declaration is here
yyerror (&yylloc, _data, scanner, YY_("syntax error"));
^
/tmp/build/perf/util/parse-events-bison.c:65:25: note: expanded from macro 'yyerror'
#define yyerror parse_events_error
1 error generated.
One line fix it.
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/20170215130605.GC4020@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The alias->unit field is an array, so to check that it is not set we
should see if it is an empty string, i.e. alias->unit[0], instead of
checking alias->unit != NULL, as this will _always_ evaluate to 'true'.
Pointed out by clang.
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/20170214182435.GD4458@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
In a few cases we were using 'enum map_type' and that triggered this
warning when using clang:
util/session.c:1923:16: error: comparison of constant 2 with expression of type 'enum map_type' is always true
[-Werror,-Wtautological-constant-out-of-range-compare]
for (i = 0; i < MAP__NR_TYPES; ++i) {
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: http://lkml.kernel.org/n/tip-i6uyo6bsopa2dghnx8qo7rri@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
So set it only for other compilers, allowing us to overcome yet another
build failure due to an inexistent clang -W option:
error: unknown warning option '-Wno-override-init'; did you mean '-Wno-override-module'? [-Werror,-Wunknown-warning-option]
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: http://lkml.kernel.org/n/tip-oaa1ici3j8nygp4pzl2oobh3@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
As this is a GNU extension and while harmless in this case, we can do
the same thing in a more clearer way by using a existing thread_map and
cpu_map constructors:
With this we avoid this while compiling with clang:
util/evsel.c:1659:17: error: field 'map' with variable sized type 'struct cpu_map' not at the end of a struct or class is a GNU extension
[-Werror,-Wgnu-variable-sized-type-not-at-end]
struct cpu_map map;
^
util/evsel.c:1667:20: error: field 'map' with variable sized type 'struct thread_map' not at the end of a struct or class is a GNU extension
[-Werror,-Wgnu-variable-sized-type-not-at-end]
struct thread_map map;
^
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: http://lkml.kernel.org/n/tip-207juvrqjiar7uvas2s83v5i@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Genuine problem detected with clang, the warnings are spot on:
util/probe-event.c:2079:7: error: variable 'map' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized]
if (addr) {
^~~~
util/probe-event.c:2094:6: note: uninitialized use occurs here
if (map && !is_kprobe) {
^~~
util/probe-event.c:2079:3: note: remove the 'if' if its condition is always true
if (addr) {
^~~~~~~~~~
util/probe-event.c:2075:8: error: variable 'map' is used uninitialized whenever 'if' condition is true [-Werror,-Wsometimes-uninitialized]
if (kernel_get_symbol_address_by_name(tp->symbol,
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
util/probe-event.c:2094:6: note: uninitialized use occurs here
if (map && !is_kprobe) {
^~~
util/probe-event.c:2075:4: note: remove the 'if' if its condition is always false
if (kernel_get_symbol_address_by_name(tp->symbol,
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
util/probe-event.c:2064:17: note: initialize the variable 'map' to silence this warning
struct map *map;
^
= NULL
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-m3501el55i10hctfbmi2qxzr@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
As this is a GNU extension and while harmless in this case, we can do
the same thing in a more clearer way by using an existing thread_map
constructor.
With this we avoid this while compiling with clang:
util/parse-events.c:2024:21: error: field 'map' with variable sized type 'struct thread_map' not at the end of a struct or class is a GNU extension
[-Werror,-Wgnu-variable-sized-type-not-at-end]
struct thread_map map;
^
1 error generated.
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: http://lkml.kernel.org/n/tip-tqocbplnyyhpst6drgm2u4m3@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
As this is a GNU extension and while harmless in this case, we can do
the same thing in a more clearer way by using an existing thread_map
constructor.
With this we avoid this while compiling with clang:
builtin-record.c:659:21: error: field 'map' with variable sized type 'struct thread_map' not at the end of a struct or class is a GNU extension
[-Werror,-Wgnu-variable-sized-type-not-at-end]
struct thread_map map;
^
1 error generated.
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: http://lkml.kernel.org/n/tip-c9drclo52ezxmwa7qxklin2y@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
End result is the same, its an ABI, so the struct won't change, avoid
using a GNU extension, so that we can catch other cases that may be bugs.
Caught when building with clang:
tests/parse-no-sample-id-all.c:53:20: error: field 'attr' with variable sized type 'struct attr_event' not at the end of a struct or class is a GNU extension
[-Werror,-Wgnu-variable-sized-type-not-at-end]
struct attr_event attr;
^
1 error generated.
Testing it:
# perf test sample_id
24: Parse with no sample_id_all bit set : Ok
#
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: http://lkml.kernel.org/n/tip-e2vs1x771fc208uvxnwcf08b@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
When building with clang we get this error:
bench/numa.c:46:9: error: 'dprintf' macro redefined [-Werror,-Wmacro-redefined]
#define dprintf(x...) do { if (g && g->p.show_details >= 1) printf(x); } while (0)
^
/usr/include/bits/stdio2.h:145:12: note: previous definition is here
# define dprintf(fd, ...) \
^
CC /tmp/build/perf/tests/parse-no-sample-id-all.o
1 error generated.
So, make sure it is undefined before using that name.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
Cc: Jakub Jelen <jjelen@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-f654o2svtrutamvxt7igwz74@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This reverts commit 60758d6668.
Now that libsubcmd makes sure that OPT_UINTEGER options will not
return negative values, we can revert this patch while addressing
the problem it solved:
# perf bench futex hash -t -4
# Running 'futex/hash' benchmark:
Error: switch `t' expects an unsigned numerical value
Usage: perf bench futex hash <options>
-t, --threads <n> Specify amount of threads
# perf bench futex hash -t-4
# Running 'futex/hash' benchmark:
Error: switch `t' expects an unsigned numerical value
Usage: perf bench futex hash <options>
-t, --threads <n> Specify amount of threads
#
IMO it is more reasonable to flat out refuse to process a negative
number than to silently turn it into an absolute value.
This also helps in silencing clang's complaint about asking for an
absolute value of an unsigned integer:
bench/futex-hash.c:133:10: error: taking the absolute value of unsigned type 'unsigned int' has no effect [-Werror,-Wabsolute-value]
nsecs = futexbench_sanitize_numeric(nsecs);
^
bench/futex.h:104:42: note: expanded from macro 'futexbench_sanitize_numeric'
#define futexbench_sanitize_numeric(__n) abs((__n))
^
bench/futex-hash.c:133:10: note: remove the call to 'abs' since unsigned values cannot be negative
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-2kl68v22or31vw643m2exz8x@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
To avoid this when using clang:
warning: optimization level '-O6' is not supported; using '-O3' instead
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: http://lkml.kernel.org/n/tip-kaghp8ddvzdsg03putemcq96@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
As it will always evaluate to 'true', as reported by clang:
util/map.c:390:36: error: address of array 'map->dso->name' will always evaluate to 'true' [-Werror,-Wpointer-bool-conversion]
if (map && map->dso && (map->dso->name || map->dso->long_name)) {
~~~~~~~~~~^~~~ ~~
util/map.c:393:22: error: address of array 'map->dso->name' will always evaluate to 'true' [-Werror,-Wpointer-bool-conversion]
else if (map->dso->name)
~~ ~~~~~~~~~~^~~~
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: http://lkml.kernel.org/n/tip-x8cu007cly40kfp8xnpi9kya@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
It will always evaluate to 'true', as clang warns:
CC /tmp/build/perf/tests/perf-record.o
CC /tmp/build/perf/tests/evsel-roundtrip-name.o
tests/perf-record.c:69:24: error: comparison of array 'argv' equal to a null pointer is always false [-Werror,-Wtautological-pointer-compare]
if (evlist == NULL || argv == NULL) {
^~~~ ~~~~
1 error generated.
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: http://lkml.kernel.org/n/tip-o4977g6p9b3peak9ct6ef48q@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
As it is an array, so will always evaluate to 'true', as reported by
clang:
builtin-sched.c:2070:19: error: address of array 'sym->name' will always evaluate to 'true' [-Werror,-Wpointer-bool-conversion]
if (sym && sym->name) {
~~ ~~~~~^~~~
1 warning generated.
So just ditch all those useless checks.
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: http://lkml.kernel.org/n/tip-ydpm927col06paixb775jjx5@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
When a tool can't open counters due to the kernel.perf_event_paranoit
sysctl setting, we inform how to tweak it to allow the operation to
succeed, in addition to that, suggest setting /etc/sysctl.conf to
make the setting permanent.
Suggested-by: Ingo Molnar <mingo@kernel.org>
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: http://lkml.kernel.org/n/tip-4gwe99k4a6p12d4u8bbyttj2@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Fix below compile error:
CC util/scripting-engines/trace-event-perl.o
In file included from /usr/lib/perl5/5.22.2/i686-linux/CORE/perl.h:5673:0,
from util/scripting-engines/trace-event-perl.c:31:
/usr/lib/perl5/5.22.2/i686-linux/CORE/inline.h: In function 'S__is_utf8_char_slow':
/usr/lib/perl5/5.22.2/i686-linux/CORE/inline.h:270:5: error: nested extern declaration of 'Perl___notused' [-Werror=nested-externs]
dTHX; /* The function called below requires thread context */
^
cc1: all warnings being treated as errors
After digging perl5 repository, I find out that we will meet this
compile error with perl from v5.21.1 to v5.25.4
Signed-off-by: Wang YanQing <udknight@gmail.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/20170212024655.GA15997@udknight
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The "delta-abs" compute method will show most changed entries on top.
So users can easily see how much effect between the data. Note that it
also changes the default of -o option to 1 in order to apply the compute
method. To see original-style (sorted by baseline) use -o 0 option.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20170210161856.18422-1-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The diff.compute config variable is to set the default compute method of
perf diff command (-c option). Possible values 'delta' (default),
'delta-abs', 'ratio' and 'wdiff'.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Taeung Song <treeze.taeung@gmail.com>
Link: http://lkml.kernel.org/r/20170210073614.24584-4-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
