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Groups > linux.kernel > #1389154
| From | Arnaldo Carvalho de Melo <acme@kernel.org> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH 25/30] perf probe: Fix offline module name missmatch issue |
| Date | 2016-04-27 16:40 +0200 |
| Message-ID | <rsyNe-2L2-73@gated-at.bofh.it> (permalink) |
| References | <rsyNc-2L2-15@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
From: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Perf can add a probe on kernel module which has not been loaded yet.
The current implementation finds the module name from path. But if the
filename is different from the actual module name then perf fails to
register a probe while loading module because of mismatch in the names.
For example, samples/kobject/kobject-example.ko is loaded as
kobject_example.
Before applying patch:
$ sudo ./perf probe -m /linux/samples/kobject/kobject-example.ko foo_show
Added new event:
probe:foo_show (on foo_show in kobject-example)
You can now use it in all perf tools, such as:
perf record -e probe:foo_show -aR sleep 1
$ cat /sys/kernel/debug/tracing/kprobe_events
p:probe/foo_show kobject-example:foo_show
$ insmod kobject-example.ko
$ lsmod
Module Size Used by
kobject_example 16384 0
Generate read to /sys/kernel/kobject_example/foo while recording data
with below command
$ sudo ./perf record -e probe:foo_show -a
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.093 MB perf.data ]
$./perf report --stdio -F overhead,comm,dso,sym
Error:
The perf.data.old file has no samples!
After applying patch:
$ sudo ./perf probe -m /linux/samples/kobject/kobject-example.ko foo_show
Added new event:
probe:foo_show (on foo_show in kobject_example)
You can now use it in all perf tools, such as:
perf record -e probe:foo_show -aR sleep 1
$ sudo cat /sys/kernel/debug/tracing/kprobe_events
p:probe/foo_show kobject_example:foo_show
$ insmod kobject-example.ko
$ lsmod
Module Size Used by
kobject_example 16384 0
Generate read to /sys/kernel/kobject_example/foo while recording data
with below command
$ sudo ./perf record -e probe:foo_show -a
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.097 MB perf.data (8 samples) ]
$ sudo ./perf report --stdio -F overhead,comm,dso,sym
...
# Samples: 8 of event 'probe:foo_show'
# Event count (approx.): 8
#
# Overhead Command Shared Object Symbol
# ........ ....... ................. ............
#
100.00% cat [kobject_example] [k] foo_show
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1461680741-12517-2-git-send-email-ravi.bangoria@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/util/probe-event.c | 19 +++++--------------
1 file changed, 5 insertions(+), 14 deletions(-)
diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index 0de5d10dda71..bc2eb7cda2d1 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -588,32 +588,23 @@ static int add_module_to_probe_trace_events(struct probe_trace_event *tevs,
int ntevs, const char *module)
{
int i, ret = 0;
- char *tmp;
+ char *mod_name = NULL;
if (!module)
return 0;
- tmp = strrchr(module, '/');
- if (tmp) {
- /* This is a module path -- get the module name */
- module = strdup(tmp + 1);
- if (!module)
- return -ENOMEM;
- tmp = strchr(module, '.');
- if (tmp)
- *tmp = '\0';
- tmp = (char *)module; /* For free() */
- }
+ mod_name = find_module_name(module);
for (i = 0; i < ntevs; i++) {
- tevs[i].point.module = strdup(module);
+ tevs[i].point.module =
+ strdup(mod_name ? mod_name : module);
if (!tevs[i].point.module) {
ret = -ENOMEM;
break;
}
}
- free(tmp);
+ free(mod_name);
return ret;
}
--
2.5.5
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[GIT PULL 00/30] perf/core improvements and fixes Arnaldo Carvalho de Melo <acme@kernel.org> - 2016-04-27 16:40 +0200 [PATCH 15/30] perf evlist: Enforce ring buffer reading Arnaldo Carvalho de Melo <acme@kernel.org> - 2016-04-27 16:40 +0200 [PATCH 30/30] perf tools: Set the maximum allowed stack from /proc/sys/kernel/perf_event_max_stack Arnaldo Carvalho de Melo <acme@kernel.org> - 2016-04-27 16:40 +0200 [PATCH 03/30] perf trace: Make --pf maj/min/all use callchains too Arnaldo Carvalho de Melo <acme@kernel.org> - 2016-04-27 16:40 +0200 [PATCH 05/30] perf trace: Make --event honour --min-stack too Arnaldo Carvalho de Melo <acme@kernel.org> - 2016-04-27 16:40 +0200 [PATCH 17/30] perf tools: Add lsdir() helper to read a directory Arnaldo Carvalho de Melo <acme@kernel.org> - 2016-04-27 16:40 +0200 [PATCH 13/30] perf intel-pt: Fix off-by-one comparison on maximum code Arnaldo Carvalho de Melo <acme@kernel.org> - 2016-04-27 16:40 +0200 [PATCH 25/30] perf probe: Fix offline module name missmatch issue Arnaldo Carvalho de Melo <acme@kernel.org> - 2016-04-27 16:40 +0200 [PATCH 21/30] perf trace: Do not beautify the 'pid' parameter as a simple integer Arnaldo Carvalho de Melo <acme@kernel.org> - 2016-04-27 16:40 +0200 [PATCH 29/30] perf core: Allow setting up max frame stack depth via sysctl Arnaldo Carvalho de Melo <acme@kernel.org> - 2016-04-27 16:40 +0200 [PATCH 26/30] perf probe: Fix module probe issue if no dwarf support Arnaldo Carvalho de Melo <acme@kernel.org> - 2016-04-27 16:50 +0200 [PATCH 14/30] perf hists: Clear dummy entry accumulated period Arnaldo Carvalho de Melo <acme@kernel.org> - 2016-04-27 16:50 +0200 [PATCH 16/30] perf probe: Close target file on error path Arnaldo Carvalho de Melo <acme@kernel.org> - 2016-04-27 16:50 +0200 [PATCH 09/30] tools build: Fix perf_clean target Arnaldo Carvalho de Melo <acme@kernel.org> - 2016-04-27 16:50 +0200 [PATCH 08/30] perf tools: Make the x86 clean quiet Arnaldo Carvalho de Melo <acme@kernel.org> - 2016-04-27 16:50 +0200 [PATCH 12/30] perf bench futex: Simplify wrapper for LOCK_PI Arnaldo Carvalho de Melo <acme@kernel.org> - 2016-04-27 16:50 +0200 [PATCH 20/30] perf trace: Move perf_flags beautifier to tools/perf/trace/beauty/ Arnaldo Carvalho de Melo <acme@kernel.org> - 2016-04-27 16:50 +0200 [PATCH 27/30] perf tools: Update x86's syscall_64.tbl, adding preadv2 & pwritev2 Arnaldo Carvalho de Melo <acme@kernel.org> - 2016-04-27 16:50 +0200 [PATCH 04/30] perf script: Fix segfault when printing callchains Arnaldo Carvalho de Melo <acme@kernel.org> - 2016-04-27 16:50 +0200 [PATCH 19/30] perf probe: Set default kprobe group name if it is not given Arnaldo Carvalho de Melo <acme@kernel.org> - 2016-04-27 16:50 +0200 [PATCH 10/30] perf tools: Remove duplicate const qualifier Arnaldo Carvalho de Melo <acme@kernel.org> - 2016-04-27 16:50 +0200 [PATCH 18/30] perf probe: Let probe_file__add_event return 0 if succeeded Arnaldo Carvalho de Melo <acme@kernel.org> - 2016-04-27 16:50 +0200 [PATCH 11/30] perf tests: Replace assignment with comparison on assert check Arnaldo Carvalho de Melo <acme@kernel.org> - 2016-04-27 16:50 +0200 [PATCH 06/30] perf trace: Make --pf honour --min-stack too Arnaldo Carvalho de Melo <acme@kernel.org> - 2016-04-27 16:50 +0200 [PATCH 02/30] perf trace: Extract evsel contructor from perf_evlist__add_pgfault Arnaldo Carvalho de Melo <acme@kernel.org> - 2016-04-27 16:50 +0200 [PATCH 28/30] perf bench: Remove one more die() call Arnaldo Carvalho de Melo <acme@kernel.org> - 2016-04-27 16:50 +0200 [PATCH 01/30] perf buildid: Fix off-by-one in write_buildid() Arnaldo Carvalho de Melo <acme@kernel.org> - 2016-04-27 16:50 +0200 Re: [GIT PULL 00/30] perf/core improvements and fixes Ingo Molnar <mingo@kernel.org> - 2016-04-27 17:10 +0200
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