20 Apr, 2017
3 commits
-
There are places where we just need a forward declaration, and others
were we need to include strlist.h and/or strfilter.h, reducing the
impact of changes in headers on the build time, do it.Cc: Adrian Hunter
Cc: David Ahern
Cc: Jiri Olsa
Cc: Namhyung Kim
Cc: Wang Nan
Link: http://lkml.kernel.org/n/tip-zab42gbiki88y9k0csorxekb@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo -
Moving them from util.h, where they don't belong. Since libc already
have string.h, name it slightly differently, as string2.h.Cc: Adrian Hunter
Cc: David Ahern
Cc: Jiri Olsa
Cc: Namhyung Kim
Cc: Wang Nan
Link: http://lkml.kernel.org/n/tip-eh3vz5sqxsrdd8lodoro4jrw@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo -
Needed to use the PRI[xu](32,64) formatting macros.
Cc: Adrian Hunter
Cc: David Ahern
Cc: Jiri Olsa
Cc: Namhyung Kim
Cc: Wang Nan
Link: http://lkml.kernel.org/n/tip-wkbho8kaw24q67dd11q0j39f@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo
28 Feb, 2017
1 commit
-
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
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
17 Jan, 2017
2 commits
-
Fix to probe on gcc generated functions on modules. Since
probing on a module is based on its symbol name, it should
be adjusted on actual symbols.E.g. without this fix, perf probe shows probe definition
on non-exist symbol as below.$ perf probe -m build-x86_64/net/netfilter/nf_nat.ko -F in_range*
in_range.isra.12
$ perf probe -m build-x86_64/net/netfilter/nf_nat.ko -D in_range
p:probe/in_range nf_nat:in_range+0With this fix, perf probe correctly shows a probe on
gcc-generated symbol.$ perf probe -m build-x86_64/net/netfilter/nf_nat.ko -D in_range
p:probe/in_range nf_nat:in_range.isra.12+0This also fixes same problem on online module as below.
$ perf probe -m i915 -D assert_plane
p:probe/assert_plane i915:assert_plane.constprop.134+0Signed-off-by: Masami Hiramatsu
Tested-by: Arnaldo Carvalho de Melo
Cc: Jiri Olsa
Cc: Namhyung Kim
Cc: Peter Zijlstra
Link: http://lkml.kernel.org/r/148411450673.9978.14905987549651656075.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo -
Fix to show correct locations for events on modules by relocating given
address instead of retrying after failure.This happens when the module text size is big enough, bigger than
sh_addr, because the original code retries with given address + sh_addr
if it failed to find CU DIE at the given address.Any address smaller than sh_addr always fails and it retries with the
correct address, but addresses bigger than sh_addr will get a CU DIE
which is on the given address (not adjusted by sh_addr).In my environment(x86-64), the sh_addr of ".text" section is 0x10030.
Since i915 is a huge kernel module, we can see this issue as below.$ grep "[Tt] .*\[i915\]" /proc/kallsyms | sort | head -n1
ffffffffc0270000 t i915_switcheroo_can_switch [i915]ffffffffc0270000 + 0x10030 = ffffffffc0280030, so we'll check
symbols cross this boundary.$ grep "[Tt] .*\[i915\]" /proc/kallsyms | grep -B1 ^ffffffffc028\
| head -n 2
ffffffffc027ff80 t haswell_init_clock_gating [i915]
ffffffffc0280110 t valleyview_init_clock_gating [i915]So setup probes on both function and see what happen.
$ sudo ./perf probe -m i915 -a haswell_init_clock_gating \
-a valleyview_init_clock_gating
Added new events:
probe:haswell_init_clock_gating (on haswell_init_clock_gating in i915)
probe:valleyview_init_clock_gating (on valleyview_init_clock_gating in i915)You can now use it in all perf tools, such as:
perf record -e probe:valleyview_init_clock_gating -aR sleep 1
$ sudo ./perf probe -l
probe:haswell_init_clock_gating (on haswell_init_clock_gating@gpu/drm/i915/intel_pm.c in i915)
probe:valleyview_init_clock_gating (on i915_vga_set_decode:4@gpu/drm/i915/i915_drv.c in i915)As you can see, haswell_init_clock_gating is correctly shown,
but valleyview_init_clock_gating is not.With this patch, both events are shown correctly.
$ sudo ./perf probe -l
probe:haswell_init_clock_gating (on haswell_init_clock_gating@gpu/drm/i915/intel_pm.c in i915)
probe:valleyview_init_clock_gating (on valleyview_init_clock_gating@gpu/drm/i915/intel_pm.c in i915)Committer notes:
In my case:
# perf probe -m i915 -a haswell_init_clock_gating -a valleyview_init_clock_gating
Added new events:
probe:haswell_init_clock_gating (on haswell_init_clock_gating in i915)
probe:valleyview_init_clock_gating (on valleyview_init_clock_gating in i915)You can now use it in all perf tools, such as:
perf record -e probe:valleyview_init_clock_gating -aR sleep 1
# perf probe -l
probe:haswell_init_clock_gating (on i915_getparam+432@gpu/drm/i915/i915_drv.c in i915)
probe:valleyview_init_clock_gating (on __i915_printk+240@gpu/drm/i915/i915_drv.c in i915)
## readelf -SW /lib/modules/4.9.0+/build/vmlinux | egrep -w '.text|Name'
[Nr] Name Type Address Off Size ES Flg Lk Inf Al
[ 1] .text PROGBITS ffffffff81000000 200000 822fd3 00 AX 0 0 4096
#So both are b0rked, now with the fix:
# perf probe -m i915 -a haswell_init_clock_gating -a valleyview_init_clock_gating
Added new events:
probe:haswell_init_clock_gating (on haswell_init_clock_gating in i915)
probe:valleyview_init_clock_gating (on valleyview_init_clock_gating in i915)You can now use it in all perf tools, such as:
perf record -e probe:valleyview_init_clock_gating -aR sleep 1
# perf probe -l
probe:haswell_init_clock_gating (on haswell_init_clock_gating@gpu/drm/i915/intel_pm.c in i915)
probe:valleyview_init_clock_gating (on valleyview_init_clock_gating@gpu/drm/i915/intel_pm.c in i915)
#Both looks correct.
Signed-off-by: Masami Hiramatsu
Tested-by: Arnaldo Carvalho de Melo
Cc: Jiri Olsa
Cc: Namhyung Kim
Cc: Peter Zijlstra
Link: http://lkml.kernel.org/r/148411436777.9978.1440275861947194930.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo
29 Sep, 2016
2 commits
-
Skip probes if the entry address of the target function is 0. This can
happen when we're handling C++ debuginfo files.E.g. without this fix, below case still fail.
----
$ ./perf probe -x /usr/lib64/libstdc++.so.6 -vD is_open
probe-definition(0): is_open
symbol:is_open file:(null) line:0 offset:0 return:0 lazy:(null)
0 arguments
symbol:catch file:(null) line:0 offset:0 return:0 lazy:(null)
symbol:throw file:(null) line:0 offset:0 return:0 lazy:(null)
symbol:rethrow file:(null) line:0 offset:0 return:0 lazy:(null)
Open Debuginfo file: /usr/lib/debug/usr/lib64/libstdc++.so.6.0.22.debug
Try to find probe point from debuginfo.
Matched function: is_open [295df]
found inline addr: 0x8ca80
Probe point found: is_open+0
found inline addr: 0x8ca70
Probe point found: is_open+0
found inline addr: 0x8ca60
Probe point found: is_open+0
Matched function: is_open [6527f]
Matched function: is_open [9fe8a]
Probe point found: is_open+0
Matched function: is_open [19710b]
found inline addr: 0xecca9
Probe point found: stdio_filebuf+57
found inline addr: 0x0
Probe point found: swap+0
Matched function: is_open [19fc9d]
Probe point found: is_open+0
Found 7 probe_trace_events.
p:probe_libstdc++/is_open /usr/lib64/libstdc++.so.6.0.22:0x8ca80
p:probe_libstdc++/is_open_1 /usr/lib64/libstdc++.so.6.0.22:0x8ca70
p:probe_libstdc++/is_open_2 /usr/lib64/libstdc++.so.6.0.22:0x8ca60
p:probe_libstdc++/is_open_3 /usr/lib64/libstdc++.so.6.0.22:0xb0ad0
p:probe_libstdc++/is_open_4 /usr/lib64/libstdc++.so.6.0.22:0xecca9
Failed to synthesize probe trace event.
Error: Failed to add events. Reason: Invalid argument (Code: -22)
----
This is because some instances have entry_pc == 0 (see 19710b and
19fc9d). With this fix, those are skipped.----
$ ./perf probe -x /usr/lib64/libstdc++.so.6 -D is_open
p:probe_libstdc++/is_open /usr/lib64/libstdc++.so.6.0.22:0x8ca80
p:probe_libstdc++/is_open_1 /usr/lib64/libstdc++.so.6.0.22:0x8ca70
p:probe_libstdc++/is_open_2 /usr/lib64/libstdc++.so.6.0.22:0x8ca60
p:probe_libstdc++/is_open_3 /usr/lib64/libstdc++.so.6.0.22:0xb0ad0
p:probe_libstdc++/is_open_4 /usr/lib64/libstdc++.so.6.0.22:0xecca9
----Signed-off-by: Masami Hiramatsu
Tested-by: Arnaldo Carvalho de Melo
Tested-by: Jiri Olsa
Cc: David Ahern
Cc: Namhyung Kim
Cc: Peter Zijlstra
Cc: Thomas Gleixner
Link: http://lkml.kernel.org/r/147464490707.29804.14277897643725143867.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo -
Ignore the error when the perf probe failed to find inline function
instances. This can happen when we search a method in C++ debuginfo. If
there is completely no instance in target, perf probe can return an
error.E.g. without this fix:
----
$ perf probe -x /usr/lib64/libstdc++.so.6 -vD showmanyc
probe-definition(0): showmanyc
symbol:showmanyc file:(null) line:0 offset:0 return:0 lazy:(null)
0 arguments
symbol:catch file:(null) line:0 offset:0 return:0 lazy:(null)
symbol:throw file:(null) line:0 offset:0 return:0 lazy:(null)
symbol:rethrow file:(null) line:0 offset:0 return:0 lazy:(null)
Open Debuginfo file: /usr/lib/debug/usr/lib64/libstdc++.so.6.0.22.debug
Try to find probe point from debuginfo.
Matched function: showmanyc
An error occurred in debuginfo analysis (-2).
Trying to use symbols.
Failed to find symbol showmanyc in /usr/lib64/libstdc++.so.6.0.22
Error: Failed to add events. Reason: No such file or directory (Code: -2)
----This is because one of showmanyc is defined as inline but no instance
found. With this fix, it is succeeded to show as below.
----
$ perf probe -x /usr/lib64/libstdc++.so.6 -D showmanyc
p:probe_libstdc++/showmanyc /usr/lib64/libstdc++.so.6.0.22:0xb0e50
p:probe_libstdc++/showmanyc_1 /usr/lib64/libstdc++.so.6.0.22:0xc7c40
p:probe_libstdc++/showmanyc_2 /usr/lib64/libstdc++.so.6.0.22:0xecfa0
p:probe_libstdc++/showmanyc_3 /usr/lib64/libstdc++.so.6.0.22:0x115fc0
p:probe_libstdc++/showmanyc_4 /usr/lib64/libstdc++.so.6.0.22:0x121a90
----Signed-off-by: Masami Hiramatsu
Tested-by: Arnaldo Carvalho de Melo
Tested-by: Jiri Olsa
Cc: David Ahern
Cc: Namhyung Kim
Cc: Peter Zijlstra
Cc: Thomas Gleixner
Link: http://lkml.kernel.org/r/147464489775.29804.3190419491209875936.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo
01 Sep, 2016
3 commits
-
Move generic dwarf related functions from util/probe-finder.c to
util/dwarf-aux.c. Functions name and their prototype are also changed
accordingly. No functionality changes.Suggested-and-Acked-by: Masami Hiramatsu
Signed-off-by: Ravi Bangoria
Cc: Alexander Shishkin
Cc: Hemant Kumar
Cc: Naveen N. Rao
Cc: Peter Zijlstra
Cc: Wang Nan
Link: http://lkml.kernel.org/r/1472546377-25612-1-git-send-email-ravi.bangoria@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo -
The function prologue prepares stack and registers before executing
function logic.When target program is compiled without optimization, function parameter
information is only valid after the prologue.When we probe entrypc of the function, and try to record a function
parameter, it contains a garbage value.For example:
$ vim test.c
#includevoid foo(int i)
{
printf("i: %d\n", i);
}int main()
{
foo(42);
return 0;
}$ gcc -g test.c -o test
$ objdump -dl test | less
foo():
/home/ravi/test.c:4
400536: 55 push %rbp
400537: 48 89 e5 mov %rsp,%rbp
40053a: 48 83 ec 10 sub -bashx10,%rsp
40053e: 89 7d fc mov %edi,-0x4(%rbp)
/home/ravi/test.c:5
400541: 8b 45 fc mov -0x4(%rbp),%eax
...
...
main():
/home/ravi/test.c:9
400558: 55 push %rbp
400559: 48 89 e5 mov %rsp,%rbp
/home/ravi/test.c:10
40055c: bf 2a 00 00 00 mov -bashx2a,%edi
400561: e8 d0 ff ff ff callq 400536$ perf probe -x ./test 'foo i'
$ cat /sys/kernel/debug/tracing/uprobe_events
p:probe_test/foo /home/ravi/test:0x0000000000000536 i=-12(%sp):s32$ perf record -e probe_test:foo ./test
$ perf script
test 5778 [001] 4918.562027: probe_test:foo: (400536) i=0Here variable 'i' is passed via stack which is pushed on stack at
0x40053e. But we are probing at 0x400536.To resolve this issues, we need to probe on next instruction after
prologue. gdb and systemtap also does same thing. I've implemented this
patch based on approach systemtap has used.After applying patch:
$ perf probe -x ./test 'foo i'
$ cat /sys/kernel/debug/tracing/uprobe_events
p:probe_test/foo /home/ravi/test:0x0000000000000541 i=-4(%bp):s32$ perf record -e probe_test:foo ./test
$ perf script
test 6300 [001] 5877.879327: probe_test:foo: (400541) i=42No need to skip prologue for optimized case since debug info is correct
for each instructions for -O2 -g. For more details please visit:https://bugzilla.redhat.com/show_bug.cgi?id=612253#c6
Changes in v2:
- Skipping prologue only when any ARG is either C variable, $params or
$vars.- Probe on line(:1) may not be always possible. Recommend only address
to force probe on function entry.Committer notes:
Testing it with 'perf trace':
# perf probe -x ./test foo i
Added new event:
probe_test:foo (on foo in /home/acme/c/test with i)You can now use it in all perf tools, such as:
perf record -e probe_test:foo -aR sleep 1
# cat /sys/kernel/debug/tracing/uprobe_events
p:probe_test/foo /home/acme/c/test:0x0000000000000526 i=-12(%sp):s32
# trace --no-sys --event probe_*:* ./test
i: 42
0.000 probe_test:foo:(400526) i=0)
#After the patch:
# perf probe -d *:*
Removed event: probe_test:foo
# perf probe -x ./test foo i
Target program is compiled without optimization. Skipping prologue.
Probe on address 0x400526 to force probing at the function entry.Added new event:
probe_test:foo (on foo in /home/acme/c/test with i)You can now use it in all perf tools, such as:
perf record -e probe_test:foo -aR sleep 1
# cat /sys/kernel/debug/tracing/uprobe_events
p:probe_test/foo /home/acme/c/test:0x0000000000000531 i=-4(%bp):s32
# trace --no-sys --event probe_*:* ./test
i: 42
0.000 probe_test:foo:(400531) i=42)
#Reported-by: Michael Petlan
Report-Link: https://www.mail-archive.com/linux-perf-users@vger.kernel.org/msg02348.html
Signed-off-by: Ravi Bangoria
Tested-by: Arnaldo Carvalho de Melo
Tested-by: Jiri Olsa
Acked-by: Masami Hiramatsu
Acked-by: Naveen N. Rao
Cc: Alexander Shishkin
Cc: Hemant Kumar
Cc: Peter Zijlstra
Cc: Wang Nan
Cc: Yauheni Kaliuta
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1299021
Link: http://lkml.kernel.org/r/1470214725-5023-2-git-send-email-ravi.bangoria@linux.vnet.ibm.com
[ Rename 'die' to 'cu_die' to avoid shadowing a die() definition on at least centos 5, Debian 7 and ubuntu:12.04.5]
[ Use PRIx64 instead of lx to format a Dwarf_Addr, aka long long unsigned int, fixing the build on 32-bit systems ]
[ dwarf_getsrclines() expects a size_t * argument ]
Signed-off-by: Arnaldo Carvalho de Melo -
Support probing on offline cross-architecture binary by adding getting
the target machine arch from ELF and choose correct register string for
the machine.Here is an example:
-----
$ perf probe --vmlinux=./vmlinux-arm --definition 'do_sys_open $params'
p:probe/do_sys_open do_sys_open+0 dfd=%r5:s32 filename=%r1:u32 flags=%r6:s32 mode=%r3:u16
-----Here, we can get probe/do_sys_open from above and append it to to the target
machine's tracing/kprobe_events file in the tracefs mountput, usually
/sys/kernel/debug/tracing/kprobe_events (or /sys/kernel/tracing/kprobe_events).Signed-off-by: Masami Hiramatsu
Cc: Jiri Olsa
Cc: Peter Zijlstra
Link: http://lkml.kernel.org/r/147214229717.23638.6440579792548044658.stgit@devbox
[ Add definition for EM_AARCH64 to fix the build on at least centos 6, debian 7 & ubuntu 12.04.5 ]
Signed-off-by: Arnaldo Carvalho de Melo
24 Aug, 2016
3 commits
-
Use hexadecimal type by default if it is available on current running
kernel.This keeps the default behavior of perf probe after changing the output
format of 'u8/16/32/64' to unsigned decimal number.Signed-off-by: Masami Hiramatsu
Cc: Alexander Shishkin
Cc: Hemant Kumar
Cc: Naohiro Aota
Cc: Peter Zijlstra
Cc: Steven Rostedt
Cc: Wang Nan
Link: http://lkml.kernel.org/r/147151074685.12957.16415861010796255514.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo -
Support hexadecimal unsigned integer casting by 'x'. This allows user
to explicitly specify the output format of the probe arguments as
hexadecimal.Signed-off-by: Masami Hiramatsu
Cc: Alexander Shishkin
Cc: Hemant Kumar
Cc: Naohiro Aota
Cc: Peter Zijlstra
Cc: Steven Rostedt
Cc: Wang Nan
Link: http://lkml.kernel.org/r/147151072679.12957.4458656416765710753.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo -
Add a checking routine what types are supported by the running kernel by
finding the pattern in /tracing/README.Signed-off-by: Masami Hiramatsu
Cc: Alexander Shishkin
Cc: Hemant Kumar
Cc: Naohiro Aota
Cc: Peter Zijlstra
Cc: Steven Rostedt
Cc: Wang Nan
Link: http://lkml.kernel.org/r/147151071172.12957.3340095690753291085.stgit@devbox
[ 'enum probe_type' has no negative entries, so ends up as 'unsigned', remove '< 0'
test to fix the build on at least centos:5, debian:7 & ubuntu:12.04.5 ]
Signed-off-by: Arnaldo Carvalho de Melo
09 Aug, 2016
1 commit
-
The 'perf probe' tool detects a variable's type and use the detected
type to add a new probe. Then, kprobes prints its variable in
hexadecimal format if the variable is unsigned and prints in decimal if
it is signed.We sometimes want to see unsigned variable in decimal format (i.e.
sector_t or size_t). In that case, we need to investigate the variable's
size manually to specify just signedness.This patch add signedness casting support. By specifying "s" or "u" as a
type, perf-probe will investigate variable size as usual and use the
specified signedness.E.g. without this:
$ perf probe -a 'submit_bio bio->bi_iter.bi_sector'
Added new event:
probe:submit_bio (on submit_bio with bi_sector=bio->bi_iter.bi_sector)
You can now use it in all perf tools, such as:
perf record -e probe:submit_bio -aR sleep 1
$ cat trace_pipe|head
dbench-9692 [003] d..1 971.096633: submit_bio: (submit_bio+0x0/0x140) bi_sector=0x3a3d00
dbench-9692 [003] d..1 971.096685: submit_bio: (submit_bio+0x0/0x140) bi_sector=0x1a3d80
dbench-9692 [003] d..1 971.096687: submit_bio: (submit_bio+0x0/0x140) bi_sector=0x3a3d80
...
// need to investigate the variable size
$ perf probe -a 'submit_bio bio->bi_iter.bi_sector:s64'
Added new event:
probe:submit_bio (on submit_bio with bi_sector=bio->bi_iter.bi_sector:s64)
You can now use it in all perf tools, such as:
perf record -e probe:submit_bio -aR sleep 1With this:
// just use "s" to cast its signedness
$ perf probe -v -a 'submit_bio bio->bi_iter.bi_sector:s'
Added new event:
probe:submit_bio (on submit_bio with bi_sector=bio->bi_iter.bi_sector:s)
You can now use it in all perf tools, such as:
perf record -e probe:submit_bio -aR sleep 1
$ cat trace_pipe|head
dbench-9689 [001] d..1 1212.391237: submit_bio: (submit_bio+0x0/0x140) bi_sector=128
dbench-9689 [001] d..1 1212.391252: submit_bio: (submit_bio+0x0/0x140) bi_sector=131072
dbench-9697 [006] d..1 1212.398611: submit_bio: (submit_bio+0x0/0x140) bi_sector=30208This commit also update perf-probe.txt to describe "types". Most parts
are based on existing documentation: Documentation/trace/kprobetrace.txtCommitter note:
Testing using 'perf trace':
# perf probe -a 'submit_bio bio->bi_iter.bi_sector'
Added new event:
probe:submit_bio (on submit_bio with bi_sector=bio->bi_iter.bi_sector)You can now use it in all perf tools, such as:
perf record -e probe:submit_bio -aR sleep 1
# trace --no-syscalls --ev probe:submit_bio
0.000 probe:submit_bio:(ffffffffac3aee00) bi_sector=0xc133c0)
3181.861 probe:submit_bio:(ffffffffac3aee00) bi_sector=0x6cffb8)
3181.881 probe:submit_bio:(ffffffffac3aee00) bi_sector=0x6cffc0)
3184.488 probe:submit_bio:(ffffffffac3aee00) bi_sector=0x6cffc8)4717.927 probe:submit_bio:(ffffffffac3aee00) bi_sector=0x4dc7a88)
4717.970 probe:submit_bio:(ffffffffac3aee00) bi_sector=0x4dc7880)
^C[root@jouet ~]#Now, using this new feature:
[root@jouet ~]# perf probe -a 'submit_bio bio->bi_iter.bi_sector:s'
Added new event:
probe:submit_bio (on submit_bio with bi_sector=bio->bi_iter.bi_sector:s)You can now use it in all perf tools, such as:
perf record -e probe:submit_bio -aR sleep 1
[root@jouet ~]# trace --no-syscalls --ev probe:submit_bio
0.000 probe:submit_bio:(ffffffffac3aee00) bi_sector=7145704)
0.017 probe:submit_bio:(ffffffffac3aee00) bi_sector=7145712)
0.019 probe:submit_bio:(ffffffffac3aee00) bi_sector=7145720)
2.567 probe:submit_bio:(ffffffffac3aee00) bi_sector=7145728)
5631.919 probe:submit_bio:(ffffffffac3aee00) bi_sector=0)
5631.941 probe:submit_bio:(ffffffffac3aee00) bi_sector=8)
5631.945 probe:submit_bio:(ffffffffac3aee00) bi_sector=16)
5631.948 probe:submit_bio:(ffffffffac3aee00) bi_sector=24)
^C#With callchains:
# trace --no-syscalls --ev probe:submit_bio/max-stack=10/
0.000 probe:submit_bio:(ffffffffac3aee00) bi_sector=50662544)
submit_bio+0xa8200001 ([kernel.kallsyms])
submit_bh+0xa8200013 ([kernel.kallsyms])
jbd2_journal_commit_transaction+0xa8200691 ([kernel.kallsyms])
kjournald2+0xa82000ca ([kernel.kallsyms])
kthread+0xa82000d8 ([kernel.kallsyms])
ret_from_fork+0xa820001f ([kernel.kallsyms])
0.023 probe:submit_bio:(ffffffffac3aee00) bi_sector=50662552)
submit_bio+0xa8200001 ([kernel.kallsyms])
submit_bh+0xa8200013 ([kernel.kallsyms])
jbd2_journal_commit_transaction+0xa8200691 ([kernel.kallsyms])
kjournald2+0xa82000ca ([kernel.kallsyms])
kthread+0xa82000d8 ([kernel.kallsyms])
ret_from_fork+0xa820001f ([kernel.kallsyms])
0.027 probe:submit_bio:(ffffffffac3aee00) bi_sector=50662560)
submit_bio+0xa8200001 ([kernel.kallsyms])
submit_bh+0xa8200013 ([kernel.kallsyms])
jbd2_journal_commit_transaction+0xa8200691 ([kernel.kallsyms])
kjournald2+0xa82000ca ([kernel.kallsyms])
kthread+0xa82000d8 ([kernel.kallsyms])
ret_from_fork+0xa820001f ([kernel.kallsyms])
2.593 probe:submit_bio:(ffffffffac3aee00) bi_sector=50662568)
submit_bio+0xa8200001 ([kernel.kallsyms])
submit_bh+0xa8200013 ([kernel.kallsyms])
journal_submit_commit_record+0xa82001ac ([kernel.kallsyms])
jbd2_journal_commit_transaction+0xa82012e8 ([kernel.kallsyms])
kjournald2+0xa82000ca ([kernel.kallsyms])
kthread+0xa82000d8 ([kernel.kallsyms])
ret_from_fork+0xa820001f ([kernel.kallsyms])
^C#Signed-off-by: Naohiro Aota
Tested-by: Arnaldo Carvalho de Melo
Cc: Alexander Shishkin
Cc: Hemant Kumar
Cc: Masami Hiramatsu
Cc: Peter Zijlstra
Cc: Wang Nan
Link: http://lkml.kernel.org/r/1470710408-23515-1-git-send-email-naohiro.aota@hgst.com
Signed-off-by: Arnaldo Carvalho de Melo
13 Jul, 2016
1 commit
-
The tools so far have been using the strerror_r() GNU variant, that
returns a string, be it the buffer passed or something else.But that, besides being tricky in cases where we expect that the
function using strerror_r() returns the error formatted in a provided
buffer (we have to check if it returned something else and copy that
instead), breaks the build on systems not using glibc, like Alpine
Linux, where musl libc is used.So, introduce yet another wrapper, str_error_r(), that has the GNU
interface, but uses the portable XSI variant of strerror_r(), so that
users rest asured that the provided buffer is used and it is what is
returned.Cc: Adrian Hunter
Cc: David Ahern
Cc: Jiri Olsa
Cc: Namhyung Kim
Cc: Wang Nan
Link: http://lkml.kernel.org/n/tip-d4t42fnf48ytlk8rjxs822tf@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo
10 May, 2016
1 commit
-
Check the return value of strbuf APIs in perf-probe
related code, so that it can handle errors in strbuf.Signed-off-by: Masami Hiramatsu
Cc: Namhyung Kim
Cc: Peter Zijlstra
Link: http://lkml.kernel.org/r/20160510054707.6158.69861.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo
28 Apr, 2016
1 commit
-
Replace many fixed-length char array with strbuf to stringify
perf_probe_event and probe_trace_event etc.Signed-off-by: Masami Hiramatsu
Signed-off-by: Masami Hiramatsu
Cc: Ananth N Mavinakayanahalli
Cc: Hemant Kumar
Cc: Namhyung Kim
Cc: Peter Zijlstra
Link: http://lkml.kernel.org/r/20160427183713.23446.97377.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo
24 Mar, 2016
1 commit
-
We have addch() for chars, add() for fixed size data, and addstr() for
variable length strings, use them.Cc: Adrian Hunter
Cc: Jiri Olsa
Cc: Masami Hiramatsu
Cc: Namhyung Kim
Cc: Wang Nan
Link: http://lkml.kernel.org/n/tip-0ap02fn2xtvpduj2j6b2o1j4@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo
03 Feb, 2016
1 commit
-
'perf probe' through debuginfo__find_probes() in util/probe-finder.c
checks for the functions' frame descriptions in either .eh_frame section
of an ELF or the .debug_frame.The check is based on whether either one of these sections is present.
Depending on distro, toolchain defaults, architetcutre, build flags,
etc., CFI might be found in either .eh_frame and/or .debug_frame.
Sometimes, it may happen that, .eh_frame, even if present, may not be
complete and may miss some descriptions.Therefore, to be sure, to find the CFI covering an address we will
always have to investigate both if available.For e.g., in powerpc, this may happen:
$ gcc -g bin.c -o bin$ objdump --dwarf ./bin
: Abbrev Number: 7 (DW_TAG_subprogram)
DW_AT_external : 1
DW_AT_name : (indirect string, offset: 0x9e): main
DW_AT_decl_file : 1
DW_AT_decl_line : 39
DW_AT_prototyped : 1
DW_AT_type :
DW_AT_low_pc : 0x100007b8If the .eh_frame and .debug_frame are checked for the same binary, we
will find that, .eh_frame (although present) doesn't contain a
description for "main" function.But, .debug_frame has a description:
000000d8 00000024 00000000 FDE cie=00000000 pc=100007b8..10000838
DW_CFA_advance_loc: 16 to 100007c8
DW_CFA_def_cfa_offset: 144
DW_CFA_offset_extended_sf: r65 at cfa+16
...Due to this (since, perf checks whether .eh_frame is present and goes on
searching for that address inside that frame), perf is unable to process
the probes:# perf probe -x ./bin main
Failed to get call frame on 0x100007b8
Error: Failed to add events.To avoid this issue, we need to check both the sections (.eh_frame and
.debug_frame), which is done in this patch.Note that, we can always force everything into both .eh_frame and
.debug_frame by:$ gcc bin.c -fasynchronous-unwind-tables -fno-dwarf2-cfi-asm -g -o bin
Signed-off-by: Hemant Kumar
Acked-by: Masami Hiramatsu
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Mark Wielaard
Cc: Naveen N. Rao
Cc: Srikar Dronamraju
Link: http://lkml.kernel.org/r/1454426806-13974-1-git-send-email-hemant@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo
26 Nov, 2015
1 commit
-
The commit 05c8d802fa52 ("perf probe: Fix to free temporal Dwarf_Frame")
tried to fix the memory leak of Dwarf_Frame, but it released the frame
at wrong point. Since the dwarf_frame_cfa(frame, &pf->fb_ops, &nops) can
return an address inside the frame data structure to pf->fb_ops, we can
not release the frame before using pf->fb_ops.This reverts the commit and releases the frame afterwards (right before
returning from call_probe_finder) correctly.Reported-and-Tested-by: Arnaldo Carvalho de Melo
Reported-by: Michael Petlan
Signed-off-by: Masami Hiramatsu
Cc: Adrian Hunter
Cc: David Ahern
Cc: Jiri Olsa
Cc: Namhyung Kim
Cc: Peter Zijlstra
Cc: Wang Nan
Fixes: 05c8d802fa52 ("perf probe: Fix to free temporal Dwarf_Frame")
LPU-Reference: 20151125103432.1473.31009.stgit@localhost.localdomain
Signed-off-by: Arnaldo Carvalho de Melo
20 Nov, 2015
1 commit
-
Since dwarf_cfi_addrframe returns malloc'd Dwarf_Frame object, it has to
be freed after it is used.Signed-off-by: Masami Hiramatsu
Cc: Adrian Hunter
Cc: Jiri Olsa
Cc: Namhyung Kim
Cc: Peter Zijlstra
Link: http://lkml.kernel.org/r/20151118064011.30709.65674.stgit@localhost.localdomain
Signed-off-by: Arnaldo Carvalho de Melo
13 Nov, 2015
2 commits
-
When probing with a glob, errors in add_probe_trace_event() won't be
passed to debuginfo__find_trace_events() because it would be modified by
probe_point_search_cb(). It causes a segfault if perf fails to find an
argument for a probe point matched by the glob. For example:# ./perf probe -v -n 'SyS_dup? oldfd'
probe-definition(0): SyS_dup? oldfd
symbol:SyS_dup? file:(null) line:0 offset:0 return:0 lazy:(null)
parsing arg: oldfd into oldfd
1 arguments
Looking at the vmlinux_path (7 entries long)
Using /lib/modules/4.3.0-rc4+/build/vmlinux for symbols
Open Debuginfo file: /lib/modules/4.3.0-rc4+/build/vmlinux
Try to find probe point from debuginfo.
Matched function: SyS_dup3
found inline addr: 0xffffffff812095c0
Probe point found: SyS_dup3+0
Searching 'oldfd' variable in context.
Converting variable oldfd into trace event.
oldfd type is long int.
found inline addr: 0xffffffff812096d4
Probe point found: SyS_dup2+36
Searching 'oldfd' variable in context.
Failed to find 'oldfd' in this function.
Matched function: SyS_dup3
Probe point found: SyS_dup3+0
Searching 'oldfd' variable in context.
Converting variable oldfd into trace event.
oldfd type is long int.
Matched function: SyS_dup2
Probe point found: SyS_dup2+0
Searching 'oldfd' variable in context.
Converting variable oldfd into trace event.
oldfd type is long int.
Found 4 probe_trace_events.
Opening /sys/kernel/debug/tracing//kprobe_events write=1
Writing event: p:probe/SyS_dup3 _text+2135488 oldfd=%di:s64
Segmentation fault (core dumped)
#This patch ensures that add_probe_trace_event() doesn't touches
tf->ntevs and tf->tevs if those functions fail.After the patch:
# perf probe 'SyS_dup? oldfd'
Failed to find 'oldfd' in this function.
Added new events:
probe:SyS_dup3 (on SyS_dup? with oldfd)
probe:SyS_dup3_1 (on SyS_dup? with oldfd)
probe:SyS_dup2 (on SyS_dup? with oldfd)You can now use it in all perf tools, such as:
perf record -e probe:SyS_dup2 -aR sleep 1
Signed-off-by: Wang Nan
Tested-by: Arnaldo Carvalho de Melo
Cc: Alexei Starovoitov
Cc: Masami Hiramatsu
Cc: Zefan Li
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1447417761-156094-3-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo -
Fix memory leaking on the debuginfo__find_trace_events() failure path
which frees an array of probe_trace_events but doesn't clears all the
allocated sub-structures and strings.So, before doing zfree(tevs), clear all the array elements which may
have allocated resources.Reported-by: Wang Nan
Signed-off-by: Masami Hiramatsu
Cc: Alexei Starovoitov
Cc: Zefan Li
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1447417761-156094-2-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo
01 Oct, 2015
3 commits
-
perf probe shows more precisely message when it finds given
%return target function is inlined.Without this fix:
----
# ./perf probe -V getname_flags%return
Return probe must be on the head of a real function.
Debuginfo analysis failed.
Error: Failed to show vars.
----With this fix:
----
# ./perf probe -V getname_flags%return
Failed to find "getname_flags%return",
because getname_flags is an inlined function and has no return point.
Debuginfo analysis failed.
Error: Failed to show vars.
----Suggested-by: Arnaldo Carvalho de Melo
Signed-off-by: Masami Hiramatsu
Tested-by: Arnaldo Carvalho de Melo
Cc: Jiri Olsa
Cc: Namhyung Kim
Cc: Wang Nan
Link: http://lkml.kernel.org/r/20150930164137.3733.55055.stgit@localhost.localdomain
Signed-off-by: Arnaldo Carvalho de Melo -
Perf probe always failed to find appropriate line numbers because of
failing to find .text start address offset from debuginfo.e.g.
----
# ./perf probe -m pcspkr pcspkr_event:5
Added new events:
probe:pcspkr_event (on pcspkr_event:5 in pcspkr)
probe:pcspkr_event_1 (on pcspkr_event:5 in pcspkr)You can now use it in all perf tools, such as:
perf record -e probe:pcspkr_event_1 -aR sleep 1
# ./perf probe -l
Failed to find debug information for address ffffffffa031f006
Failed to find debug information for address ffffffffa031f016
probe:pcspkr_event (on pcspkr_event+6 in pcspkr)
probe:pcspkr_event_1 (on pcspkr_event+22 in pcspkr)
----This fixes the above issue as below.
1. Get the relative address of the symbol in .text by using
map->start.
2. Adjust the address by adding the offset of .text section
in the kernel module binary.With this fix, perf probe -l shows lines correctly.
----
# ./perf probe -l
probe:pcspkr_event (on pcspkr_event:5@drivers/input/misc/pcspkr.c in pcspkr)
probe:pcspkr_event_1 (on pcspkr_event:5@drivers/input/misc/pcspkr.c in pcspkr)
----Reported-by: Arnaldo Carvalho de Melo
Signed-off-by: Masami Hiramatsu
Tested-by: Arnaldo Carvalho de Melo
Cc: Jiri Olsa
Cc: Namhyung Kim
Cc: Wang Nan
Link: http://lkml.kernel.org/r/20150930164132.3733.24643.stgit@localhost.localdomain
Signed-off-by: Arnaldo Carvalho de Melo -
Fix a trival bug about libdwfl usage of the report session, it should
explicitly begin and end a report session around dwfl_report_offline().Signed-off-by: Masami Hiramatsu
Cc: Jiri Olsa
Cc: Namhyung Kim
Cc: Wang Nan
Link: http://lkml.kernel.org/r/20150930164128.3733.59876.stgit@localhost.localdomain
Signed-off-by: Arnaldo Carvalho de Melo
26 Aug, 2015
1 commit
-
It should be useful to allow 'perf probe' probe at absolute offset of a
target. For example, when (u)probing at a instruction of a shared object
in a embedded system where debuginfo is not avaliable but we know the
offset of that instruction by manually digging.This patch enables following perf probe command syntax:
# perf probe 0xffffffff811e6615
And
# perf probe /lib/x86_64-linux-gnu/libc-2.19.so 0xeb860
In the above example, we don't need a anchor symbol, so it is possible
to compute absolute addresses using other methods and then use 'perf
probe' to create the probing points.v1 -> v2:
Drop the leading '+' in cmdline;
Allow uprobing at offset 0x0;
Improve 'perf probe -l' result when uprobe at area without debuginfo.v2 -> v3:
Split bugfix to a separated patch.Test result:
# perf probe 0xffffffff8119d175 %ax
# perf probe sys_write %ax
# perf probe /lib64/libc-2.18.so 0x0 %ax
# perf probe /lib64/libc-2.18.so 0x5 %ax
# perf probe /lib64/libc-2.18.so 0xd8e40 %ax
# perf probe /lib64/libc-2.18.so __write %ax
# perf probe /lib64/libc-2.18.so 0xd8e49 %ax
# cat /sys/kernel/debug/tracing/uprobe_eventsp:probe_libc/abs_0 /lib64/libc-2.18.so:0x (null) arg1=%ax
p:probe_libc/abs_5 /lib64/libc-2.18.so:0x0000000000000005 arg1=%ax
p:probe_libc/abs_d8e40 /lib64/libc-2.18.so:0x00000000000d8e40 arg1=%ax
p:probe_libc/__write /lib64/libc-2.18.so:0x00000000000d8e40 arg1=%ax
p:probe_libc/abs_d8e49 /lib64/libc-2.18.so:0x00000000000d8e49 arg1=%ax# cat /sys/kernel/debug/tracing/kprobe_events
p:probe/abs_ffffffff8119d175 0xffffffff8119d175 arg1=%ax
p:probe/sys_write _text+1692016 arg1=%ax# perf probe -l
Failed to find debug information for address 5
probe:abs_ffffffff8119d175 (on sys_write+5 with arg1)
probe:sys_write (on sys_write with arg1)
probe_libc:__write (on @unix/syscall-template.S:81 in /lib64/libc-2.18.so with arg1)
probe_libc:abs_0 (on 0x0 in /lib64/libc-2.18.so with arg1)
probe_libc:abs_5 (on 0x5 in /lib64/libc-2.18.so with arg1)
probe_libc:abs_d8e40 (on @unix/syscall-template.S:81 in /lib64/libc-2.18.so with arg1)
probe_libc:abs_d8e49 (on __GI___libc_write+9 in /lib64/libc-2.18.so with arg1)Signed-off-by: Wang Nan
Acked-by: Masami Hiramatsu
Cc: Namhyung Kim
Cc: Steven Rostedt
Cc: Zefan Li
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1440586666-235233-7-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo
20 Jul, 2015
1 commit
-
So that we can pass more info to strlist__new() without having to change
its function signature, just adding entries to the strlist_config struct
with sensible defaults for when those fields are not specified.Cc: Adrian Hunter
Cc: Borislav Petkov
Cc: David Ahern
Cc: Frederic Weisbecker
Cc: Jiri Olsa
Cc: Namhyung Kim
Cc: Stephane Eranian
Link: http://lkml.kernel.org/n/tip-5uaaler4931i0s9sedxjquhq@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo
08 Jun, 2015
1 commit
-
This has a different model than the 'thread' and 'map' struct lifetimes:
there is not a definitive "don't use this DSO anymore" event, i.e. we may
get many 'struct map' holding references to the '/usr/lib64/libc-2.20.so'
DSO but then at some point some DSO may have no references but we still
don't want to straight away release its resources, because "soon" we may
get a new 'struct map' that needs it and we want to reuse its symtab or
other resources.So we need some way to garbage collect it when crossing some memory
usage threshold, which is left for anoter patch, for now it is
sufficient to release it when calling dsos__exit(), i.e. when deleting
the whole list as part of deleting the 'struct machine' containing it,
which will leave only referenced objects being used.Cc: Adrian Hunter
Cc: David Ahern
Cc: Jiri Olsa
Cc: Namhyung Kim
Link: http://lkml.kernel.org/n/tip-majzgz07cm90t2tejrjy4clf@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo
14 May, 2015
1 commit
-
perf probe currently errors out if there are any tail calls to probed
functions:[root@rhel71be]# perf probe do_fork
Failed to find probe point in any functions.
Error: Failed to add events.Fix this by teaching perf to ignore tail calls.
Without patch:
[root@rhel71be perf]# ./perf probe -v do_fork
probe-definition(0): do_fork symbol:do_fork file:(null) line:0 offset:0
return:0 lazy:(null)
0 arguments
Looking at the vmlinux_path (7 entries long)
symsrc__init: build id mismatch for /boot/vmlinux.
Using /usr/lib/debug/lib/modules/3.10.0-201.el7.ppc64/vmlinux for symbols
Open Debuginfo file:
/usr/lib/debug/lib/modules/3.10.0-201.el7.ppc64/vmlinux
Try to find probe point from debuginfo.
found inline addr: 0xc0000000000bb9b0
Probe point found: do_fork+0
found inline addr: 0xc0000000000bbe20
Probe point found: kernel_thread+48
found inline addr: 0xc0000000000bbe5c
Probe point found: sys_fork+28
found inline addr: 0xc0000000000bbfac
Probe point found: sys_vfork+44
found inline addr: 0xc0000000000bc27c
Failed to find probe point in any functions.
An error occurred in debuginfo analysis (-2).
Error: Failed to add events. Reason: No such file or directory (Code: -2)With patch:
[root@rhel71be perf]# ./perf probe -v do_fork
probe-definition(0): do_fork symbol:do_fork file:(null) line:0 offset:0
return:0 lazy:(null)
0 arguments
Looking at the vmlinux_path (7 entries long)
symsrc__init: build id mismatch for /boot/vmlinux.
Using /usr/lib/debug/lib/modules/3.10.0-201.el7.ppc64/vmlinux for symbols
Open Debuginfo file:
/usr/lib/debug/lib/modules/3.10.0-201.el7.ppc64/vmlinux
Try to find probe point from debuginfo.
found inline addr: 0xc0000000000bb9b0
Probe point found: do_fork+0
found inline addr: 0xc0000000000bbe20
Probe point found: kernel_thread+48
found inline addr: 0xc0000000000bbe5c
Probe point found: sys_fork+28
found inline addr: 0xc0000000000bbfac
Probe point found: sys_vfork+44
found inline addr: 0xc0000000000bc27c
Ignoring tail call from SyS_clone
Found 4 probe_trace_events.
Opening /sys/kernel/debug/tracing/kprobe_events write=1
No kprobe blacklist support, ignored
Added new events:
Writing event: p:probe/do_fork _text+768432
Failed to write event: Invalid argument
Error: Failed to add events. Reason: Invalid argument (Code: -22)[Ignore the error about failure to write event - this kernel is missing
a patch to resolve _text properly]The reason to ignore tail calls is that the address does not belong to
any function frame. In the example above, the address in SyS_clone is
0xc0000000000bc27c, but looking at the debug-info:: Abbrev Number: 133 (DW_TAG_subprogram)
DW_AT_external : 1
DW_AT_name : (indirect string, offset: 0x3cea3): SyS_clone
DW_AT_decl_file : 7
DW_AT_decl_line : 1689
DW_AT_prototyped : 1
DW_AT_type :
DW_AT_low_pc : 0xc0000000000bc270
DW_AT_high_pc : 0xc
DW_AT_frame_base : 1 byte block: 9c (DW_OP_call_frame_cfa)
DW_AT_GNU_all_call_sites: 1
DW_AT_sibling :: Abbrev Number: 125 (DW_TAG_GNU_call_site)
DW_AT_low_pc : 0xc0000000000bc27c
DW_AT_GNU_tail_call: 1
DW_AT_abstract_origin:The frame ends at 0xc0000000000bc27c. I suppose this is why this
particular call is a "tail" call. FWIW, systemtap seems to ignore these
as well and requires users to explicitly place probes at these call
sites if necessary. I print out the caller so that users know.Signed-off-by: Naveen N. Rao
Acked-by: Masami Hiramatsu
Link: http://lkml.kernel.org/r/1430394151-15928-1-git-send-email-naveen.n.rao@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo
12 May, 2015
3 commits
-
Indicate to check variable location range in error message when we got
failed to find the variable.Before this patch:
$ perf probe --add 'generic_perform_write+118 bytes'
Failed to find the location of bytes at this address.
Perhaps, it has been optimized out.
Error: Failed to add events.After this patch:
$ perf probe --add 'generic_perform_write+118 bytes'
Failed to find the location of the 'bytes' variable at this address.
Perhaps it has been optimized out.
Use -V with the --range option to show 'bytes' location range.
Error: Failed to add events.Signed-off-by: He Kuang
Acked-by: Masami Hiramatsu
Cc: Jiri Olsa
Cc: Peter Zijlstra
Cc: Wang Nan
Link: http://lkml.kernel.org/r/1431336304-16863-3-git-send-email-hekuang@huawei.com
[ Improve the error message based on lkml thread ]
Signed-off-by: Arnaldo Carvalho de Melo -
It is not easy for users to get the accurate byte offset or the line
number where a local variable can be probed.With '--range' option, local variables in the scope of the probe point
are showed with a byte offset range, and can be added according to this
range information.For example, there are some variables in the function
generic_perform_write():
0 ssize_t generic_perform_write(struct file *file,
1 struct iov_iter *i, loff_t pos)
2 {
3 struct address_space *mapping = file->f_mapping;
4 const struct address_space_operations *a_ops = mapping->a_ops;
...
42 status = a_ops->write_begin(file, mapping, pos, bytes, flags,
&page, &fsdata);
44 if (unlikely(status < 0))But we fail when we try to probe the variable 'a_ops' at line 42 or 44.
$ perf probe --add 'generic_perform_write:42 a_ops'
Failed to find the location of a_ops at this address.
Perhaps, it has been optimized out.This is because the source code do not match the assembly, so a variable
may not be available in the source code line where it appears.After this patch, we can lookup the accurate byte offset range of a
variable, 'INV' indicates that this variable is not valid at the given
point, but available in the scope:$ perf probe --vars 'generic_perform_write:42' --range
Available variables at generic_perform_write:42
@
[INV] ssize_t written @
[INV] struct address_space_operations* a_ops @
[VAL] (unknown_type) fsdata @
[VAL] loff_t pos @
[VAL] long int status @
[VAL] long unsigned int bytes @
[VAL] struct address_space* mapping @
[VAL] struct iov_iter* i @
[VAL] struct page* page @Then it is more clear for us to add a probe with this variable:
$ perf probe --add 'generic_perform_write+170 a_ops'
Added new event:
probe:generic_perform_write (on generic_perform_write+170 with a_ops)Signed-off-by: He Kuang
Acked-by: Masami Hiramatsu
Cc: Jiri Olsa
Cc: Peter Zijlstra
Cc: Wang Nan
Link: http://lkml.kernel.org/r/1431336304-16863-2-git-send-email-hekuang@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo -
Use struct strbuf instead of bare char[] to remove the length limitation
of variables in variable_list, so they will not disappear due to
overlength, and make preparation for adding more description for
variables.Signed-off-by: He Kuang
Acked-by: Masami Hiramatsu
Cc: Jiri Olsa
Cc: Peter Zijlstra
Cc: Wang Nan
Link: http://lkml.kernel.org/r/1431336304-16863-1-git-send-email-hekuang@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo
11 May, 2015
1 commit
-
Conflicts:
tools/perf/builtin-kmem.cSigned-off-by: Ingo Molnar
09 May, 2015
4 commits
-
Support glob wildcards for function name when adding new probes. This
will allow us to build caches of function-entry level information with
$params.e.g.
----
# perf probe --no-inlines --add 'kmalloc* $params'
Added new events:
probe:kmalloc_slab (on kmalloc* with $params)
probe:kmalloc_large_node (on kmalloc* with $params)
probe:kmalloc_order_trace (on kmalloc* with $params)You can now use it in all perf tools, such as:
perf record -e probe:kmalloc_order_trace -aR sleep 1
# perf probe --list
probe:kmalloc_large_node (on kmalloc_large_node@mm/slub.c with size flags node)
probe:kmalloc_order_trace (on kmalloc_order_trace@mm/slub.c with size flags order)
probe:kmalloc_slab (on kmalloc_slab@mm/slab_common.c with size flags)
----Signed-off-by: Masami Hiramatsu
Tested-by: Arnaldo Carvalho de Melo
Cc: Ananth N Mavinakayanahalli
Cc: David Ahern
Cc: Hemant Kumar
Cc: Jiri Olsa
Cc: Namhyung Kim
Cc: Peter Zijlstra
Link: http://lkml.kernel.org/r/20150508010335.24812.19972.stgit@localhost.localdomain
Signed-off-by: Arnaldo Carvalho de Melo -
Add --no-inlines(--inlines) option to avoid searching inline functions.
Searching all functions which matches glob pattern can take a long time
and find a lot of inline functions.With this option perf-probe searches target on the non-inlined
functions.Signed-off-by: Masami Hiramatsu
Cc: Ananth N Mavinakayanahalli
Cc: David Ahern
Cc: Hemant Kumar
Cc: Jiri Olsa
Cc: Namhyung Kim
Cc: Peter Zijlstra
Link: http://lkml.kernel.org/r/20150508010333.24812.86568.stgit@localhost.localdomain
Signed-off-by: Arnaldo Carvalho de Melo -
Introduce probe_conf global configuration parameters for probe-event and
probe-finder, and removes related parameters from APIs.Signed-off-by: Masami Hiramatsu
Cc: Ananth N Mavinakayanahalli
Cc: David Ahern
Cc: Hemant Kumar
Cc: Jiri Olsa
Cc: Namhyung Kim
Cc: Peter Zijlstra
Link: http://lkml.kernel.org/r/20150508010330.24812.21095.stgit@localhost.localdomain
Signed-off-by: Arnaldo Carvalho de Melo -
$params is similar to $vars but matches only function parameters not
local variables.Thus, this is useful for tracing function parameter changing or tracing
function call with parameters.Testing it:
# perf probe tcp_sendmsg '$params'
Added new event:
probe:tcp_sendmsg (on tcp_sendmsg with $params)You can now use it in all perf tools, such as:
perf record -e probe:tcp_sendmsg -aR sleep 1
# perf probe -l
probe:tcp_sendmsg (on tcp_sendmsg@acme/git/linux/net/ipv4/tcp.c with iocb sk msg size)
# perf record -a -e probe:*
press some random letters to generate TCP (sshd) traffic...^C[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.223 MB perf.data (6 samples) ]# perf script
sshd 6385 [2] 3.907529: probe:tcp_sendmsg: iocb=0xffff8800ac4cfe70 sk=0xffff88042196c140 msg=0xffff8800ac4cfda8 size=0x24
sshd 6385 [2] 4.138973: probe:tcp_sendmsg: iocb=0xffff8800ac4cfe70 sk=0xffff88042196c140 msg=0xffff8800ac4cfda8 size=0x24
sshd 6385 [2] 4.378966: probe:tcp_sendmsg: iocb=0xffff8800ac4cfe70 sk=0xffff88042196c140 msg=0xffff8800ac4cfda8 size=0x24
sshd 6385 [2] 4.603681: probe:tcp_sendmsg: iocb=0xffff8800ac4cfe70 sk=0xffff88042196c140 msg=0xffff8800ac4cfda8 size=0x24
sshd 6385 [2] 4.818455: probe:tcp_sendmsg: iocb=0xffff8800ac4cfe70 sk=0xffff88042196c140 msg=0xffff8800ac4cfda8 size=0x24
sshd 6385 [2] 5.043603: probe:tcp_sendmsg: iocb=0xffff8800ac4cfe70 sk=0xffff88042196c140 msg=0xffff8800ac4cfda8 size=0x24
# cat /sys/kernel/debug/tracing/events/probe/tcp_sendmsg/format
name: tcp_sendmsg
ID: 1927
format:
field:unsigned short common_type; offset:0; size:2; signed:0;
field:unsigned char common_flags; offset:2; size:1; signed:0;
field:unsigned char common_preempt_count; offset:3; size:1; signed:0;
field:int common_pid; offset:4; size:4; signed:1;field:unsigned long __probe_ip; offset:8; size:8; signed:0;
field:u64 iocb; offset:16; size:8; signed:0;
field:u64 sk; offset:24; size:8; signed:0;
field:u64 msg; offset:32; size:8; signed:0;
field:u64 size; offset:40; size:8; signed:0;print fmt: "(%lx) iocb=0x%Lx sk=0x%Lx msg=0x%Lx size=0x%Lx", REC->__probe_ip, REC->iocb, REC->sk, REC->msg, REC->size
#Do some system wide tracing of this probe + write syscalls:
# perf trace -e write --ev probe:* --filter-pids 6385
462.612 (0.010 ms): bash/19153 write(fd: 1, buf: 0x7f7556c78000, count: 29 ) = 29
462.701 (0.027 ms): sshd/19152 write(fd: 3, buf: 0x7f78dd12e160, count: 68 ) ...
462.701 ( ): probe:tcp_sendmsg:(ffffffff8163db30) iocb=0xffff8803ebec7e70 sk=0xffff88042196ab80 msg=0xffff8803ebec7da8 size=0x44)
462.710 (0.035 ms): sshd/19152 ... [continued]: write()) = 68
462.787 (0.009 ms): bash/19153 write(fd: 2, buf: 0x7f7556c77000, count: 22 ) = 22
462.865 (0.002 ms): sshd/19152 write(fd: 3, buf: 0x7f78dd12e160, count: 68 ) ...
462.865 ( ): probe:tcp_sendmsg:(ffffffff8163db30) iocb=0xffff8803ebec7e70 sk=0xffff88042196ab80 msg=0xffff8803ebec7da8 size=0x44)
462.873 (0.010 ms): sshd/19152 ... [continued]: write()) = 68Signed-off-by: Masami Hiramatsu
Tested-by: Arnaldo Carvalho de Melo
Cc: Ananth N Mavinakayanahalli
Cc: David Ahern
Cc: Hemant Kumar
Cc: Jiri Olsa
Cc: Namhyung Kim
Cc: Peter Zijlstra
Link: http://lkml.kernel.org/r/20150506124653.4961.59806.stgit@localhost.localdomain
[ Add some examples to the changelog message showing how to use it ]
Signed-off-by: Arnaldo Carvalho de Melo
07 May, 2015
1 commit
-
Pull perf fixes from Ingo Molnar:
"Mostly tooling fixes, but also an uncore PMU driver fix and an uncore
PMU driver hardware-enablement addition"* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf probe: Fix segfault if passed with ''.
perf report: Fix -T/--threads option to work again
perf bench numa: Fix immediate meeting of convergence condition
perf bench numa: Fixes of --quiet argument
perf bench futex: Fix hung wakeup tasks after requeueing
perf probe: Fix bug with global variables handling
perf top: Fix a segfault when kernel map is restricted.
tools lib traceevent: Fix build failure on 32-bit arch
perf kmem: Fix compiles on RHEL6/OL6
tools lib api: Undefine _FORTIFY_SOURCE before setting it
perf kmem: Consistently use PRIu64 for printing u64 values
perf trace: Disable events and drain events when forked workload ends
perf trace: Enable events when doing system wide tracing and starting a workload
perf/x86/intel/uncore: Move PCI IDs for IMC to uncore driver
perf/x86/intel/uncore: Add support for Intel Haswell ULT (lower power Mobile Processor) IMC uncore PMUs
perf/x86/intel: Add cpu_(prepare|starting|dying) for core_pmu
