Which is the case in S/390, where symbols were not being resolved
because machine__get_kernel_start was only setting machine->kernel_start
when the just successfully loaded kernel symtab had its map->start set
to !0, when it was left at (1ULL << 63) assuming a partitioning of the
address space for user/kernel, which is not the case in S/390 nor in
Sparc.
So just check if map__load() was successfull and set
machine->kernel_start to zero, fixing kernel symbol resolution on S/390.
Test performed by Thomas:
----
I like this patch. I have done a new build and removed all my debug output to start
from scratch. Without your patch I get this:
# Samples: 4 of event 'cpu-clock'
# Event count (approx.): 1000000
#
# Children Self Command Shared Object Symbol
# ........ ........ ....... ................ ........................
75.00% 0.00% true [unknown] [k] 0x00000000004bedda
|
---0x4bedda
|
|--50.00%--0x42693a
| |
| --25.00%--0x2a72e0
| 0x2af0ca
| 0x3d1003fe4c0
|
--25.00%--0x4272bc
0x26fa84
and with your patch (I just rebuilt the perf tool, nothing else and used the same
perf.data file as input):
# Samples: 4 of event 'cpu-clock'
# Event count (approx.): 1000000
#
# Children Self Command Shared Object Symbol
# ........ ........ ....... .......................... ..................................
75.00% 0.00% true [kernel.vmlinux] [k] pgm_check_handler
|
---pgm_check_handler
do_dat_exception
handle_mm_fault
__handle_mm_fault
filemap_map_pages
|
|--25.00%--rcu_read_lock_held
| rcu_lockdep_current_cpu_online
| 0x3d1003ff4c0
|
--25.00%--lock_release
Looks good to me....
----
Reported-and-Tested-by: Thomas-Mich Richter <tmricht@linux.vnet.ibm.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: Zvonko Kosic <zvonko.kosic@de.ibm.com>
Link: http://lkml.kernel.org/n/tip-dk0n1uzmbe0tbthrpfqlx6bz@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
When no event is specified perf will use the "cycles" hardware event with the highest precision available in the processor, and excluding kernel events for non-root users, so make that clear in the event name by setting the "u" event modifier, i.e. "cycles:upp". E.g.: The default for root: # perf record usleep 1 # perf evlist -v cycles:ppp: ..., precise_ip: 3, exclude_kernel: 0, ... # And for !root: $ perf record usleep 1 $ perf evlist -v cycles:uppp: ... , precise_ip: 3, exclude_kernel: 1, ... $ 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-lf29zcdl422i9knrgde0uwy3@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
To allow probing the max attr.precise_ip setting for non-root users
we unconditionally set attr.exclude_kernel, which makes the detection
work but should be done only for !root, fix it.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Fixes: 97365e81366f ("perf evsel: Set attr.exclude_kernel when probing max attr.precise_ip")
Link: http://lkml.kernel.org/n/tip-bl6bbxzxloonzvm4nvt7oqgj@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Pull perf/urgent fixes from Arnaldo Carvalho de Melo: User visible changes: - Fix max attr.precise_ip probing to make perf use the best cycles:p available in the processor for non root users (Arnaldo Carvalho de Melo) - Fix processing of MMAP events for 32-bit binaries on 64-bit systems when unwind support is not fully integrated, fixing DSO and symbol resolution (Jiri Olsa) Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
We currently fail the MMAP event processing if we don't have the MMAP
event's specific arch unwind support compiled in.
That's wrong and can lead to unresolved mmaps in report output for 32bit
binaries on 64bit server, like in this example on x86_64 server:
$ cat ex.c
int main(int argc, char **argv)
{
while (1) {}
}
$ gcc -o ex -m32 ex.c
$ perf record ./ex
^C[ perf record: Woken up 2 times to write data ]
[ perf record: Captured and wrote 0.371 MB perf.data (9322 samples) ]
Before:
$ perf report --stdio
SNIP
# Overhead Command Shared Object Symbol
# ........ ....... ................ ......................
#
100.00% ex [unknown] [.] 0x00000000080483de
0.00% ex [unknown] [.] 0x00000000f76dba4f
0.00% ex [unknown] [.] 0x00000000f76e4c11
0.00% ex [unknown] [.] 0x00000000f76daa30
After:
$ perf report --stdio
SNIP
# Overhead Command Shared Object Symbol
# ........ ....... ............. ...............
#
100.00% ex ex [.] main
0.00% ex ld-2.24.so [.] _dl_start
0.00% ex ld-2.24.so [.] do_lookup_x
0.00% ex ld-2.24.so [.] _start
The fix is not to fail, just warn if there's not unwind support compiled
in.
Reported-by: Michael Lyle <mlyle@lyle.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20170704131131.27508-1-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
We should set attr.exclude_kernel when probing for attr.precise_ip
level, otherwise !CAP_SYS_ADMIN users will not default to skidless
samples in capable hardware.
The increase in the paranoid level in commit 0161028b7c8a ("perf/core:
Change the default paranoia level to 2") broke this, fix it by excluding
kernel samples when probing.
Before:
$ perf record usleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.018 MB perf.data (6 samples) ]
$ perf evlist -v
cycles:u: sample_freq: 4000, sample_type: IP|TID|TIME|PERIOD, exclude_kernel: 1
After:
$ perf record usleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.018 MB perf.data (8 samples) ]
$ perf evlist -v
cycles:ppp: sample_freq: 4000, sample_type: IP|TID|TIME|PERIOD, exclude_kernel: 1, precise_ip: 3
^^^^^^^^^^^^^
^^^^^^^^^^^^^
^^^^^^^^^^^^^
$
To further clarify: we always set .exclude_kernel when non !CAP_SYS_ADMIN
users profile, its just on the attr.precise_ip probing that we weren't doing
so, fix it.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Fixes: 7f8d1ade1b19 ("perf tools: By default use the most precise "cycles" hw counter available")
Link: http://lkml.kernel.org/n/tip-t2qttwhbnua62o5gt75cueml@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Pull perf updates from Ingo Molnar:
"Most of the changes are for tooling, the main changes in this cycle were:
- Improve Intel-PT hardware tracing support, both on the kernel and
on the tooling side: PTWRITE instruction support, power events for
C-state tracing, etc. (Adrian Hunter)
- Add support to measure SMI cost to the x86 architecture, with
tooling support in 'perf stat' (Kan Liang)
- Support function filtering in 'perf ftrace', plus related
improvements (Namhyung Kim)
- Allow adding and removing fields to the default 'perf script'
columns, using + or - as field prefixes to do so (Andi Kleen)
- Allow resolving the DSO name with 'perf script -F brstack{sym,off},dso'
(Mark Santaniello)
- Add perf tooling unwind support for PowerPC (Paolo Bonzini)
- ... and various other improvements as well"
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (84 commits)
perf auxtrace: Add CPU filter support
perf intel-pt: Do not use TSC packets for calculating CPU cycles to TSC
perf intel-pt: Update documentation to include new ptwrite and power events
perf intel-pt: Add example script for power events and PTWRITE
perf intel-pt: Synthesize new power and "ptwrite" events
perf intel-pt: Move code in intel_pt_synth_events() to simplify attr setting
perf intel-pt: Factor out intel_pt_set_event_name()
perf intel-pt: Tidy messages into called function intel_pt_synth_event()
perf intel-pt: Tidy Intel PT evsel lookup into separate function
perf intel-pt: Join needlessly wrapped lines
perf intel-pt: Remove unused instructions_sample_period
perf intel-pt: Factor out common code synthesizing event samples
perf script: Add synthesized Intel PT power and ptwrite events
perf/x86/intel: Constify the 'lbr_desc[]' array and make a function static
perf script: Add 'synth' field for synthesized event payloads
perf auxtrace: Add itrace option to output power events
perf auxtrace: Add itrace option to output ptwrite events
tools include: Add byte-swapping macros to kernel.h
perf script: Add 'synth' event type for synthesized events
x86/insn: perf tools: Add new ptwrite instruction
...
Decoding auxtrace data can take a long time. To avoid decoding unnecessarily, filter auxtrace data that is collected per-cpu before it is decoded. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Cc: Andi Kleen <ak@linux.intel.com> Link: http://lkml.kernel.org/r/1495786658-18063-38-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
CBR (core-to-bus ratio) packets provide an indication of CPU frequency. A more accurate measure can be made by counting the cycles (given by CYC packets) in between other timing packets (either MTC or TSC). Using TSC packets has at least 2 issues: 1) timing might have stopped (e.g. mwait) or 2) TSC packets within PSB+ might slip past CYC packets. For now, simply do not use TSC packets for calculating CPU cycles to TSC. That leaves the case where 2 MTC packets are used, otherwise falling back to the CBR value. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Cc: Andi Kleen <ak@linux.intel.com> Link: http://lkml.kernel.org/r/1495786658-18063-37-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Synthesize new power and ptwrite events. Power events report changes to C-state but I have also added support for the existing CBR (core-to-bus ratio) packet and included that when outputting power events. The PTWRITE packet is associated with the new "ptwrite" instruction, which is essentially just a way to stuff a 32 or 64 bit value into the PT trace. More details can be found in the patches that add documentation and in the Intel SDM. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Cc: Andi Kleen <ak@linux.intel.com> Link: http://lkml.kernel.org/r/1498811805-2335-1-git-send-email-adrian.hunter@intel.com [ Copy the description of such packet from the patchkit cover message ] Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>