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author | Linus Torvalds <torvalds@linux-foundation.org> | 2012-10-01 10:28:49 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-10-01 10:28:49 -0700 |
commit | 7e92daaefa68e5ef1e1732e45231e73adbb724e7 (patch) | |
tree | 8e7f8ac9d82654df4c65939c6682f95510e22977 /kernel/trace/trace_selftest.c | |
parent | 7a68294278ae714ce2632a54f0f46916dca64f56 (diff) | |
parent | 1d787d37c8ff6612b8151c6dff15bfa7347bcbdf (diff) | |
download | lwn-7e92daaefa68e5ef1e1732e45231e73adbb724e7.tar.gz lwn-7e92daaefa68e5ef1e1732e45231e73adbb724e7.zip |
Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf update from Ingo Molnar:
"Lots of changes in this cycle as well, with hundreds of commits from
over 30 contributors. Most of the activity was on the tooling side.
Higher level changes:
- New 'perf kvm' analysis tool, from Xiao Guangrong.
- New 'perf trace' system-wide tracing tool
- uprobes fixes + cleanups from Oleg Nesterov.
- Lots of patches to make perf build on Android out of box, from
Irina Tirdea
- Extend ftrace function tracing utility to be more dynamic for its
users. It allows for data passing to the callback functions, as
well as reading regs as if a breakpoint were to trigger at function
entry.
The main goal of this patch series was to allow kprobes to use
ftrace as an optimized probe point when a probe is placed on an
ftrace nop. With lots of help from Masami Hiramatsu, and going
through lots of iterations, we finally came up with a good
solution.
- Add cpumask for uncore pmu, use it in 'stat', from Yan, Zheng.
- Various tracing updates from Steve Rostedt
- Clean up and improve 'perf sched' performance by elliminating lots
of needless calls to libtraceevent.
- Event group parsing support, from Jiri Olsa
- UI/gtk refactorings and improvements from Namhyung Kim
- Add support for non-tracepoint events in perf script python, from
Feng Tang
- Add --symbols to 'script', similar to the one in 'report', from
Feng Tang.
Infrastructure enhancements and fixes:
- Convert the trace builtins to use the growing evsel/evlist
tracepoint infrastructure, removing several open coded constructs
like switch like series of strcmp to dispatch events, etc.
Basically what had already been showcased in 'perf sched'.
- Add evsel constructor for tracepoints, that uses libtraceevent just
to parse the /format events file, use it in a new 'perf test' to
make sure the libtraceevent format parsing regressions can be more
readily caught.
- Some strange errors were happening in some builds, but not on the
next, reported by several people, problem was some parser related
files, generated during the build, didn't had proper make deps, fix
from Eric Sandeen.
- Introduce struct and cache information about the environment where
a perf.data file was captured, from Namhyung Kim.
- Fix handling of unresolved samples when --symbols is used in
'report', from Feng Tang.
- Add union member access support to 'probe', from Hyeoncheol Lee.
- Fixups to die() removal, from Namhyung Kim.
- Render fixes for the TUI, from Namhyung Kim.
- Don't enable annotation in non symbolic view, from Namhyung Kim.
- Fix pipe mode in 'report', from Namhyung Kim.
- Move related stats code from stat to util/, will be used by the
'stat' kvm tool, from Xiao Guangrong.
- Remove die()/exit() calls from several tools.
- Resolve vdso callchains, from Jiri Olsa
- Don't pass const char pointers to basename, so that we can
unconditionally use libgen.h and thus avoid ifdef BIONIC lines,
from David Ahern
- Refactor hist formatting so that it can be reused with the GTK
browser, From Namhyung Kim
- Fix build for another rbtree.c change, from Adrian Hunter.
- Make 'perf diff' command work with evsel hists, from Jiri Olsa.
- Use the only field_sep var that is set up: symbol_conf.field_sep,
fix from Jiri Olsa.
- .gitignore compiled python binaries, from Namhyung Kim.
- Get rid of die() in more libtraceevent places, from Namhyung Kim.
- Rename libtraceevent 'private' struct member to 'priv' so that it
works in C++, from Steven Rostedt
- Remove lots of exit()/die() calls from tools so that the main perf
exit routine can take place, from David Ahern
- Fix x86 build on x86-64, from David Ahern.
- {int,str,rb}list fixes from Suzuki K Poulose
- perf.data header fixes from Namhyung Kim
- Allow user to indicate objdump path, needed in cross environments,
from Maciek Borzecki
- Fix hardware cache event name generation, fix from Jiri Olsa
- Add round trip test for sw, hw and cache event names, catching the
problem Jiri fixed, after Jiri's patch, the test passes
successfully.
- Clean target should do clean for lib/traceevent too, fix from David
Ahern
- Check the right variable for allocation failure, fix from Namhyung
Kim
- Set up evsel->tp_format regardless of evsel->name being set
already, fix from Namhyung Kim
- Oprofile fixes from Robert Richter.
- Remove perf_event_attr needless version inflation, from Jiri Olsa
- Introduce libtraceevent strerror like error reporting facility,
from Namhyung Kim
- Add pmu mappings to perf.data header and use event names from cmd
line, from Robert Richter
- Fix include order for bison/flex-generated C files, from Ben
Hutchings
- Build fixes and documentation corrections from David Ahern
- Assorted cleanups from Robert Richter
- Let O= makes handle relative paths, from Steven Rostedt
- perf script python fixes, from Feng Tang.
- Initial bash completion support, from Frederic Weisbecker
- Allow building without libelf, from Namhyung Kim.
- Support DWARF CFI based unwind to have callchains when %bp based
unwinding is not possible, from Jiri Olsa.
- Symbol resolution fixes, while fixing support PPC64 files with an
.opt ELF section was the end goal, several fixes for code that
handles all architectures and cleanups are included, from Cody
Schafer.
- Assorted fixes for Documentation and build in 32 bit, from Robert
Richter
- Cache the libtraceevent event_format associated to each evsel
early, so that we avoid relookups, i.e. calling pevent_find_event
repeatedly when processing tracepoint events.
[ This is to reduce the surface contact with libtraceevents and
make clear what is that the perf tools needs from that lib: so
far parsing the common and per event fields. ]
- Don't stop the build if the audit libraries are not installed, fix
from Namhyung Kim.
- Fix bfd.h/libbfd detection with recent binutils, from Markus
Trippelsdorf.
- Improve warning message when libunwind devel packages not present,
from Jiri Olsa"
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (282 commits)
perf trace: Add aliases for some syscalls
perf probe: Print an enum type variable in "enum variable-name" format when showing accessible variables
perf tools: Check libaudit availability for perf-trace builtin
perf hists: Add missing period_* fields when collapsing a hist entry
perf trace: New tool
perf evsel: Export the event_format constructor
perf evsel: Introduce rawptr() method
perf tools: Use perf_evsel__newtp in the event parser
perf evsel: The tracepoint constructor should store sys:name
perf evlist: Introduce set_filter() method
perf evlist: Renane set_filters method to apply_filters
perf test: Add test to check we correctly parse and match syscall open parms
perf evsel: Handle endianity in intval method
perf evsel: Know if byte swap is needed
perf tools: Allow handling a NULL cpu_map as meaning "all cpus"
perf evsel: Improve tracepoint constructor setup
tools lib traceevent: Fix error path on pevent_parse_event
perf test: Fix build failure
trace: Move trace event enable from fs_initcall to core_initcall
tracing: Add an option for disabling markers
...
Diffstat (limited to 'kernel/trace/trace_selftest.c')
-rw-r--r-- | kernel/trace/trace_selftest.c | 304 |
1 files changed, 283 insertions, 21 deletions
diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c index 288541f977fb..2c00a691a540 100644 --- a/kernel/trace/trace_selftest.c +++ b/kernel/trace/trace_selftest.c @@ -103,54 +103,67 @@ static inline void warn_failed_init_tracer(struct tracer *trace, int init_ret) static int trace_selftest_test_probe1_cnt; static void trace_selftest_test_probe1_func(unsigned long ip, - unsigned long pip) + unsigned long pip, + struct ftrace_ops *op, + struct pt_regs *pt_regs) { trace_selftest_test_probe1_cnt++; } static int trace_selftest_test_probe2_cnt; static void trace_selftest_test_probe2_func(unsigned long ip, - unsigned long pip) + unsigned long pip, + struct ftrace_ops *op, + struct pt_regs *pt_regs) { trace_selftest_test_probe2_cnt++; } static int trace_selftest_test_probe3_cnt; static void trace_selftest_test_probe3_func(unsigned long ip, - unsigned long pip) + unsigned long pip, + struct ftrace_ops *op, + struct pt_regs *pt_regs) { trace_selftest_test_probe3_cnt++; } static int trace_selftest_test_global_cnt; static void trace_selftest_test_global_func(unsigned long ip, - unsigned long pip) + unsigned long pip, + struct ftrace_ops *op, + struct pt_regs *pt_regs) { trace_selftest_test_global_cnt++; } static int trace_selftest_test_dyn_cnt; static void trace_selftest_test_dyn_func(unsigned long ip, - unsigned long pip) + unsigned long pip, + struct ftrace_ops *op, + struct pt_regs *pt_regs) { trace_selftest_test_dyn_cnt++; } static struct ftrace_ops test_probe1 = { .func = trace_selftest_test_probe1_func, + .flags = FTRACE_OPS_FL_RECURSION_SAFE, }; static struct ftrace_ops test_probe2 = { .func = trace_selftest_test_probe2_func, + .flags = FTRACE_OPS_FL_RECURSION_SAFE, }; static struct ftrace_ops test_probe3 = { .func = trace_selftest_test_probe3_func, + .flags = FTRACE_OPS_FL_RECURSION_SAFE, }; static struct ftrace_ops test_global = { - .func = trace_selftest_test_global_func, - .flags = FTRACE_OPS_FL_GLOBAL, + .func = trace_selftest_test_global_func, + .flags = FTRACE_OPS_FL_GLOBAL | FTRACE_OPS_FL_RECURSION_SAFE, }; static void print_counts(void) @@ -393,10 +406,253 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace, return ret; } + +static int trace_selftest_recursion_cnt; +static void trace_selftest_test_recursion_func(unsigned long ip, + unsigned long pip, + struct ftrace_ops *op, + struct pt_regs *pt_regs) +{ + /* + * This function is registered without the recursion safe flag. + * The ftrace infrastructure should provide the recursion + * protection. If not, this will crash the kernel! + */ + trace_selftest_recursion_cnt++; + DYN_FTRACE_TEST_NAME(); +} + +static void trace_selftest_test_recursion_safe_func(unsigned long ip, + unsigned long pip, + struct ftrace_ops *op, + struct pt_regs *pt_regs) +{ + /* + * We said we would provide our own recursion. By calling + * this function again, we should recurse back into this function + * and count again. But this only happens if the arch supports + * all of ftrace features and nothing else is using the function + * tracing utility. + */ + if (trace_selftest_recursion_cnt++) + return; + DYN_FTRACE_TEST_NAME(); +} + +static struct ftrace_ops test_rec_probe = { + .func = trace_selftest_test_recursion_func, +}; + +static struct ftrace_ops test_recsafe_probe = { + .func = trace_selftest_test_recursion_safe_func, + .flags = FTRACE_OPS_FL_RECURSION_SAFE, +}; + +static int +trace_selftest_function_recursion(void) +{ + int save_ftrace_enabled = ftrace_enabled; + int save_tracer_enabled = tracer_enabled; + char *func_name; + int len; + int ret; + int cnt; + + /* The previous test PASSED */ + pr_cont("PASSED\n"); + pr_info("Testing ftrace recursion: "); + + + /* enable tracing, and record the filter function */ + ftrace_enabled = 1; + tracer_enabled = 1; + + /* Handle PPC64 '.' name */ + func_name = "*" __stringify(DYN_FTRACE_TEST_NAME); + len = strlen(func_name); + + ret = ftrace_set_filter(&test_rec_probe, func_name, len, 1); + if (ret) { + pr_cont("*Could not set filter* "); + goto out; + } + + ret = register_ftrace_function(&test_rec_probe); + if (ret) { + pr_cont("*could not register callback* "); + goto out; + } + + DYN_FTRACE_TEST_NAME(); + + unregister_ftrace_function(&test_rec_probe); + + ret = -1; + if (trace_selftest_recursion_cnt != 1) { + pr_cont("*callback not called once (%d)* ", + trace_selftest_recursion_cnt); + goto out; + } + + trace_selftest_recursion_cnt = 1; + + pr_cont("PASSED\n"); + pr_info("Testing ftrace recursion safe: "); + + ret = ftrace_set_filter(&test_recsafe_probe, func_name, len, 1); + if (ret) { + pr_cont("*Could not set filter* "); + goto out; + } + + ret = register_ftrace_function(&test_recsafe_probe); + if (ret) { + pr_cont("*could not register callback* "); + goto out; + } + + DYN_FTRACE_TEST_NAME(); + + unregister_ftrace_function(&test_recsafe_probe); + + /* + * If arch supports all ftrace features, and no other task + * was on the list, we should be fine. + */ + if (!ftrace_nr_registered_ops() && !FTRACE_FORCE_LIST_FUNC) + cnt = 2; /* Should have recursed */ + else + cnt = 1; + + ret = -1; + if (trace_selftest_recursion_cnt != cnt) { + pr_cont("*callback not called expected %d times (%d)* ", + cnt, trace_selftest_recursion_cnt); + goto out; + } + + ret = 0; +out: + ftrace_enabled = save_ftrace_enabled; + tracer_enabled = save_tracer_enabled; + + return ret; +} #else # define trace_selftest_startup_dynamic_tracing(trace, tr, func) ({ 0; }) +# define trace_selftest_function_recursion() ({ 0; }) #endif /* CONFIG_DYNAMIC_FTRACE */ +static enum { + TRACE_SELFTEST_REGS_START, + TRACE_SELFTEST_REGS_FOUND, + TRACE_SELFTEST_REGS_NOT_FOUND, +} trace_selftest_regs_stat; + +static void trace_selftest_test_regs_func(unsigned long ip, + unsigned long pip, + struct ftrace_ops *op, + struct pt_regs *pt_regs) +{ + if (pt_regs) + trace_selftest_regs_stat = TRACE_SELFTEST_REGS_FOUND; + else + trace_selftest_regs_stat = TRACE_SELFTEST_REGS_NOT_FOUND; +} + +static struct ftrace_ops test_regs_probe = { + .func = trace_selftest_test_regs_func, + .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_SAVE_REGS, +}; + +static int +trace_selftest_function_regs(void) +{ + int save_ftrace_enabled = ftrace_enabled; + int save_tracer_enabled = tracer_enabled; + char *func_name; + int len; + int ret; + int supported = 0; + +#ifdef ARCH_SUPPORTS_FTRACE_SAVE_REGS + supported = 1; +#endif + + /* The previous test PASSED */ + pr_cont("PASSED\n"); + pr_info("Testing ftrace regs%s: ", + !supported ? "(no arch support)" : ""); + + /* enable tracing, and record the filter function */ + ftrace_enabled = 1; + tracer_enabled = 1; + + /* Handle PPC64 '.' name */ + func_name = "*" __stringify(DYN_FTRACE_TEST_NAME); + len = strlen(func_name); + + ret = ftrace_set_filter(&test_regs_probe, func_name, len, 1); + /* + * If DYNAMIC_FTRACE is not set, then we just trace all functions. + * This test really doesn't care. + */ + if (ret && ret != -ENODEV) { + pr_cont("*Could not set filter* "); + goto out; + } + + ret = register_ftrace_function(&test_regs_probe); + /* + * Now if the arch does not support passing regs, then this should + * have failed. + */ + if (!supported) { + if (!ret) { + pr_cont("*registered save-regs without arch support* "); + goto out; + } + test_regs_probe.flags |= FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED; + ret = register_ftrace_function(&test_regs_probe); + } + if (ret) { + pr_cont("*could not register callback* "); + goto out; + } + + + DYN_FTRACE_TEST_NAME(); + + unregister_ftrace_function(&test_regs_probe); + + ret = -1; + + switch (trace_selftest_regs_stat) { + case TRACE_SELFTEST_REGS_START: + pr_cont("*callback never called* "); + goto out; + + case TRACE_SELFTEST_REGS_FOUND: + if (supported) + break; + pr_cont("*callback received regs without arch support* "); + goto out; + + case TRACE_SELFTEST_REGS_NOT_FOUND: + if (!supported) + break; + pr_cont("*callback received NULL regs* "); + goto out; + } + + ret = 0; +out: + ftrace_enabled = save_ftrace_enabled; + tracer_enabled = save_tracer_enabled; + + return ret; +} + /* * Simple verification test of ftrace function tracer. * Enable ftrace, sleep 1/10 second, and then read the trace @@ -442,7 +698,14 @@ trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr) ret = trace_selftest_startup_dynamic_tracing(trace, tr, DYN_FTRACE_TEST_NAME); + if (ret) + goto out; + ret = trace_selftest_function_recursion(); + if (ret) + goto out; + + ret = trace_selftest_function_regs(); out: ftrace_enabled = save_ftrace_enabled; tracer_enabled = save_tracer_enabled; @@ -778,6 +1041,8 @@ static int trace_wakeup_test_thread(void *data) set_current_state(TASK_INTERRUPTIBLE); schedule(); + complete(x); + /* we are awake, now wait to disappear */ while (!kthread_should_stop()) { /* @@ -821,24 +1086,21 @@ trace_selftest_startup_wakeup(struct tracer *trace, struct trace_array *tr) /* reset the max latency */ tracing_max_latency = 0; - /* sleep to let the RT thread sleep too */ - msleep(100); + while (p->on_rq) { + /* + * Sleep to make sure the RT thread is asleep too. + * On virtual machines we can't rely on timings, + * but we want to make sure this test still works. + */ + msleep(100); + } - /* - * Yes this is slightly racy. It is possible that for some - * strange reason that the RT thread we created, did not - * call schedule for 100ms after doing the completion, - * and we do a wakeup on a task that already is awake. - * But that is extremely unlikely, and the worst thing that - * happens in such a case, is that we disable tracing. - * Honestly, if this race does happen something is horrible - * wrong with the system. - */ + init_completion(&isrt); wake_up_process(p); - /* give a little time to let the thread wake up */ - msleep(100); + /* Wait for the task to wake up */ + wait_for_completion(&isrt); /* stop the tracing. */ tracing_stop(); |