BMC/Intel-BMC/linux.git/tools/perf/util/probe-event.c, branch dev

perf probe: Fix failure to probe events on arm

2015-06-23T21:21:44+00:00

Fix failure to probe events on arm, the problem was introduced by commit 5a51fcd1f30c ("perf probe: Skip kernel symbols which is out of .text"). For some architectures, the '_etext' label is not in the .text section (in the .notes section for arm/arm64). Labels out of the .text section are not loaded as symbols and we get a zero value when looking up its addresses, which causes all events to be wrongly skipped. This patch skips checking the text address range when failing to get the address of '_etext' and thus fixes the problem. The problem can be reproduced on arm as follows: # perf probe --add='generic_perform_write' generic_perform_write+0 is out of .text, skip it. Probe point 'generic_perform_write' not found. Error: Failed to add events. After this patch: # perf probe --add='generic_perform_write' Added new event: probe:generic_perform_write (on generic_perform_write) You can now use it in all perf tools, such as: perf record -e probe:generic_perform_write -aR sleep 1 Signed-off-by: He Kuang Acked-by: Masami Hiramatsu Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Wang Nan Link: http://lkml.kernel.org/r/1434595750-129791-1-git-send-email-hekuang@huawei.com Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Speed up perf probe --list by caching debuginfo

2015-06-17T19:37:53+00:00

Speed up the "perf probe --list" by caching the last used debuginfo. perf probe --list always open and load debuginfo for each entry of probe list. This takes very a long time. E.g. with vfs_* events (total 96 probes) [root@localhost perf]# time ./perf probe -l &> /dev/null real 0m25.376s user 0m24.381s sys 0m1.012s To solve this issue, this adds debuginfo_cache to cache the last used debuginfo on memory. With this fix, the perf-probe --list significantly improves its speed. [root@localhost perf]# time ./perf probe -l &> /dev/null real 0m0.161s user 0m0.136s sys 0m0.025s Signed-off-by: Masami Hiramatsu Tested-by: Arnaldo Carvalho de Melo Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Naohiro Aota Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20150617145854.19715.15314.stgit@localhost.localdomain Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Show usage even if the last event is skipped

2015-06-17T19:31:42+00:00

When the last part of converted events are blacklisted or out-of-text, those are skipped and perf probe doesn't show usage examples. This fixes it to show the example even if the last part of event list is skipped. E.g. without this patch, events are added, but suddenly end: # perf probe vfs_* vfs_caches_init_early is out of .text, skip it. vfs_caches_init is out of .text, skip it. Added new events: probe:vfs_fallocate (on vfs_*) probe:vfs_open (on vfs_*) ... probe:vfs_dentry_acceptable (on vfs_*) probe:vfs_load_quota_inode (on vfs_*) # With this fix: # perf probe vfs_* vfs_caches_init_early is out of .text, skip it. vfs_caches_init is out of .text, skip it. Added new events: probe:vfs_fallocate (on vfs_*) ... probe:vfs_load_quota_inode (on vfs_*) You can now use it in all perf tools, such as: perf record -e probe:vfs_load_quota_inode -aR sleep 1 Note that this can be reproduced ONLY IF the vfs_caches_init* is the last part of matched symbol list. I've checked this happens on "3.19.0-generic #18-Ubuntu" kernel binary. Signed-off-by: Masami Hiramatsu Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Naohiro Aota Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20150616115057.19906.5502.stgit@localhost.localdomain Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Fix to return error if no probe is added

2015-06-16T14:39:51+00:00

Fix perf probe to return an error if no probe is added due to the given probe point being on the blacklist. To fix this problem, this moves the blacklist checking to right after finding symbols/probe-points and marks them as skipped. If all the symbols are skipped, "perf probe" returns an error as it fails to find the corresponding probe address. E.g. currently if a blacklisted probe is given: # perf probe do_trap && echo 'succeed' Added new event: Warning: Skipped probing on blacklisted function: sync_regs succeed No! It must fail! With this patch, it correctly fails: # perf probe do_trap && echo 'succeed' do_trap is blacklisted function, skip it. Probe point 'do_trap' not found. Error: Failed to add events. Signed-off-by: Masami Hiramatsu Tested-by: Arnaldo Carvalho de Melo Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Naohiro Aota Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20150616115055.19906.31359.stgit@localhost.localdomain Signed-off-by: Arnaldo Carvalho de Melo

perf probe: List probes in stdout

2015-06-16T13:34:39+00:00

Since commit 5e17b28f1e24 ("perf probe: Add --quiet option to suppress output result message") have replaced printf with pr_info, perf probe -l outputs its result in stderr. However, that is not what the commit expected. E.g.: # perf probe -l > /dev/null probe:vfs_read (on vfs_read@ksrc/linux-3/fs/read_write.c) With this fix: # perf probe -l > list # cat list probe:vfs_read (on vfs_read@ksrc/linux-3/fs/read_write.c) Of course, --quiet(-q) still works on --add/--del. # perf probe -q vfs_write # perf probe -l probe:vfs_read (on vfs_read@ksrc/linux-3/fs/read_write.c) probe:vfs_write (on vfs_write@ksrc/linux-3/fs/read_write.c) ----- Reported-by: Naohiro Aota Signed-off-by: Masami Hiramatsu Tested-by: Arnaldo Carvalho de Melo Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Naohiro Aota Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20150613013116.24402.2923.stgit@localhost.localdomain Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Cut off the gcc optimization postfixes from function name

2015-06-12T19:14:48+00:00

Cut off the postfixes which gcc added for optimized routines from the event name automatically generated from symbol name, since *probe-events doesn't accept it. Those symbols will be used if we don't use debuginfo to find target functions. E.g. without this fix; ----- # perf probe -va alloc_buf.isra.23 probe-definition(0): alloc_buf.isra.23 symbol:alloc_buf.isra.23 file:(null) line:0 offset:0 return:0 lazy:(null) [...] Opening /sys/kernel/debug/tracing/kprobe_events write=1 Added new event: Writing event: p:probe/alloc_buf.isra.23 _text+4869328 Failed to write event: Invalid argument Error: Failed to add events. Reason: Invalid argument (Code: -22) ----- With this fix; ----- perf probe -va alloc_buf.isra.23 probe-definition(0): alloc_buf.isra.23 symbol:alloc_buf.isra.23 file:(null) line:0 offset:0 return:0 lazy:(null) [...] Opening /sys/kernel/debug/tracing/kprobe_events write=1 Added new event: Writing event: p:probe/alloc_buf _text+4869328 probe:alloc_buf (on alloc_buf.isra.23) You can now use it in all perf tools, such as: perf record -e probe:alloc_buf -aR sleep 1 ----- Signed-off-by: Masami Hiramatsu Tested-by: Arnaldo Carvalho de Melo Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Naohiro Aota Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20150612050820.20548.41625.stgit@localhost.localdomain Signed-off-by: Arnaldo Carvalho de Melo

perf machine: Fix up some more method names

2015-06-08T13:31:34+00:00

Calling the function 'machine__new_module' implies a new 'module' will be allocated, when in fact what is returned is a 'struct map' instance, that not necessarily will be instantiated, as if one already exists with the given module name, it will be returned instead. So be consistent with other "find and if not there, create" like functions, like machine__findnew_thread, machine__findnew_dso, etc, and rename it to machine__findnew_module_map(), that in turn will call machine__findnew_module_dso(). Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Link: http://lkml.kernel.org/n/tip-acv830vd3hwww2ih5vjtbmu3@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Fix segfault when glob matching function without debuginfo

2015-05-30T14:08:52+00:00

Commit 4c859351226c920b227fec040a3b447f0d482af3 ("perf probe: Support glob wildcards for function name") introduces segfault problems when debuginfo is not available: # perf probe 'sys_w*' Added new events: Segmentation fault The first problem resides in find_probe_trace_events_from_map(). In that function, find_probe_functions() is called to match each symbol against glob to find the number of matching functions, but still use map__for_each_symbol_by_name() to find 'struct symbol' for matching functions. Unfortunately, map__for_each_symbol_by_name() does exact matching by searching in an rbtree. It doesn't know glob matching, and not easy for it to support it because it use rbtree based binary search, but we are unable to ensure all names matched by the glob (any glob passed by user) reside in one subtree. This patch drops map__for_each_symbol_by_name(). Since there is no rbtree again, re-matching all symbols costs a lot. This patch avoid it by saving all matching results into an array (syms). The second problem is the lost of tp->realname. In __add_probe_trace_events(), if pev->point.function is glob, the event name should be set to tev->point.realname. This patch ensures its existence by strdup sym->name instead of leaving a NULL pointer there. After this patch: # perf probe 'sys_w*' Added new events: probe:sys_waitid (on sys_w*) probe:sys_wait4 (on sys_w*) probe:sys_waitpid (on sys_w*) probe:sys_write (on sys_w*) probe:sys_writev (on sys_w*) You can now use it in all perf tools, such as: perf record -e probe:sys_writev -aR sleep 1 Signed-off-by: Wang Nan Acked-by: Masami Hiramatsu Cc: Jiri Olsa Cc: Namhyung Kim Cc: Zefan Li Link: http://lkml.kernel.org/r/1432892747-232506-1-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo

perf machine: No need to have two DSOs lists

2015-05-29T15:43:43+00:00

We can, given a DSO, figure out if it is a kernel, a kernel module or a userlevel DSO, so stop having to process two lists in several functions. If searching becomes an issue at some point, we can have them in a rbtree, etc. Cc: Adrian Hunter Cc: Borislav Petkov Cc: David Ahern Cc: Don Zickus Cc: Frederic Weisbecker Cc: Jiri Olsa Cc: Namhyung Kim Cc: Stephane Eranian Link: http://lkml.kernel.org/n/tip-s4yb0onpdywu6dj2xl9lxi4t@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Fix 'function unused' warning

2015-05-29T15:43:39+00:00

By 'make build-test' a warning is found in probe-event.c that, after commit 419e873828 (perf probe: Show the error reason comes from invalid DSO) the only user of kernel_get_module_dso() is open_debuginfo(). Which is not compiled if HAVE_DWARF_SUPPORT not set. 'make build-test' found this problem when make_minimal. This patch moves kernel_get_module_dso() to HAVE_DWARF_SUPPORT ifdef section. Signed-off-by: Wang Nan Acked-by: Masami Hiramatsu Cc: Zefan Li Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1432779905-206143-1-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo