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* tracing: Fix regression in printk_formats fileSteven Rostedt2011-06-091-4/+1
| | | | | | | | | | | | The fix to fix the printk_formats of modules broke the printk_formats of trace_printks in the kernel. The update of what to show via the seq_file was only updated if the passed in fmt was NULL, which happens only on the first iteration. The result was showing the first format every time instead of iterating through the available formats. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* ftrace: Revert 8ab2b7efd ftrace: Remove unnecessary disabling of irqsSteven Rostedt2011-06-071-0/+7
| | | | | | | | | | | | | | | | | | | Revert the commit that removed the disabling of interrupts around the initial modifying of mcount callers to nops, and update the comment. The original comment was outdated and stated that the interrupts were being disabled to prevent kstop machine, which was required with the old ftrace daemon, but was no longer the case. What the comment failed to mention was that interrupts needed to be disabled to keep interrupts from preempting the modifying of the code and then executing the code that was partially modified. Revert the commit and update the comment. Reported-by: Richard W.M. Jones <rjones@redhat.com> Tested-by: Richard W.M. Jones <rjones@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* kprobes/trace: Fix kprobe selftest for gcc 4.6Steven Rostedt2011-06-071-2/+6
| | | | | | | | | | | | | | | | With gcc 4.6, the self test kprobe function: kprobe_trace_selftest_target() is optimized such that kallsyms does not list it. The kprobes test uses this function to insert a probe and test it. But it will fail the test if the function is not listed in kallsyms. Adding a __used annotation keeps the symbol in the kallsyms table. Suggested-by: David Daney <ddaney@caviumnetworks.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* ftrace: Fix possible undefined return codeGuoWen Li2011-06-071-1/+1
| | | | | | | | | | kernel/trace/ftrace.c: In function 'ftrace_regex_write.clone.15': kernel/trace/ftrace.c:2743:6: warning: 'ret' may be used uninitialized in this function Signed-off-by: GuoWen Li <guowen.li.linux@gmail.com> Link: http://lkml.kernel.org/r/201106011918.47939.guowen.li.linux@gmail.com Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* ftrace: Add internal recursive checksSteven Rostedt2011-05-263-6/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Witold reported a reboot caused by the selftests of the dynamic function tracer. He sent me a config and I used ktest to do a config_bisect on it (as my config did not cause the crash). It pointed out that the problem config was CONFIG_PROVE_RCU. What happened was that if multiple callbacks are attached to the function tracer, we iterate a list of callbacks. Because the list is managed by synchronize_sched() and preempt_disable, the access to the pointers uses rcu_dereference_raw(). When PROVE_RCU is enabled, the rcu_dereference_raw() calls some debugging functions, which happen to be traced. The tracing of the debug function would then call rcu_dereference_raw() which would then call the debug function and then... well you get the idea. I first wrote two different patches to solve this bug. 1) add a __rcu_dereference_raw() that would not do any checks. 2) add notrace to the offending debug functions. Both of these patches worked. Talking with Paul McKenney on IRC, he suggested to add recursion detection instead. This seemed to be a better solution, so I decided to implement it. As the task_struct already has a trace_recursion to detect recursion in the ring buffer, and that has a very small number it allows, I decided to use that same variable to add flags that can detect the recursion inside the infrastructure of the function tracer. I plan to change it so that the task struct bit can be checked in mcount, but as that requires changes to all archs, I will hold that off to the next merge window. Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/1306348063.1465.116.camel@gandalf.stny.rr.com Reported-by: Witold Baryluk <baryluk@smp.if.uj.edu.pl> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Add __print_symbolic_u64 to avoid warnings on 32bit machineliubo2011-05-261-0/+27
| | | | | | | | | | Filesystem, like Btrfs, has some "ULL" macros, and when these macros are passed to tracepoints'__print_symbolic(), there will be 64->32 truncate WARNINGS during compiling on 32bit box. Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com> Link: http://lkml.kernel.org/r/4DACE6E0.7000507@cn.fujitsu.com Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* ftrace: Set ops->flag to enabled even on static function tracingSteven Rostedt2011-05-261-1/+5
| | | | | | | When dynamic ftrace is not configured, the ops->flags still needs to have its FTRACE_OPS_FL_ENABLED bit set in ftrace_startup(). Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Have event with function tracer check error returnSteven Rostedt2011-05-261-1/+6
| | | | | | | | The self tests for event tracer does not check if the function tracing was successfully activated. It needs to before it continues the tests, otherwise the wrong errors may be reported. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* ftrace: Have ftrace_startup() return failure codeSteven Rostedt2011-05-261-6/+8
| | | | | | | | | The register_ftrace_function() returns an error code on failure except if the call to ftrace_startup() fails. Add a error return to ftrace_startup() if it fails to start, allowing register_ftrace_funtion() to return a proper error value. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
*-. Merge branches 'sched-core-for-linus' and 'sched-urgent-for-linus' of ↵Linus Torvalds2011-05-201-1/+0
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (60 commits) sched: Fix and optimise calculation of the weight-inverse sched: Avoid going ahead if ->cpus_allowed is not changed sched, rt: Update rq clock when unthrottling of an otherwise idle CPU sched: Remove unused parameters from sched_fork() and wake_up_new_task() sched: Shorten the construction of the span cpu mask of sched domain sched: Wrap the 'cfs_rq->nr_spread_over' field with CONFIG_SCHED_DEBUG sched: Remove unused 'this_best_prio arg' from balance_tasks() sched: Remove noop in alloc_rt_sched_group() sched: Get rid of lock_depth sched: Remove obsolete comment from scheduler_tick() sched: Fix sched_domain iterations vs. RCU sched: Next buddy hint on sleep and preempt path sched: Make set_*_buddy() work on non-task entities sched: Remove need_migrate_task() sched: Move the second half of ttwu() to the remote cpu sched: Restructure ttwu() some more sched: Rename ttwu_post_activation() to ttwu_do_wakeup() sched: Remove rq argument from ttwu_stat() sched: Remove rq->lock from the first half of ttwu() sched: Drop rq->lock from sched_exec() ... * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: sched: Fix rt_rq runtime leakage bug
| * | Merge commit 'v2.6.39-rc7' into sched/coreIngo Molnar2011-05-123-1/+3
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| * | sched: Get rid of lock_depthJonathan Corbet2011-04-241-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Neil Brown pointed out that lock_depth somehow escaped the BKL removal work. Let's get rid of it now. Note that the perf scripting utilities still have a bunch of code for dealing with common_lock_depth in tracepoints; I have left that in place in case anybody wants to use that code with older kernels. Suggested-by: Neil Brown <neilb@suse.de> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110422111910.456c0e84@bike.lwn.net Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | ftrace: Add self-tests for multiple function trace usersSteven Rostedt2011-05-193-1/+217
| | | | | | | | | | | | | | | | | | | | | Add some basic sanity tests for multiple users of the function tracer at startup. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | | ftrace: Modify ftrace_set_filter/notrace to take opsSteven Rostedt2011-05-192-4/+46
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since users of the function tracer can now pick and choose which functions they want to trace agnostically from other users of the function tracer, we need to pass the ops struct to the ftrace_set_filter() functions. The functions ftrace_set_global_filter() and ftrace_set_global_notrace() is added to keep the old filter functions which are used to modify the generic function tracers. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | | ftrace: Allow dynamically allocated function tracersSteven Rostedt2011-05-181-7/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that functions may be selected individually, it only makes sense that we should allow dynamically allocated trace structures to be traced. This will allow perf to allocate a ftrace_ops structure at runtime and use it to pick and choose which functions that structure will trace. Note, a dynamically allocated ftrace_ops will always be called indirectly instead of being called directly from the mcount in entry.S. This is because there's no safe way to prevent mcount from being preempted before calling the function, unless we modify every entry.S to do so (not likely). Thus, dynamically allocated functions will now be called by the ftrace_ops_list_func() that loops through the ops that are allocated if there are more than one op allocated at a time. This loop is protected with a preempt_disable. To determine if an ftrace_ops structure is allocated or not, a new util function was added to the kernel/extable.c called core_kernel_data(), which returns 1 if the address is between _sdata and _edata. Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | | ftrace: Implement separate user function filteringSteven Rostedt2011-05-185-38/+160
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ftrace_ops that are registered to trace functions can now be agnostic to each other in respect to what functions they trace. Each ops has their own hash of the functions they want to trace and a hash to what they do not want to trace. A empty hash for the functions they want to trace denotes all functions should be traced that are not in the notrace hash. Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | | ftrace: Free hash with call_rcu_sched()Steven Rostedt2011-05-181-27/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | When a hash is modified and might be in use, we need to perform a schedule RCU operation on it, as the hashes will soon be used directly in the function tracer callback. Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | | ftrace: Have global_ops store the functions that are to be tracedSteven Rostedt2011-05-181-16/+53
| | | | | | | | | | | | | | | | | | | | | | | | | | | This is a step towards each ops structure defining its own set of functions to trace. As the current code with pid's and such are specific to the global_ops, it is restructured to be used with the global ops. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | | ftrace: Add ops parameter to ftrace_startup/shutdown functionsSteven Rostedt2011-05-181-14/+14
| | | | | | | | | | | | | | | | | | | | | | | | In order to allow different ops to enable different functions, the ftrace_startup() and ftrace_shutdown() functions need the ops parameter passed to them. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | | ftrace: Add enabled_functions fileSteven Rostedt2011-05-181-2/+49
| | | | | | | | | | | | | | | | | | | | | | | | | | | Add the enabled_functions file that is used to show all the functions that have been enabled for tracing as well as their ref counts. This helps seeing if any function has been registered and what functions are being traced. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | | ftrace: Use counters to enable functions to traceSteven Rostedt2011-05-181-16/+142
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Every function has its own record that stores the instruction pointer and flags for the function to be traced. There are only two flags: enabled and free. The enabled flag states that tracing for the function has been enabled (actively traced), and the free flag states that the record no longer points to a function and can be used by new functions (loaded modules). These flags are now moved to the MSB of the flags (actually just the top 32bits). The rest of the bits (30 bits) are now used as a ref counter. Everytime a tracer register functions to trace, those functions will have its counter incremented. When tracing is enabled, to determine if a function should be traced, the counter is examined, and if it is non-zero it is set to trace. When a ftrace_ops is registered to trace functions, its hashes are examined. If the ftrace_ops filter_hash count is zero, then all functions are set to be traced, otherwise only the functions in the hash are to be traced. The exception to this is if a function is also in the ftrace_ops notrace_hash. Then that function's counter is not incremented for this ftrace_ops. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | | ftrace: Separate hash allocation and assignmentSteven Rostedt2011-05-181-42/+233
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When filtering, allocate a hash to insert the function records. After the filtering is complete, assign it to the ftrace_ops structure. This allows the ftrace_ops structure to have a much smaller array of hash buckets instead of wasting a lot of memory. A read only empty_hash is created to be the minimum size that any ftrace_ops can point to. When a new hash is created, it has the following steps: o Allocate a default hash. o Walk the function records assigning the filtered records to the hash o Allocate a new hash with the appropriate size buckets o Move the entries from the default hash to the new hash. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | | ftrace: Create a global_ops to hold the filter and notrace hashesSteven Rostedt2011-05-181-19/+46
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Combine the filter and notrace hashes to be accessed by a single entity, the global_ops. The global_ops is a ftrace_ops structure that is passed to different functions that can read or modify the filtering of the function tracer. The ftrace_ops structure was modified to hold a filter and notrace hashes so that later patches may allow each ftrace_ops to have its own set of rules to what functions may be filtered. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | | ftrace: Use hash instead for FTRACE_FL_FILTERSteven Rostedt2011-05-181-82/+69
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When multiple users are allowed to have their own set of functions to trace, having the FTRACE_FL_FILTER flag will not be enough to handle the accounting of those users. Each user will need their own set of functions. Replace the FTRACE_FL_FILTER with a filter_hash instead. This is temporary until the rest of the function filtering accounting gets in. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | | ftrace: Replace FTRACE_FL_NOTRACE flag with a hash of ignored functionsSteven Rostedt2011-05-181-26/+150
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To prepare for the accounting system that will allow multiple users of the function tracer, having the FTRACE_FL_NOTRACE as a flag in the dyn_trace record does not make sense. All ftrace_ops will soon have a hash of functions they should trace and not trace. By making a global hash of functions not to trace makes this easier for the transition. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | | Merge commit 'v2.6.39-rc7' into perf/coreIngo Molnar2011-05-102-0/+2
|\ \ \ | | |/ | |/| | | | | | | | | | Merge reason: pull in the latest fixes. Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | Regression: partial revert "tracing: Remove lock_depth from event entry"Arjan van de Ven2011-05-062-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This partially reverts commit e6e1e2593592a8f6f6380496655d8c6f67431266. That commit changed the structure layout of the trace structure, which in turn broke PowerTOP (1.9x generation) quite badly. I appreciate not wanting to expose the variable in question, and PowerTOP was not using it, so I've replaced the variable with just a padding field - that way if in the future a new field is needed it can just use this padding field. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | Merge branch 'tip/perf/core' of ↵Ingo Molnar2011-05-011-209/+138
|\ \ \ | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/core
| * | | ftrace: Consolidate the function match routines for normal and modsSteven Rostedt2011-04-301-62/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The code used for matching functions is almost identical between normal selecting of functions and using the :mod: feature of set_ftrace_notrace. Consolidate the two users into one function. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | | ftrace: Consolidate updating of ftrace_trace_functionSteven Rostedt2011-04-301-61/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are three locations that perform almost identical functions in order to update the ftrace_trace_function (the ftrace function variable that gets called by mcount). Consolidate these into a single function called update_ftrace_function(). Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | | ftrace: Move record update for normal and modules into a separate functionSteven Rostedt2011-04-301-8/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The updating of a function record is moved to a single function. This will allow us to add specific changes in one location for both modules and kernel functions. Later patches will determine if the function record itself needs to be updated (which enables the mcount caller), or just the ftrace_ops needs the update. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | | ftrace: Remove FTRACE_FL_CONVERTED flagSteven Rostedt2011-04-301-8/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since we disable all function tracer processing if we detect that a modification of a instruction had failed, we do not need to track that the record has failed. No more ftrace processing is allowed, and the FTRACE_FL_CONVERTED flag is pointless. The FTRACE_FL_CONVERTED flag was used to denote records that were successfully converted from mcount calls into nops. But if a single record fails, all of ftrace is disabled. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | | ftrace: Remove FTRACE_FL_FAILED flagSteven Rostedt2011-04-301-29/+47
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since we disable all function tracer processing if we detect that a modification of a instruction had failed, we do not need to track that the record has failed. No more ftrace processing is allowed, and the FTRACE_FL_FAILED flag is pointless. Removing this flag simplifies some of the code, but some ftrace_disabled checks needed to be added or move around a little. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | | ftrace: Remove failures fileSteven Rostedt2011-04-301-37/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The failures file in the debugfs tracing directory would list the functions that failed to convert when the old dead ftrace daemon tried to update code but failed. Since this code is now dead along with the daemon the failures file is useless. Remove it. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | | ftrace: Remove unnecessary disabling of irqsSteven Rostedt2011-04-301-4/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The disabling of interrupts around ftrace_update_code() was used to protect against the evil ftrace daemon from years past. But that daemon has long been killed. It is safe to keep interrupts enabled while updating the initial mcount into nops. The ftrace_mutex is also held which keeps other users at bay. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | | ftrace: Make FTRACE_WARN_ON() work in if conditionSteven Rostedt2011-04-301-6/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Let FTRACE_WARN_ON() be used as a stand alone statement or inside a conditional: if (FTRACE_WARN_ON(x)) Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | | | Merge branch 'tip/perf/urgent' of ↵Ingo Molnar2011-05-012-6/+8
|\ \ \ \ | |/ / / |/| | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/core
| * | | ftrace: Only update the function code on write to filter filesSteven Rostedt2011-04-301-5/+7
| |/ / | | | | | | | | | | | | | | | | | | | | | | | | If function tracing is enabled, a read of the filter files will cause the call to stop_machine to update the function trace sites. It should only call stop_machine on write. Cc: stable@kernel.org Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | Merge branch 'tip/perf/urgent' of ↵Ingo Molnar2011-04-271-1/+1
| |\ \ | | |/ | |/| | | | git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/urgent
| | * ftrace: Build without frame pointers on MicroblazeMichal Simek2011-04-211-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Microblaze doesn't need/support FRAME_POINTERS in order to have a working function tracer. The patch remove Kconfig warning. Warning log: warning: (LOCKDEP && FAULT_INJECTION_STACKTRACE_FILTER && LATENCYTOP && FUNCTION_TRACER && KMEMCHECK) selects FRAME_POINTER which has unmet direct dependencies (DEBUG_KERNEL && (CRIS || M68K || FRV || UML || AVR32 || SUPERH || BLACKFIN || MN10300) || ARCH_WANT_FRAME_POINTERS) Signed-off-by: Michal Simek <monstr@monstr.eu> Link: http://lkml.kernel.org/r/1301908812-8119-2-git-send-email-monstr@monstr.eu CC: Frederic Weisbecker <fweisbec@gmail.com> CC: Ingo Molnar <mingo@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | | Merge branch 'tip/perf/core' of ↵Ingo Molnar2011-04-273-15/+123
|\ \ \ | |/ / |/| | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/core Conflicts: include/linux/perf_event.h Merge reason: pick up the latest jump-label enhancements, they are cooked ready. Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | tracing: Avoid soft lockup in trace_pipeJiri Olsa2011-04-042-3/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | running following commands: # enable the binary option echo 1 > ./options/bin # disable context info option echo 0 > ./options/context-info # tracing only events echo 1 > ./events/enable cat trace_pipe plus forcing system to generate many tracing events, is causing lockup (in NON preemptive kernels) inside tracing_read_pipe function. The issue is also easily reproduced by running ltp stress test. (ftrace_stress_test.sh) The reasons are: - bin/hex/raw output functions for events are set to trace_nop_print function, which prints nothing and returns TRACE_TYPE_HANDLED value - LOST EVENT trace do not handle trace_seq overflow These reasons force the while loop in tracing_read_pipe function never to break. The attached patch fixies handling of lost event trace, and changes trace_nop_print to print minimal info, which is needed for the correct tracing_read_pipe processing. v2 changes: - omit the cond_resched changes by trace_nop_print changes - WARN changed to WARN_ONCE and added info to be able to find out the culprit v3 changes: - make more accurate patch comment Signed-off-by: Jiri Olsa <jolsa@redhat.com> LKML-Reference: <20110325110518.GC1922@jolsa.brq.redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | tracing: Print trace_bprintk() formats for modules tooSteven Rostedt2011-04-041-6/+97
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The file debugfs/tracing/printk_formats maps the addresses to the formats that are used by trace_bprintk() so that userspace tools can read the buffer and be able to decode trace_bprintk events to get the format saved when reading the ring buffer directly. This is because trace_bprintk() does not store the format into the buffer, but just the address of the format, which is hidden in the kernel memory. But currently it only exports trace_bprintk()s from the kernel core and not for modules. The modules need their formats exported as well. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | tracing: Convert trace_printk() formats for module to const char *Steven Rostedt2011-04-041-6/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The trace_printk() formats for modules do not show up in the debugfs/tracing/printk_formats file. Only the formats that are for trace_printk()s that are in the kernel core. To facilitate the change to add trace_printk() formats from modules into that file as well, we need to convert the structure that holds the formats from char fmt[], into const char *fmt, and allocate them separately. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | | block: make unplug timer trace event correspond to the schedule() unplugJens Axboe2011-04-161-6/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It's a pretty close match to what we had before - the timer triggering would mean that nobody unplugged the plug in due time, in the new scheme this matches very closely what the schedule() unplug now is. It's essentially the difference between an explicit unplug (IO unplug) or an implicit unplug (timer unplug, we scheduled with pending IO queued). Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
* | | block: fixup block IO unplug trace callJens Axboe2011-04-121-3/+3
| | | | | | | | | | | | | | | | | | | | | It was removed with the on-stack plugging, readd it and track the depth of requests added when flushing the plug. Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
* | | block: remove block_unplug_timer() trace pointJens Axboe2011-04-121-17/+0
| |/ |/| | | | | | | | | | | We no longer have an unplug timer running, so no point in keeping the trace point. Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
* | Fix common misspellingsLucas De Marchi2011-03-318-10/+10
|/ | | | | | Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
* Merge branch 'perf-fixes-for-linus' of ↵Linus Torvalds2011-03-261-2/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: perf, x86: Complain louder about BIOSen corrupting CPU/PMU state and continue perf, x86: P4 PMU - Read proper MSR register to catch unflagged overflows perf symbols: Look at .dynsym again if .symtab not found perf build-id: Add quirk to deal with perf.data file format breakage perf session: Pass evsel in event_ops->sample() perf: Better fit max unprivileged mlock pages for tools needs perf_events: Fix stale ->cgrp pointer in update_cgrp_time_from_cpuctx() perf top: Fix uninitialized 'counter' variable tracing: Fix set_ftrace_filter probe function display perf, x86: Fix Intel fixed counters base initialization
| * Merge branch 'tip/perf/urgent' of ↵Ingo Molnar2011-03-231-2/+1
| |\ | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/urgent