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* ftrace: powerpc clean upsSteven Rostedt2008-05-266-20/+20
| | | | | | | | | | | | | | | | This patch cleans up the ftrace code in PowerPC based on the comments from Michael Ellerman. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Cc: Michael Ellerman <michael@ellerman.id.au> Cc: proski@gnu.org Cc: a.p.zijlstra@chello.nl Cc: Pekka Paalanen <pq@iki.fi> Cc: Steven Rostedt <srostedt@redhat.com> Cc: linuxppc-dev@ozlabs.org Cc: Soeren Sandmann Pedersen <sandmann@redhat.com> Cc: paulus@samba.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* ftrace: fix up cmdline recordingSteven Rostedt2008-05-264-13/+19
| | | | | | | | | | The new work with converting the trace hooks over to markers broke the command line recording of ftrace. This patch fixes it again. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* ftrace: set_ftrace_notrace featureSteven Rostedt2008-05-262-40/+131
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While debugging latencies in the RT kernel, I found that it would be nice to be able to filter away functions from the trace than just to filter on functions. I added a new interface to the debugfs tracing directory called set_ftrace_notrace When dynamic frace is enabled, this lets you filter away functions that will not be recorded in the trace. It is similar to adding 'notrace' to those functions but by doing it without recompiling the kernel. Here's how set_ftrace_filter and set_ftrace_notrace interact. Remember, if set_ftrace_filter is set, it removes all functions from the trace execpt for those listed in the set_ftrace_filter. set_ftrace_notrace will prevent those functions from being traced. If you were to set one function in both set_ftrace_filter and set_ftrace_notrace and that function was the same, then you would end up with an empty trace. the set of functions to trace is: set_ftrace_filter == empty then all functions not in set_ftrace_notrace else set of the set_ftrace_filter and not in set of set_ftrace_notrace. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* ftrace: remove printks from irqsoff traceSteven Rostedt2008-05-261-16/+0
| | | | | | | | | | | | | | | | | Printing out new max latencies was fine for the old RT tracer. But for mainline it is a bit messy. We also need to test if the run queue is locked before we can do the print. This means that we may not be printing out latencies if the run queue is locked on another CPU. This produces inconsistencies in the output. This patch simply removes the print altogether. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Cc: pq@iki.fi Cc: proski@gnu.org Cc: sandmann@redhat.com Cc: a.p.zijlstra@chello.nl Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* ftrace: add function tracing to wake up tracingSteven Rostedt2008-05-261-1/+66
| | | | | | | | | | | | This patch adds function tracing to the functions that are called on the CPU of the task being traced. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Cc: pq@iki.fi Cc: proski@gnu.org Cc: sandmann@redhat.com Cc: a.p.zijlstra@chello.nl Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* ftrace: move ftrace_special to trace.cSteven Rostedt2008-05-262-26/+25
| | | | | | | | | | | Move the ftrace_special out of sched_switch to trace.c. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Cc: pq@iki.fi Cc: proski@gnu.org Cc: sandmann@redhat.com Cc: a.p.zijlstra@chello.nl Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* ftrace: limit use of check pagesSteven Rostedt2008-05-262-9/+24
| | | | | | | | | | | | | | | | | | | | The check_pages function is called often enough that it can cause problems with trace outputs or even bringing the system to a halt. This patch limits the check_pages to the places that are most likely to have problems. The check is made at the flip between the global array and the max save array, as well as when the size of the buffers changes and the self tests. This patch also removes the BUG_ON from check_pages and replaces it with a WARN_ON and disabling of the tracer. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Cc: pq@iki.fi Cc: proski@gnu.org Cc: sandmann@redhat.com Cc: a.p.zijlstra@chello.nl Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* sched: do not trace sched_clockIngo Molnar2008-05-251-3/+3
| | | | | | | The tracer uses sched_clock, so do not trace it. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* ftrace: add have dynamic ftrace config for archsSteven Rostedt2008-05-234-0/+7
| | | | | | | | | | | | | | Now that ftrace is being ported to other architectures, it has become apparent that DYNAMIC_FTRACE is dependent on whether or not that architecture implements dynamic ftrace. FTRACE itself may be ported to an architecture without porting dynamic ftrace. This patch adds HAVE_DYNAMIC_FTRACE to allow architectures to port ftrace without having to also port the dynamic aspect as well. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* ftrace: use the new kbuild CFLAGS_REMOVE for x86/kernel directorySteven Rostedt2008-05-231-0/+7
| | | | | | | | | This patch removes the Makefile turd and uses the nice CFLAGS_REMOVE macro in the x86/kernel directory. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* ftrace: use the new kbuild CFLAGS_REMOVE for lib directorySteven Rostedt2008-05-231-4/+4
| | | | | | | | | This patch removes the Makefile turd and uses the nice CFLAGS_REMOVE macro in the lib directory. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* ftrace: use the new kbuild CFLAGS_REMOVE for kernel directorySteven Rostedt2008-05-231-5/+9
| | | | | | | | | This patch removes the Makefile turd and uses the nice CFLAGS_REMOVE macro in the kernel directory. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* kbuild: create new CFLAGS_REMOVE_(basename).o optionSteven Rostedt2008-05-231-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | We currently have a way to add special CFLAGS to code, but we do not have a way to remove them if needed. With the case of ftrace, some files should simply not be profiled. Adding the -pg flag to these files is simply a waste, and adding "notrace" to each and every function is ugly. Currently we put in "Makefile turd" [1] to stop the compiler from adding -pg to certain files. This was clumsy and awkward. This patch now adds the revese of CFLAGS_(basename).o with CFLAGS_REMOVE_(basename).o. This allows developers to prevent certain CFLAGS from being used to compile files. For example, we can now do CFLAGS_REMOVE_string.o = -pg to remove the -pg option from the string.o file in the lib directory. Note: a space delimited list of options may be added to the REMOVE macro. [1] - what David Miller called the workaronud to remove -pg Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* ftrace: support for PowerPCSteven Rostedt2008-05-2311-10/+405
| | | | | | | | | This patch adds full support for ftrace for PowerPC (both 64 and 32 bit). This includes dynamic tracing and function filtering. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* ftrace, POWERPC: add irqs_disabled_flags to ppcSteven Rostedt2008-05-231-0/+10
| | | | | | | | | PPC doesn't have the irqs_disabled_flags needed by ftrace. This patch adds it. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* ftrace: fix build bugIngo Molnar2008-05-231-4/+4
| | | | | Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* ftrace: fix include file dependencyIngo Molnar2008-05-231-0/+1
| | | | | Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* ftrace: cleanupsIngo Molnar2008-05-231-3/+3
| | | | | | | factor out code and clean it up. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* ftrace: fix mcount export bugIngo Molnar2008-05-233-6/+17
| | | | | | | | | | David S. Miller noticed the following bug: the -pg instrumentation function callback is named differently on each platform. On x86 it is mcount, on sparc it is _mcount. So the export does not make sense in kernel/trace/ftrace.c - move it to x86. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* sparc64: add ftrace support.David Miller2008-05-235-5/+156
| | | | | | Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* ftrace: remove packed attribute on ftrace_page.David Miller2008-05-231-2/+2
| | | | | | | | | | | | | | | | It causes unaligned access traps on platforms like sparc (ftrace_page may be marked packed, but once we return a dyn_ftrace sub-object from this array to another piece of code, the "packed" part of the typing information doesn't propagate). But also, it didn't serve any purpose either. Even if packed, on 64-bit or 32-bit, it didn't give us any more dyn_ftrace entries per-page. Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* ftrace: stacktrace fixIngo Molnar2008-05-234-3/+13
| | | | | Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* Port ftrace to markersMathieu Desnoyers2008-05-235-88/+255
| | | | | | | | | | | | Porting ftrace to the marker infrastructure. Don't need to chain to the wakeup tracer from the sched tracer, because markers support multiple probes connected. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> CC: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* Markers - define non optimized markerMathieu Desnoyers2008-05-231-5/+24
| | | | | | | | | | | | | | To support the forthcoming "immediate values" marker optimization, we must have a way to declare markers in few code paths that does not use instruction modification based enable. This will be the case of printk(), some traps and eventually lockdep instrumentation. Changelog : - Fix reversed boolean logic of "generic". Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* Markers - remove extra format argumentMathieu Desnoyers2008-05-232-22/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Denys Vlasenko <vda.linux@googlemail.com> : > Not in this patch, but I noticed: > > #define __trace_mark(name, call_private, format, args...) \ > do { \ > static const char __mstrtab_##name[] \ > __attribute__((section("__markers_strings"))) \ > = #name "\0" format; \ > static struct marker __mark_##name \ > __attribute__((section("__markers"), aligned(8))) = \ > { __mstrtab_##name, &__mstrtab_##name[sizeof(#name)], \ > 0, 0, marker_probe_cb, \ > { __mark_empty_function, NULL}, NULL }; \ > __mark_check_format(format, ## args); \ > if (unlikely(__mark_##name.state)) { \ > (*__mark_##name.call) \ > (&__mark_##name, call_private, \ > format, ## args); \ > } \ > } while (0) > > In this call: > > (*__mark_##name.call) \ > (&__mark_##name, call_private, \ > format, ## args); \ > > you make gcc allocate duplicate format string. You can use > &__mstrtab_##name[sizeof(#name)] instead since it holds the same string, > or drop ", format," above and "const char *fmt" from here: > > void (*call)(const struct marker *mdata, /* Probe wrapper */ > void *call_private, const char *fmt, ...); > > since mdata->format is the same and all callees which need it can take it there. Very good point. I actually thought about dropping it, since it would remove an unnecessary argument from the stack. And actually, since I now have the marker_probe_cb sitting between the marker site and the callbacks, there is no API change required. Thanks :) Mathieu Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> CC: Denys Vlasenko <vda.linux@googlemail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* ftrace: limit trace entriesSteven Rostedt2008-05-233-3/+47
| | | | | | | | | | | | | | | | | | | | | | Currently there is no protection from the root user to use up all of memory for trace buffers. If the root user allocates too many entries, the OOM killer might start kill off all tasks. This patch adds an algorith to check the following condition: pages_requested > (freeable_memory + current_trace_buffer_pages) / 4 If the above is met then the allocation fails. The above prevents more than 1/4th of freeable memory from being used by trace buffers. To determine the freeable_memory, I made determine_dirtyable_memory in mm/page-writeback.c global. Special thanks goes to Peter Zijlstra for suggesting the above calculation. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* ftrace: add readpos to struct trace_seq; add trace_seq_to_user()Pekka Paalanen2008-05-232-37/+39
| | | | | | | | | | Refactor code from tracing_read_pipe() and create trace_seq_to_user(). Moved trace_seq_reset() call before iter->trace->read() call so that when all leftover data is returned, trace_seq is reset automatically. Signed-off-by: Pekka Paalanen <pq@iki.fi> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* ftrace: use raw_smp_processor_id for mcount functionsSteven Rostedt2008-05-231-4/+11
| | | | | | | | | | | | | | Due to debug hooks in the kernel that can change the way smp_processor_id works, use raw_smp_processor_id in mcount called functions (namely ftrace_record_ip). Currently we annotate most debug functions from calling mcount, but we should not rely on that to prevent kernel lockups. This patch uses the raw_smp_processor_id to prevent a recusive crash that can happen if a debug hook in smp_processor_id calls mcount. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* ftrace: special stacktraceIngo Molnar2008-05-231-23/+24
| | | | | Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* ftrace: trace fasterIngo Molnar2008-05-231-2/+2
| | | | | Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* ftrace: fix setting of pos in read_pipeSteven Rostedt2008-05-231-1/+1
| | | | | | | | | | In resetting the iterator in read_pipe, the reset of pos was postitioned in the wrong location with respect to the memset operation. The current code sets pos, incorrectly, to zero. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* x86: fix SMP alternatives: use mutex instead of spinlock, text_poke is sleepablePekka Paalanen2008-05-231-9/+9
| | | | | | | | | text_poke is sleepable. The original fix by Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>. Signed-off-by: Pekka Paalanen <pq@iki.fi> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* ftrace: add trace pipe header plugginSteven Rostedt2008-05-232-7/+36
| | | | | | | | | This patch adds a method for open_pipe and open_read to the pluggins so that they can add a header to the trace pipe call. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* ftrace: add logic to record overrunsSteven Rostedt2008-05-232-6/+16
| | | | | | | | | This patch sets up the infrastructure to record overruns of the tracing buffer. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* x86_64: fix kernel rodata NX settingPekka Paalanen2008-05-231-1/+1
| | | | | | | | | | | | Without CONFIG_DYNAMIC_FTRACE, mark_rodata_ro() would mark a wrong number of pages as no-execute. The bug was introduced in the patch "ftrace: dont write protect kernel text". The symptom was machine reboot after a CPU hotplug. Signed-off-by: Pekka Paalanen <pq@iki.fi> Acked-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* ftrace: fix comm on function trace outputSteven Rostedt2008-05-234-3/+15
| | | | | | | | | | | In cleaning up of the sched_switch code, the function trace recording of task comms was removed. This patch adds back the recording of comms for function trace. The output of ftrace now has the task comm instead of <...>. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* ftrace: comment codeSteven Rostedt2008-05-232-1/+141
| | | | | | | | | This is first installment of adding documentation to the ftrace. Expect many more patches of this kind in the near future. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* ftrace: modulize the number of CPU buffersSteven Rostedt2008-05-231-14/+24
| | | | | | | | | | | | Currently ftrace allocates a trace buffer for every possible CPU. Work is being done to change it to only online CPUs and add hooks to hotplug CPUS. This patch lays out the infrastructure for such a change. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* ftrace: replace simple_strtoul with strict_strtoulSteven Rostedt2008-05-231-6/+22
| | | | | | | | | Andrew Morton suggested using strict_strtoul over simple_strtoul. This patch replaces them in ftrace. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* ftrace: simple clean upsSteven Rostedt2008-05-231-13/+12
| | | | | | | | | Andrew Morton mentioned some clean ups that should be done to ftrace. This patch does some of the simple clean ups. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* ftrace: cleanupsIngo Molnar2008-05-231-6/+5
| | | | | | | no code changed. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* ftrace: simplify hexprintThomas Gleixner2008-05-231-18/+5
| | | | | | | simplify hex to ascii conversion. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* lockdep: update lockdep_recursion on graph_lockSteven Rostedt2008-05-231-0/+3
| | | | | | | | | | | With the introduction of ftrace, it is possible to recurse into the lockdep functions via the mcount call. To prevent possible lockups, updating the lockdep_recursion counter on grabbing the internal lockdep_lock should prevent deadlocks. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* ftrace: trace_entries to dynamically change trace buffer sizeSteven Rostedt2008-05-231-8/+137
| | | | | | | | | | | | | | | | | | | | | This patch adds /debug/tracing/trace_entries that allows users to see as well as modify the number of trace entries the buffers hold. The number of entries only increments in ENTRIES_PER_PAGE which is calculated by the size of an entry with the number of entries that can fit in a page. The user does not need to use an exact size, but the entries will be rounded to one of the increments. Trying to set the entries to 0 will return with -EINVAL. To avoid race conditions, the modification of the buffer size can only be done when tracing is completely disabled (current_tracer == none). A info message will be printed if a user tries to modify the buffer size when not set to none. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* ftrace: user proper API for setting RT prios in selftestSteven Rostedt2008-05-231-3/+3
| | | | | | | | | | | The wakeup selftest used an internal API for setting the test task priority. This patch fixes it to use the proper API for performing such a task. Thanks goes to Randy Dunlap for pointing out this build failure. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* ftrace: trace_pipe implement NONBLOCKSteven Rostedt2008-05-231-0/+4
| | | | | | | | | This patch implements "NONBLOCK" for trace_pipe. If the trace_pipe is opened with O_NONBLOCK, then the trace_pipe read will not block when buffer is empty. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* ftrace: return EOF in trace_pipe on change of tracerSteven Rostedt2008-05-231-0/+3
| | | | | | | | Break out of while loop with EOF when the current_trace changes. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* ftrace: restore iterator trace in pipe readSteven Rostedt2008-05-231-1/+4
| | | | | | | | | The trace iterator is reset in the read. We still need to restore the tracer that the trace_pipe was opened with. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* ftrace: allow trace_pipe to block on all readsSteven Rostedt2008-05-231-2/+0
| | | | | | | | | We expect things like "cat" to block on reads to trace_pipe. That's what trace_pipe is for. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* ftrace: fix conversion of task state to char in latency tracerAnkita Garg2008-05-231-2/+3
| | | | | | | | | | | | | | | The conversion of task states to a character in the sched_switch tracer (part of latency tracer infrastructure), seems to be incorrect. We currently do it by indexing into the state_to_char array using the state value. The state values do not map directly into the array index and are thus incorrect. The following patch addresses this issue. This is also what is being done even in the show_task() routine in kernel/sched.c The patch has been compile and run tested. Signed-off-by: Ankita Garg <ankita@in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>