Fixes segmentation fault using, for instance:
(gdb) run record -I -e intel_pt/tsc=1,noretcomp=1/u /bin/ls
Starting program: /home/acme/bin/perf record -I -e intel_pt/tsc=1,noretcomp=1/u /bin/ls
Missing separate debuginfos, use: dnf debuginfo-install glibc-2.22-7.fc23.x86_64
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".
Program received signal SIGSEGV, Segmentation fault.
0 x00000000004b9ea5 in tracepoint_error (e=0x0, err=13, sys=0x19b1370 "sched", name=0x19a5d00 "sched_switch") at util/parse-events.c:410
(gdb) bt
#0 0x00000000004b9ea5 in tracepoint_error (e=0x0, err=13, sys=0x19b1370 "sched", name=0x19a5d00 "sched_switch") at util/parse-events.c:410
#1 0x00000000004b9fc5 in add_tracepoint (list=0x19a5d20, idx=0x7fffffffb8c0, sys_name=0x19b1370 "sched", evt_name=0x19a5d00 "sched_switch", err=0x0, head_config=0x0)
at util/parse-events.c:433
#2 0x00000000004ba334 in add_tracepoint_event (list=0x19a5d20, idx=0x7fffffffb8c0, sys_name=0x19b1370 "sched", evt_name=0x19a5d00 "sched_switch", err=0x0, head_config=0x0)
at util/parse-events.c:498
#3 0x00000000004bb699 in parse_events_add_tracepoint (list=0x19a5d20, idx=0x7fffffffb8c0, sys=0x19b1370 "sched", event=0x19a5d00 "sched_switch", err=0x0, head_config=0x0)
at util/parse-events.c:936
#4 0x00000000004f6eda in parse_events_parse (_data=0x7fffffffb8b0, scanner=0x19a49d0) at util/parse-events.y:391
#5 0x00000000004bc8e5 in parse_events__scanner (str=0x663ff2 "sched:sched_switch", data=0x7fffffffb8b0, start_token=258) at util/parse-events.c:1361
#6 0x00000000004bca57 in parse_events (evlist=0x19a5220, str=0x663ff2 "sched:sched_switch", err=0x0) at util/parse-events.c:1401
#7 0x0000000000518d5f in perf_evlist__can_select_event (evlist=0x19a3b90, str=0x663ff2 "sched:sched_switch") at util/record.c:253
#8 0x0000000000553c42 in intel_pt_track_switches (evlist=0x19a3b90) at arch/x86/util/intel-pt.c:364
#9 0x00000000005549d1 in intel_pt_recording_options (itr=0x19a2c40, evlist=0x19a3b90, opts=0x8edf68 <record+232>) at arch/x86/util/intel-pt.c:664
#10 0x000000000051e076 in auxtrace_record__options (itr=0x19a2c40, evlist=0x19a3b90, opts=0x8edf68 <record+232>) at util/auxtrace.c:539
#11 0x0000000000433368 in cmd_record (argc=1, argv=0x7fffffffde60, prefix=0x0) at builtin-record.c:1264
#12 0x000000000049bec2 in run_builtin (p=0x8fa2a8 <commands+168>, argc=5, argv=0x7fffffffde60) at perf.c:390
#13 0x000000000049c12a in handle_internal_command (argc=5, argv=0x7fffffffde60) at perf.c:451
#14 0x000000000049c278 in run_argv (argcp=0x7fffffffdcbc, argv=0x7fffffffdcb0) at perf.c:495
#15 0x000000000049c60a in main (argc=5, argv=0x7fffffffde60) at perf.c:618
(gdb)
Intel PT attempts to find the sched:sched_switch tracepoint but that seg
faults if tracefs is not readable, because the error reporting structure
is null, as errors are not reported when automatically adding
tracepoints. Fix by checking before using.
Committer note:
This doesn't take place in a kernel that supports
perf_event_attr.context_switch, that is the default way that will be
used for tracking context switches, only in older kernels, like 4.2, in
a machine with Intel PT (e.g. Broadwell) for non-priviledged users.
Further info from a similar patch by Wang:
The error is in tracepoint_error: it assumes the 'e' parameter is valid.
However, there are many situation a parse_event() can be called without
parse_events_error. See result of
$ grep 'parse_events(.*NULL)' ./tools/perf/ -r'
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Tong Zhang <ztong@vt.edu>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: stable@vger.kernel.org # v4.4+
Fixes: 196581717d ("perf tools: Enhance parsing events tracepoint error output")
Link: http://lkml.kernel.org/r/1453809921-24596-2-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Pull timer fixes from Thomas Gleixner:
"The timer departement delivers:
- a regression fix for the NTP code along with a proper selftest
- prevent a spurious timer interrupt in the NOHZ lowres code
- a fix for user space interfaces returning the remaining time on
architectures with CONFIG_TIME_LOW_RES=y
- a few patches to fix COMPILE_TEST fallout"
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
tick/nohz: Set the correct expiry when switching to nohz/lowres mode
clocksource: Fix dependencies for archs w/o HAS_IOMEM
clocksource: Select CLKSRC_MMIO where needed
tick/sched: Hide unused oneshot timer code
kselftests: timers: Add adjtimex SETOFFSET validity tests
ntp: Fix ADJ_SETOFFSET being used w/ ADJ_NANO
itimers: Handle relative timers with CONFIG_TIME_LOW_RES proper
posix-timers: Handle relative timers with CONFIG_TIME_LOW_RES proper
timerfd: Handle relative timers with CONFIG_TIME_LOW_RES proper
hrtimer: Handle remaining time proper for TIME_LOW_RES
clockevents/tcb_clksrc: Prevent disabling an already disabled clock
Pull perf fixes from Thomas Gleixner:
"This is much bigger than typical fixes, but Peter found a category of
races that spurred more fixes and more debugging enhancements. Work
started before the merge window, but got finished only now.
Aside of that this contains the usual small fixes to perf and tools.
Nothing particular exciting"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (43 commits)
perf: Remove/simplify lockdep annotation
perf: Synchronously clean up child events
perf: Untangle 'owner' confusion
perf: Add flags argument to perf_remove_from_context()
perf: Clean up sync_child_event()
perf: Robustify event->owner usage and SMP ordering
perf: Fix STATE_EXIT usage
perf: Update locking order
perf: Remove __free_event()
perf/bpf: Convert perf_event_array to use struct file
perf: Fix NULL deref
perf/x86: De-obfuscate code
perf/x86: Fix uninitialized value usage
perf: Fix race in perf_event_exit_task_context()
perf: Fix orphan hole
perf stat: Do not clean event's private stats
perf hists: Fix HISTC_MEM_DCACHELINE width setting
perf annotate browser: Fix behaviour of Shift-Tab with nothing focussed
perf tests: Remove wrong semicolon in while loop in CQM test
perf: Synchronously free aux pages in case of allocation failure
...
A dma_addr_t is potentially smaller than a phys_addr_t on some archs.
Don't truncate the address when doing the pfn conversion.
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Reported-by: Matthew Wilcox <willy@linux.intel.com>
[willy: fix pfn_t_to_phys as well]
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
$ make -C tools/perf build-test
make[1]: Entering directory `/home/acme/git/linux/tools/perf'
make_pure_O: cd . && make -f Makefile O=/tmp/tmp.mPx0Cmik3f DESTDIR=/tmp/tmp.U0SUmVbtJm
make_clean_all_O: cd . && make -f Makefile O=/tmp/tmp.Yl5UzhTU7T DESTDIR=/tmp/tmp.fop1E4jdER clean all
make_debug_O: cd . && make -f Makefile O=/tmp/tmp.pMn2ozBoXC DESTDIR=/tmp/tmp.azxhDp5sEp DEBUG=1
make_no_libperl_O: cd . && make -f Makefile O=/tmp/tmp.qJPiINMtA7 DESTDIR=/tmp/tmp.KNMrLeGDxZ NO_LIBPERL=1
<SNIP>
More needs to be done to make it more compact, i.e. elide the '-f Makefile',
remove that 'cd . &&', move the DESTDIR= and O= to the end, as they don't
convey that much information besides the fact that they are being set to some
random directory just for this build, move the meat, i.e. the meaningful
feature disabling bits to the start, etc.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-wir3w3o4f1nmbgcxgnx8cj9c@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Powerpc provides hcall events that also provides insights into guest
behaviour. Enhance perf kvm stat to record and analyze hcall events.
- To trace hcall events :
perf kvm stat record
- To show the results :
perf kvm stat report --event=hcall
The result shows the number of hypervisor calls from the guest grouped
by their respective reasons displayed with the frequency.
This patch makes use of two additional tracepoints
"kvm_hv:kvm_hcall_enter" and "kvm_hv:kvm_hcall_exit". To map the hcall
codes to their respective names, it needs a mapping. Such mapping is
added in this patch in book3s_hcalls.h.
# pgrep qemu
A sample output :
19378
60515
2 VMs running.
# perf kvm stat record -a
^C[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 4.153 MB perf.data.guest (39624
samples) ]
# perf kvm stat report -p 60515 --event=hcall
Analyze events for all VMs, all VCPUs:
HCALL-EVENT Samples Samples% Time% MinTime MaxTime AvgTime
H_IPI 822 66.08% 88.10% 0.63us 11.38us 2.05us (+- 1.42%)
H_SEND_CRQ 144 11.58% 3.77% 0.41us 0.88us 0.50us (+- 1.47%)
H_VIO_SIGNAL 118 9.49% 2.86% 0.37us 0.83us 0.47us (+- 1.43%)
H_PUT_TERM_CHAR 76 6.11% 2.07% 0.37us 0.90us 0.52us (+- 2.43%)
H_GET_TERM_CHAR 74 5.95% 2.23% 0.37us 1.70us 0.58us (+- 4.77%)
H_RTAS 6 0.48% 0.85% 1.10us 9.25us 2.70us (+-48.57%)
H_PERFMON 4 0.32% 0.12% 0.41us 0.96us 0.59us (+-20.92%)
Total Samples:1244, Total events handled time:1916.69us.
Signed-off-by: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Alexander Yarygin <yarygin@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Scott Wood <scottwood@freescale.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/1453962787-15376-4-git-send-email-hemant@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf kvm can be used to analyze guest exit reasons. This support already
exists in x86. Hence, porting it to powerpc.
- To trace KVM events :
perf kvm stat record
If many guests are running, we can track for a specific guest by using
--pid as in : perf kvm stat record --pid <pid>
- To see the results :
perf kvm stat report
The result shows the number of exits (from the guest context to
host/hypervisor context) grouped by their respective exit reasons with
their frequency.
Since, different powerpc machines have different KVM tracepoints, this
patch discovers the available tracepoints dynamically and accordingly
looks for them. If any single tracepoint is not present, this support
won't be enabled for reporting. To record, this will fail if any of the
events we are looking to record isn't available. Right now, its only
supported on PowerPC Book3S_HV architectures.
To analyze the different exits, group them and present them (in a slight
descriptive way) to the user, we need a mapping between the "exit code"
(dumped in the kvm_guest_exit tracepoint data) and to its related
Interrupt vector description (exit reason). This patch adds this mapping
in book3s_hv_exits.h.
It records on two available KVM tracepoints for book3s_hv:
"kvm_hv:kvm_guest_exit" and "kvm_hv:kvm_guest_enter".
Here is a sample o/p:
# pgrep qemu
19378
60515
2 Guests are running on the host.
# perf kvm stat record -a
^C[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 4.153 MB perf.data.guest (39624
samples) ]
# perf kvm stat report -p 60515
Analyze events for pid(s) 60515, all VCPUs:
VM-EXIT Samples Samples% Time% MinTime MaxTime Avg time
SYSCALL 9141 63.67% 7.49% 1.26us 5782.39us 9.87us (+- 6.46%)
H_DATA_STORAGE 4114 28.66% 5.07% 1.72us 4597.68us 14.84us (+-20.06%)
HV_DECREMENTER 418 2.91% 4.26% 0.70us 30002.22us 122.58us (+-70.29%)
EXTERNAL 392 2.73% 0.06% 0.64us 104.10us 1.94us (+-18.83%)
RETURN_TO_HOST 287 2.00% 83.11% 1.53us 124240.15us 3486.52us (+-16.81%)
H_INST_STORAGE 5 0.03% 0.00% 1.88us 3.73us 2.39us (+-14.20%)
Total Samples:14357, Total events handled time:1203918.42us.
Signed-off-by: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Alexander Yarygin <yarygin@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Scott Wood <scottwood@freescale.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/1453962787-15376-3-git-send-email-hemant@linux.vnet.ibm.com
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
There is a nasty confusion that, for kernel module, dso->kernel is not
necessary to be DSO_TYPE_KERNEL or DSO_TYPE_GUEST_KERNEL. These two
enums are for vmlinux. See thread [1]. We tried to fix this part but it
is costy.
Code machine__write_buildid_table() is another unfortunate function fall
into this trap that, when issuing buildid event for a kernel module,
cpumode it gives to the event is PERF_RECORD_MISC_USER, not
PERF_RECORD_MISC_KERNEL.
However, even with this bug, most of the time it doesn't causes real
problem. I find this issue when trying to use a perf before commit
3d39ac5386 ("perf machine: No need to have two DSOs lists") to parse a
perf.data generated by newest perf.
[1] https://lkml.org/lkml/2015/9/21/908
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1454089251-203152-1-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The 'tools/perf/test/make' makefile has in its default, 'all' target
builds that will pollute the source code directory, i.e. that will not
use O= variable.
The 'build-test' should be run as often as possible, preferrably after
each non strictly non-code commit, so speed it up by selecting just
the O= targets.
Furthermore it tests both the Makefile.perf file, that is normally
driven by the main Makefile, and the Makefile, reduce the time in half
by having just MK=Makefile, the most usual, tested by 'build-test'.
Please run:
make -C tools/perf -f tests/make
from time to time for testing also the in-place build tests.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-jrt9utscsiqkmjy3ccufostd@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
To prevent the feature check tests to run repeately, one time per
'tests/make' target/test, this patch utilizes the previously introduced
'feature-dump' make target and FEATURES_DUMP variable, making sure that
the feature checkers run only once when doing build-test for normal test
cases.
However, since standard users doesn't reuse features dump result, we'd
better give an option to check their behaviors. The above feature
should be used to make build-test faster only. Only utilize it for
build-test.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1454068269-235999-1-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
I see problem with test-all case speedup, because it does not
comprise checks for 32bits compilations, fix it.
The problem could be noticed by calling:
make -C tools/perf feature-dump
That would end up misdetecting the feature-compile-x32, that, building
using 'gcc -mx32' needs stub headers not present in a fedora 23 devel
machine and thus fail to compile, but ended up appearing as detected,
i.e. present in tools/perf/FEATURE-DUMP as 'feature-compile-x32=1'.
With this fix it correctly appears as 'feature-compile-x32=0' and if we
uninstall the libc devel files for 32 bits (glibc-devel.i686), then the
relevant variable is flipped from 'feature-compile-32=1' to
'feature-compile-32=0'.
The same things happened for bionic and libbabeltrace, that were
misdetected because the are no tested in test-all.c
Reported-and-Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-u0sjaddf1r9m8icpd98ry7fz@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
An i386 binary can be linked correctly even without correct headers.
Which causes problem. For exmaple:
$ mv /tmp/oxygen_root/usr/include/gnu/stubs-32.h{,.bak}
$ make tools/perf
Auto-detecting system features:
... dwarf: [ on ]
[SNIP]
GEN common-cmds.h
CC perf-read-vdso32
In file included from /tmp/oxygen_root/usr/include/features.h:388:0,
from /tmp/oxygen_root/usr/include/stdio.h:27,
from perf-read-vdso.c:1:
/tmp/oxygen_root/usr/include/gnu/stubs.h:7:27: fatal error: gnu/stubs-32.h: No such file or directory
# include <gnu/stubs-32.h>
^
compilation terminated.
...
In this patch we checks not only compiler and linker, but also basic
headers in test-compile test case, make it fail on a platform
lacking correct headers.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Li Zefan <lizefan@huawei.com>
Link: http://lkml.kernel.org/r/1453893742-20603-1-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Libbpf should check the target section before doing relocation to ensure
the relocation is correct. If not, a bug in LLVM causes an error. See
[1]. Also, if an incorrect BPF script uses both global variable and
map, global variable whould be treated as map and be relocated without
error.
This patch saves the id of the map section into obj->efile and compare
target section of a relocation symbol against it during relocation.
Previous patch introduces a test case about this problem. After this
patch:
# ~/perf test BPF
37: Test BPF filter :
37.1: Test basic BPF filtering : Ok
37.2: Test BPF prologue generation : Ok
37.3: Test BPF relocation checker : Ok
# perf test -v BPF
...
37.3: Test BPF relocation checker :
...
libbpf: loading object '[bpf_relocation_test]' from buffer
libbpf: section .strtab, size 126, link 0, flags 0, type=3
libbpf: section .text, size 0, link 0, flags 6, type=1
libbpf: section .data, size 0, link 0, flags 3, type=1
libbpf: section .bss, size 0, link 0, flags 3, type=8
libbpf: section func=sys_write, size 104, link 0, flags 6, type=1
libbpf: found program func=sys_write
libbpf: section .relfunc=sys_write, size 16, link 10, flags 0, type=9
libbpf: section maps, size 16, link 0, flags 3, type=1
libbpf: maps in [bpf_relocation_test]: 16 bytes
libbpf: section license, size 4, link 0, flags 3, type=1
libbpf: license of [bpf_relocation_test] is GPL
libbpf: section version, size 4, link 0, flags 3, type=1
libbpf: kernel version of [bpf_relocation_test] is 40400
libbpf: section .symtab, size 144, link 1, flags 0, type=2
libbpf: map 0 is "my_table"
libbpf: collecting relocating info for: 'func=sys_write'
libbpf: Program 'func=sys_write' contains non-map related relo data pointing to section 65522
bpf: failed to load buffer
Compile BPF program failed.
test child finished with 0
---- end ----
Test BPF filter subtest 2: Ok
[1] https://llvm.org/bugs/show_bug.cgi?id=26243
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1453715801-7732-3-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
There's a bug in LLVM that it can generate unneeded relocation
information. See [1] and [2]. Libbpf should check the target section of
a relocation symbol.
This patch adds a testcase which references a global variable (BPF
doesn't support global variables). Before fixing libbpf, the new test
case can be loaded into kernel, the global variable acts like the first
map. It is incorrect.
Result:
# ~/perf test BPF
37: Test BPF filter :
37.1: Test basic BPF filtering : Ok
37.2: Test BPF prologue generation : Ok
37.3: Test BPF relocation checker : FAILED!
# ~/perf test -v BPF
...
libbpf: loading object '[bpf_relocation_test]' from buffer
libbpf: section .strtab, size 126, link 0, flags 0, type=3
libbpf: section .text, size 0, link 0, flags 6, type=1
libbpf: section .data, size 0, link 0, flags 3, type=1
libbpf: section .bss, size 0, link 0, flags 3, type=8
libbpf: section func=sys_write, size 104, link 0, flags 6, type=1
libbpf: found program func=sys_write
libbpf: section .relfunc=sys_write, size 16, link 10, flags 0, type=9
libbpf: section maps, size 16, link 0, flags 3, type=1
libbpf: maps in [bpf_relocation_test]: 16 bytes
libbpf: section license, size 4, link 0, flags 3, type=1
libbpf: license of [bpf_relocation_test] is GPL
libbpf: section version, size 4, link 0, flags 3, type=1
libbpf: kernel version of [bpf_relocation_test] is 40400
libbpf: section .symtab, size 144, link 1, flags 0, type=2
libbpf: map 0 is "my_table"
libbpf: collecting relocating info for: 'func=sys_write'
libbpf: relocation: insn_idx=7
Success unexpectedly: libbpf error when dealing with relocation
test child finished with -1
---- end ----
Test BPF filter subtest 2: FAILED!
[1] https://llvm.org/bugs/show_bug.cgi?id=26243
[2] https://patchwork.ozlabs.org/patch/571385/
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1453715801-7732-2-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
There are cases where looking at just the next and prev entries is not
enough, like with:
$ readelf -sW /usr/lib/debug/lib/modules/4.3.3-301.fc23.x86_64/vmlinux | grep ffffffff81065ec0
4979: ffffffff81065ec0 53 FUNC LOCAL DEFAULT 1 try_to_free_pud_page
4980: ffffffff81065ec0 53 FUNC LOCAL DEFAULT 1 try_to_free_pte_page
4981: ffffffff81065ec0 53 FUNC LOCAL DEFAULT 1 try_to_free_pmd_page
So just search by name to see if the symbol is in kallsyms.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-jj1vlljg7ol4i713l60rt5ai@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf_event_paranoid was only documented in source code and a perf error
message. Copy the documentation from the error message to
Documentation/sysctl/kernel.txt.
perf_cpu_time_max_percent was already documented but missing from the
list at the top, so add it there.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-doc@vger.kernel.org
Link: http://lkml.kernel.org/r/20160119213515.GG2637@decadent.org.uk
[ Remove reference to external Documentation file, provide info inline, as before ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
