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* ring-buffer: Check for valid buffer before changing sizeSteven Rostedt2012-05-231-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On some machines the number of possible CPUS is not the same as the number of CPUs that is on the machine. Ftrace uses possible_cpus to update the tracing structures but the ring buffer only allocates per cpu buffers for online CPUs when they come up. When the wakeup tracer was enabled in such a case, the ftrace code enabled all possible cpu buffers, but the code in ring_buffer_resize() did not check to see if the buffer in question was allocated. Since boot up CPUs did not match possible CPUs it caused the following crash: BUG: unable to handle kernel NULL pointer dereference at 00000020 IP: [<c1097851>] ring_buffer_resize+0x16a/0x28d *pde = 00000000 Oops: 0000 [#1] PREEMPT SMP Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: [last unloaded: scsi_wait_scan] Pid: 1387, comm: bash Not tainted 3.4.0-test+ #13 /DG965MQ EIP: 0060:[<c1097851>] EFLAGS: 00010217 CPU: 0 EIP is at ring_buffer_resize+0x16a/0x28d EAX: f5a14340 EBX: f6026b80 ECX: 00000ff4 EDX: 00000ff3 ESI: 00000000 EDI: 00000002 EBP: f4275ecc ESP: f4275eb0 DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 CR0: 80050033 CR2: 00000020 CR3: 34396000 CR4: 000007d0 DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000 DR6: ffff0ff0 DR7: 00000400 Process bash (pid: 1387, ti=f4274000 task=f4380cb0 task.ti=f4274000) Stack: c109cf9a f6026b98 00000162 00160f68 00000006 00160f68 00000002 f4275ef0 c109d013 f4275ee8 c123b72a c1c0bf00 c1cc81dc 00000005 f4275f98 00000007 f4275f70 c109d0c7 7700000e 75656b61 00000070 f5e90900 f5c4e198 00000301 Call Trace: [<c109cf9a>] ? tracing_set_tracer+0x115/0x1e9 [<c109d013>] tracing_set_tracer+0x18e/0x1e9 [<c123b72a>] ? _copy_from_user+0x30/0x46 [<c109d0c7>] tracing_set_trace_write+0x59/0x7f [<c10ec01e>] ? fput+0x18/0x1c6 [<c11f8732>] ? security_file_permission+0x27/0x2b [<c10eaacd>] ? rw_verify_area+0xcf/0xf2 [<c10ec01e>] ? fput+0x18/0x1c6 [<c109d06e>] ? tracing_set_tracer+0x1e9/0x1e9 [<c10ead77>] vfs_write+0x8b/0xe3 [<c10ebead>] ? fget_light+0x30/0x81 [<c10eaf54>] sys_write+0x42/0x63 [<c1834fbf>] sysenter_do_call+0x12/0x28 This happens with the latency tracer as the ftrace code updates the saved max buffer via its cpumask and not with a global setting. Adding a check in ring_buffer_resize() to make sure the buffer being resized exists, fixes the problem. Cc: Vaibhav Nagarnaik <vnagarnaik@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* Merge branch 'tip/perf/core-2' of ↵Ingo Molnar2012-05-212-29/+17
|\ | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace into perf/core
| * tracing: Remove kernel_lock annotationsRichard Weinberger2012-05-191-2/+0
| | | | | | | | | | | | | | | | | | The BKL is gone, these annotations are useless. Link: http://lkml.kernel.org/r/1320654202-4433-1-git-send-email-richard@nod.at Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Fix initial buffer_size_kb stateVaibhav Nagarnaik2012-05-191-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make sure that the state of buffer_size_kb is initialized correctly and returns actual size of the ring buffer. Link: http://lkml.kernel.org/r/1336066834-1673-1-git-send-email-vnagarnaik@google.com Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Laurent Chavey <chavey@google.com> Cc: Justin Teravest <teravest@google.com> Cc: David Sharp <dhsharp@google.com> Signed-off-by: Vaibhav Nagarnaik <vnagarnaik@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * ring-buffer: Merge separate resize loopsVaibhav Nagarnaik2012-05-191-26/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are 2 separate loops to resize cpu buffers that are online and offline. Merge them to make the code look better. Also change the name from update_completion to update_done to allow shorter lines. Link: http://lkml.kernel.org/r/1337372991-14783-1-git-send-email-vnagarnaik@google.com Cc: Laurent Chavey <chavey@google.com> Cc: Justin Teravest <teravest@google.com> Cc: David Sharp <dhsharp@google.com> Signed-off-by: Vaibhav Nagarnaik <vnagarnaik@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | Merge branch 'perf/core' of ↵Ingo Molnar2012-05-215-6/+17
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core Fixes for perf/core: - Rename some perf_target methods to avoid double negation, from Namhyung Kim. - Revert change to use per task events with inheritance, from Namhyung Kim. - Events should start disabled till children starts running, from David Ahern. Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * Merge remote-tracking branch 'tip/perf/urgent' into perf/coreArnaldo Carvalho de Melo2012-05-185-6/+17
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge reason: We are going to queue up a dependent patch: "perf tools: Move parse event automated tests to separated object" That depends on: commit e7c72d8 perf tools: Add 'G' and 'H' modifiers to event parsing Conflicts: tools/perf/builtin-stat.c Conflicted with the recent 'perf_target' patches when checking the result of perf_evsel open routines to see if a retry is needed to cope with older kernels where the exclude guest/host perf_event_attr bits were not used. Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| | * tracing: Do not enable function event with enableSteven Rostedt2012-05-102-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With the adding of function tracing event to perf, it caused a side effect that produces the following warning when enabling all events in ftrace: # echo 1 > /sys/kernel/debug/tracing/events/enable [console] event trace: Could not enable event function This is because when enabling all events via the debugfs system it ignores events that do not have a ->reg() function assigned. This was to skip over the ftrace internal events (as they are not TRACE_EVENTs). But as the ftrace function event now has a ->reg() function attached to it for use with perf, it is no longer ignored. Worse yet, this ->reg() function is being called when it should not be. It returns an error and causes the above warning to be printed. By adding a new event_call flag (TRACE_EVENT_FL_IGNORE_ENABLE) and have all ftrace internel event structures have it set, setting the events/enable will no longe try to incorrectly enable the function event and does not warn. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| | * tracing: Fix stacktrace of latency tracers (irqsoff and friends)Steven Rostedt2012-04-191-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While debugging a latency with someone on IRC (mirage335) on #linux-rt (OFTC), we discovered that the stacktrace output of the latency tracers (preemptirqsoff) was empty. This bug was caused by the creation of the dynamic length stack trace again (like commit 12b5da3 "tracing: Fix ent_size in trace output" was). This bug is caused by the latency tracers requiring the next event to determine the time between the current event and the next. But by grabbing the next event, the iter->ent_size is set to the next event instead of the current one. As the stacktrace event is the last event, this makes the ent_size zero and causes nothing to be printed for the stack trace. The dynamic stacktrace uses the ent_size to determine how much of the stack can be printed. The ent_size of zero means no stack. The simple fix is to save the iter->ent_size before finding the next event. Note, mirage335 asked to remain anonymous from LKML and git, so I will not add the Reported-by and Tested-by tags, even though he did report the issue and tested the fix. Cc: stable@vger.kernel.org # 3.1+ Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| | * tracing: Fix regression with tracing_onSteven Rostedt2012-04-161-3/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The change to make tracing_on affect only the ftrace ring buffer, caused a bug where it wont affect any ring buffer. The problem was that the buffer of the trace_array was passed to the write function and not the trace array itself. The trace_array can change the buffer when running a latency tracer. If this happens, then the buffer being disabled may not be the buffer currently used by ftrace. This will cause the tracing_on file to become useless. The simple fix is to pass the trace_array to the write function instead of the buffer. Then the actual buffer may be changed. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| | * tracing: Fix build breakage without CONFIG_PERF_EVENTS (again)Mark Brown2012-04-141-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Today's -next fails to link for me: kernel/built-in.o:(.data+0x178e50): undefined reference to `perf_ftrace_event_register' It looks like multiple fixes have been merged for the issue fixed by commit fa73dc9 (tracing: Fix build breakage without CONFIG_PERF_EVENTS) though I can't identify the other changes that have gone in at the minute, it's possible that the changes which caused the breakage fixed by the previous commit got dropped but the fix made it in. Link: http://lkml.kernel.org/r/1334307179-21255-1-git-send-email-broonie@opensource.wolfsonmicro.com Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | | ftrace: Remove selecting FRAME_POINTER with FUNCTION_TRACERSteven Rostedt2012-05-171-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The function tracer will enable the -pg option with gcc, which requires that frame pointers. When FRAME_POINTER is defined in the kernel config it adds the gcc option -fno-omit-frame-pointer which causes some problems on some architectures. For those architectures, the FRAME_POINTER select was not set. When FUNCTION_TRACER was selected on these architectures that can not have -fno-omit-frame-pointer, the -pg option is still set. But when FRAME_POINTER is not selected, the kernel config would add the gcc option -fomit-frame-pointer. Adding this option is incompatible with -pg even on archs that do not need frame pointers with -pg. The answer to this was to just not add either -fno-omit-frame-pointer or -fomit-frame-pointer on these archs that want function tracing but do not set FRAME_POINTER. As it turns out, for archs that require frame pointers for function tracing, the same can be used. If gcc requires frame pointers with -pg, it will simply add it. The best thing to do is not select FRAME_POINTER when function tracing is selected, and let gcc add it if needed. Only add the -fno-omit-frame-pointer when something else selects FRAME_POINTER, but do not add -fomit-frame-pointer if function tracing is selected. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | | ftrace/x86: Have x86 ftrace use the ftrace_modify_all_code()Steven Rostedt2012-05-171-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | To remove duplicate code, have the ftrace arch_ftrace_update_code() use the generic ftrace_modify_all_code(). This requires that the default ftrace_replace_code() becomes a weak function so that an arch may override it. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | | ftrace: Make ftrace_modify_all_code() global for archs to useSteven Rostedt2012-05-171-8/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | Rename __ftrace_modify_code() to ftrace_modify_all_code() and make it global for all archs to use. This will remove the duplication of code, as archs that can modify code without stop_machine() can use it directly outside of the stop_machine() call. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | | ftrace: Return record ip addr for ftrace_location()Steven Rostedt2012-05-171-6/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ftrace_location() is passed an addr, and returns 1 if the addr is on a ftrace nop (or caller to ftrace_caller), and 0 otherwise. To let kprobes know if it should move a breakpoint or not, it must return the actual addr that is the start of the ftrace nop. This way a kprobe placed on the location of a ftrace nop, can instead be placed on the instruction after the nop. Even if the probe addr is on the second or later byte of the nop, it can simply be moved forward. Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | | ftrace: Consolidate ftrace_location() and ftrace_text_reserved()Steven Rostedt2012-05-171-40/+40
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Both ftrace_location() and ftrace_text_reserved() do basically the same thing. They search to see if an address is in the ftace table (contains an address that may change from nop to call ftrace_caller). The difference is that ftrace_location() searches a single address, but ftrace_text_reserved() searches a range. This also makes the ftrace_text_reserved() faster as it now uses a bsearch() instead of linearly searching all the addresses within a page. Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | | ftrace: Speed up search by skipping pages by addressSteven Rostedt2012-05-171-6/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As all records in a page of the ftrace table are sorted, we can speed up the search algorithm by checking if the address to look for falls in between the first and last record ip on the page. This speeds up both the ftrace_location() and ftrace_text_reserved() algorithms, as it can skip full pages when the search address is not in them. Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | | ftrace: Remove extra helper functionsSteven Rostedt2012-05-171-37/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The ftrace_record_ip() and ftrace_alloc_dyn_node() were from the time of the ftrace daemon. Although they were still used, they still make things a bit more complex than necessary. Move the code into the one function that uses it, and remove the helper functions. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | | ftrace: Sort all function addresses, not just per pageSteven Rostedt2012-05-171-12/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of just sorting the ip's of the functions per ftrace page, sort the entire list before adding them to the ftrace pages. This will allow the bsearch algorithm to be sped up as it can also sort by pages, not just records within a page. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | | tracing: change CPU ring buffer state from tracing_cpumaskVaibhav Nagarnaik2012-05-171-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | According to Documentation/trace/ftrace.txt: tracing_cpumask: This is a mask that lets the user only trace on specified CPUS. The format is a hex string representing the CPUS. The tracing_cpumask currently doesn't affect the tracing state of per-CPU ring buffers. This patch enables/disables CPU recording as its corresponding bit in tracing_cpumask is set/unset. Link: http://lkml.kernel.org/r/1336096792-25373-3-git-send-email-vnagarnaik@google.com Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Laurent Chavey <chavey@google.com> Cc: Justin Teravest <teravest@google.com> Cc: David Sharp <dhsharp@google.com> Signed-off-by: Vaibhav Nagarnaik <vnagarnaik@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | | tracing: Check return value of tracing_dentry_percpu()Namhyung Kim2012-05-171-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If tracing_dentry_percpu() failed, tracing_init_debugfs_percpu() will try to create each cpu directories on debugfs' root directory as d_percpu is NULL. Link: http://lkml.kernel.org/r/1335143517-2285-1-git-send-email-namhyung.kim@lge.com Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Signed-off-by: Namhyung Kim <namhyung.kim@lge.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | | ring-buffer: Reset head page before running self testSteven Rostedt2012-05-171-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the ring buffer does its consistency test on itself, it removes the head page, runs the tests, and then adds it back to what the "head_page" pointer was. But because the head_page pointer may lack behind the real head page (held by the link list pointer). The reset may be incorrect. Instead, if the head_page exists (it does not on first allocation) reset it back to the real head page before running the consistency tests. Then it will be put back to its original location after the tests are complete. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | | ring-buffer: Add integrity check at end of iter readSteven Rostedt2012-05-171-0/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There use to be ring buffer integrity checks after updating the size of the ring buffer. But now that the ring buffer can modify the size while the system is running, the integrity checks were removed, as they require the ring buffer to be disabed to perform the check. Move the integrity check to the reading of the ring buffer via the iterator reads (the "trace" file). As reading via an iterator requires disabling the ring buffer, it is a perfect place to have it. If the ring buffer happens to be disabled when updating the size, we still perform the integrity check. Cc: Vaibhav Nagarnaik <vnagarnaik@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | | ring-buffer: Make addition of pages in ring buffer atomicVaibhav Nagarnaik2012-05-161-25/+77
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds the capability to add new pages to a ring buffer atomically while write operations are going on. This makes it possible to expand the ring buffer size without reinitializing the ring buffer. The new pages are attached between the head page and its previous page. Link: http://lkml.kernel.org/r/1336096792-25373-2-git-send-email-vnagarnaik@google.com Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Laurent Chavey <chavey@google.com> Cc: Justin Teravest <teravest@google.com> Cc: David Sharp <dhsharp@google.com> Signed-off-by: Vaibhav Nagarnaik <vnagarnaik@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | | ring-buffer: Make removal of ring buffer pages atomicVaibhav Nagarnaik2012-05-162-76/+209
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds the capability to remove pages from a ring buffer without destroying any existing data in it. This is done by removing the pages after the tail page. This makes sure that first all the empty pages in the ring buffer are removed. If the head page is one in the list of pages to be removed, then the page after the removed ones is made the head page. This removes the oldest data from the ring buffer and keeps the latest data around to be read. To do this in a non-racey manner, tracing is stopped for a very short time while the pages to be removed are identified and unlinked from the ring buffer. The pages are freed after the tracing is restarted to minimize the time needed to stop tracing. The context in which the pages from the per-cpu ring buffer are removed runs on the respective CPU. This minimizes the events not traced to only NMI trace contexts. Link: http://lkml.kernel.org/r/1336096792-25373-1-git-send-email-vnagarnaik@google.com Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Laurent Chavey <chavey@google.com> Cc: Justin Teravest <teravest@google.com> Cc: David Sharp <dhsharp@google.com> Signed-off-by: Vaibhav Nagarnaik <vnagarnaik@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | | tracing: Clean up tracing_mark_write()Steven Rostedt2012-05-161-13/+11
|/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | On gcc 4.5 the function tracing_mark_write() would give a warning of page2 being uninitialized. This is due to a bug in gcc because the logic prevents page2 from being used uninitialized, and gcc 4.6+ does not complain (correctly). Instead of adding a "unitialized" around page2, which could show a bug later on, I combined page1 and page2 into an array map_pages[]. This binds the two and the two are modified according to nr_pages (what gcc 4.5 seems to ignore). This no longer gives a warning with gcc 4.5 nor with gcc 4.6. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | tracing: Remove ftrace_disable/enable_cpu()Steven Rostedt2012-05-091-42/+2
| | | | | | | | | | | | | | | | | | The ftrace_disable_cpu() and ftrace_enable_cpu() functions were needed back before the ring buffer was lockless. Now that the ring buffer is lockless (and has been for some time), these functions serve no purpose, and unnecessarily slow down operations of the tracer. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | tracing: Use seq_*_private interface for some seq filesJiri Olsa2012-05-092-58/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It's appropriate to use __seq_open_private interface to open some of trace seq files, because it covers all steps we are duplicating in tracing code - zallocating the iterator and setting it as seq_file's private. Using this for following files: trace available_filter_functions enabled_functions Link: http://lkml.kernel.org/r/1335342219-2782-5-git-send-email-jolsa@redhat.com Signed-off-by: Jiri Olsa <jolsa@redhat.com> [ Fixed warnings for: kernel/trace/trace.c: In function '__tracing_open': kernel/trace/trace.c:2418:11: warning: unused variable 'ret' [-Wunused-variable] kernel/trace/trace.c:2417:19: warning: unused variable 'm' [-Wunused-variable] ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | ring-buffer: Add per_cpu ring buffer control filesVaibhav Nagarnaik2012-04-243-147/+293
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a debugfs entry under per_cpu/ folder for each cpu called buffer_size_kb to control the ring buffer size for each CPU independently. If the global file buffer_size_kb is used to set size, the individual ring buffers will be adjusted to the given size. The buffer_size_kb will report the common size to maintain backward compatibility. If the buffer_size_kb file under the per_cpu/ directory is used to change buffer size for a specific CPU, only the size of the respective ring buffer is updated. When tracing/buffer_size_kb is read, it reports 'X' to indicate that sizes of per_cpu ring buffers are not equivalent. Link: http://lkml.kernel.org/r/1328212844-11889-1-git-send-email-vnagarnaik@google.com Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Michael Rubin <mrubin@google.com> Cc: David Sharp <dhsharp@google.com> Cc: Justin Teravest <teravest@google.com> Signed-off-by: Vaibhav Nagarnaik <vnagarnaik@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | tracing: Remove an unneeded check in trace_seq_buffer()Dan Carpenter2012-04-241-4/+1
| | | | | | | | | | | | | | | | | | | | | | | | memcpy() returns a pointer to "bug". Hopefully, it's not NULL here or we would already have Oopsed. Link: http://lkml.kernel.org/r/20120420063145.GA22649@elgon.mountain Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | tracing: Add percpu buffers for trace_printk()Steven Rostedt2012-04-243-49/+141
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, trace_printk() uses a single buffer to write into to calculate the size and format needed to save the trace. To do this safely in an SMP environment, a spin_lock() is taken to only allow one writer at a time to the buffer. But this could also affect what is being traced, and add synchronization that would not be there otherwise. Ideally, using percpu buffers would be useful, but since trace_printk() is only used in development, having per cpu buffers for something never used is a waste of space. Thus, the use of the trace_bprintk() format section is changed to be used for static fmts as well as dynamic ones. Then at boot up, we can check if the section that holds the trace_printk formats is non-empty, and if it does contain something, then we know a trace_printk() has been added to the kernel. At this time the trace_printk per cpu buffers are allocated. A check is also done at module load time in case a module is added that contains a trace_printk(). Once the buffers are allocated, they are never freed. If you use a trace_printk() then you should know what you are doing. A buffer is made for each type of context: normal softirq irq nmi The context is checked and the appropriate buffer is used. This allows for totally lockless usage of trace_printk(), and they no longer even disable interrupts. Requested-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* Merge branch 'akpm' (Andrew's patch-bomb)Linus Torvalds2012-04-061-16/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge batch of fixes from Andrew Morton: "The simple_open() cleanup was held back while I wanted for laggards to merge things. I still need to send a few checkpoint/restore patches. I've been wobbly about merging them because I'm wobbly about the overall prospects for success of the project. But after speaking with Pavel at the LSF conference, it sounds like they're further toward completion than I feared - apparently davem is at the "has stopped complaining" stage regarding the net changes. So I need to go back and re-review those patchs and their (lengthy) discussion." * emailed from Andrew Morton <akpm@linux-foundation.org>: (16 patches) memcg swap: use mem_cgroup_uncharge_swap fix backlight: add driver for DA9052/53 PMIC v1 C6X: use set_current_blocked() and block_sigmask() MAINTAINERS: add entry for sparse checker MAINTAINERS: fix REMOTEPROC F: typo alpha: use set_current_blocked() and block_sigmask() simple_open: automatically convert to simple_open() scripts/coccinelle/api/simple_open.cocci: semantic patch for simple_open() libfs: add simple_open() hugetlbfs: remove unregister_filesystem() when initializing module drivers/rtc/rtc-88pm860x.c: fix rtc irq enable callback fs/xattr.c:setxattr(): improve handling of allocation failures fs/xattr.c:listxattr(): fall back to vmalloc() if kmalloc() failed fs/xattr.c: suppress page allocation failure warnings from sys_listxattr() sysrq: use SEND_SIG_FORCED instead of force_sig() proc: fix mount -t proc -o AAA
| * simple_open: automatically convert to simple_open()Stephen Boyd2012-04-061-16/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Many users of debugfs copy the implementation of default_open() when they want to support a custom read/write function op. This leads to a proliferation of the default_open() implementation across the entire tree. Now that the common implementation has been consolidated into libfs we can replace all the users of this function with simple_open(). This replacement was done with the following semantic patch: <smpl> @ open @ identifier open_f != simple_open; identifier i, f; @@ -int open_f(struct inode *i, struct file *f) -{ ( -if (i->i_private) -f->private_data = i->i_private; | -f->private_data = i->i_private; ) -return 0; -} @ has_open depends on open @ identifier fops; identifier open.open_f; @@ struct file_operations fops = { ... -.open = open_f, +.open = simple_open, ... }; </smpl> [akpm@linux-foundation.org: checkpatch fixes] Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Julia Lawall <Julia.Lawall@lip6.fr> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | tracing: Fix ent_size in trace outputSteven Rostedt2012-03-271-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When reading the trace file, the records of each of the per_cpu buffers are examined to find the next event to print out. At the point of looking at the event, the size of the event is recorded. But if the first event is chosen, the other events in the other CPU buffers will reset the event size that is stored in the iterator descriptor, causing the event size passed to the output functions to be incorrect. In most cases this is not a problem, but for the case of stack traces, it is. With the change to the stack tracing to record a dynamic number of back traces, the output depends on the size of the entry instead of the fixed 8 back traces. When the entry size is not correct, the back traces would not be fully printed. Note, reading from the per-cpu trace files were not affected. Reported-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | Merge branch 'linus' into perf/urgentIngo Molnar2012-03-261-1/+1
|\| | | | | | | | | | | Merge reason: we need to fix a non-trivial merge conflict. Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * Merge branch 'for-linus' of ↵Linus Torvalds2012-03-211-1/+1
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs pile 1 from Al Viro: "This is _not_ all; in particular, Miklos' and Jan's stuff is not there yet." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (64 commits) ext4: initialization of ext4_li_mtx needs to be done earlier debugfs-related mode_t whack-a-mole hfsplus: add an ioctl to bless files hfsplus: change finder_info to u32 hfsplus: initialise userflags qnx4: new helper - try_extent() qnx4: get rid of qnx4_bread/qnx4_getblk take removal of PF_FORKNOEXEC to flush_old_exec() trim includes in inode.c um: uml_dup_mmap() relies on ->mmap_sem being held, but activate_mm() doesn't hold it um: embed ->stub_pages[] into mmu_context gadgetfs: list_for_each_safe() misuse ocfs2: fix leaks on failure exits in module_init ecryptfs: make register_filesystem() the last potential failure exit ntfs: forgets to unregister sysctls on register_filesystem() failure logfs: missing cleanup on register_filesystem() failure jfs: mising cleanup on register_filesystem() failure make configfs_pin_fs() return root dentry on success configfs: configfs_create_dir() has parent dentry in dentry->d_parent configfs: sanitize configfs_create() ...
| | * constify path argument of trace_seq_path()Al Viro2012-03-211-1/+1
| | | | | | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | | Merge branch 'tip/perf/urgent' of ↵Ingo Molnar2012-03-242-5/+13
|\ \ \ | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace into perf/urgent
| * | | tracing: Fix ftrace stack trace entriesWolfgang Mauerer2012-03-222-5/+13
| | |/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | 8 hex characters tell only half the tale for 64 bit CPUs, so use the appropriate length. Link: http://lkml.kernel.org/r/1332411501-8059-2-git-send-email-wolfgang.mauerer@siemens.com Cc: stable@vger.kernel.org Signed-off-by: Wolfgang Mauerer <wolfgang.mauerer@siemens.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | | tracing: Fix build breakage without CONFIG_PERF_EVENTSMark Brown2012-03-131-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Today's -next fails to build for me: CC kernel/trace/trace_export.o In file included from kernel/trace/trace_export.c:197: kernel/trace/trace_entries.h:58: error: 'perf_ftrace_event_register' undeclared here (not in a function) make[2]: *** [kernel/trace/trace_export.o] Error 1 make[1]: *** [kernel/trace] Error 2 make: *** [kernel] Error 2 because as of ced390 (ftrace, perf: Add support to use function tracepoint in perf) perf_trace_event_register() is declared in trace.h only if CONFIG_PERF_EVENTS is enabled but I don't have that set. Ensure that we always have a definition of perf_trace_event_register() by making the definition unconditional. Link: http://lkml.kernel.org/r/1330426967-17067-1-git-send-email-broonie@opensource.wolfsonmicro.com Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | | ftrace: Fix function_graph for archs that test ftrace_trace_functionRajesh Bhagat2012-03-131-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When CONFIG_DYNAMIC_FTRACE is not set, some archs (ARM) test the variable function_trace_function to determine if it should call the function tracer. If it is not set to ftrace_stub, then it will call the function and return, and not call the function graph tracer. But some of these archs (ARM) do not have the assembly code to test if function tracing is enabled or not (quick stop of tracing) and it calls the helper routine ftrace_test_stop_func() instead. If function tracer is enabled and then disabled, the variable ftrace_trace_function is still set to the helper routine ftrace_test_stop_func(), and not to ftrace_stub. This will prevent the function graph tracer from ever running. Output before patch /debug/tracing # echo function > current_tracer /debug/tracing # echo function_graph > current_tracer /debug/tracing # cat trace Output after patch /debug/tracing # echo function > current_tracer /debug/tracing # echo function_graph > current_tracer /debug/tracing # cat trace 0) ! 253.375 us | } /* irq_enter */ 0) | generic_handle_irq() { 0) | handle_fasteoi_irq() { 0) 9.208 us | _raw_spin_lock(); 0) | handle_irq_event() { 0) | handle_irq_event_percpu() { Signed-off-by: Rajesh Bhagat <rajesh.lnx@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | | tracing: Keep NMI watchdog from triggering when dumping traceSteven Rostedt2012-03-021-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As ftrace_dump() (called by ftrace_dump_on_oops) disables interrupts as it dumps its output to the console, it can keep interrupts disabled for long periods of time. This is likely to trigger the NMI watchdog, and it can disrupt the output of critical data. Add a touch_nmi_watchdog() to each event that is written to the screen to keep the NMI watchdog from affecting the output. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | | tracing: Do not select FRAME_POINTER on PPCGerlando Falauto2012-02-271-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On PowerPC, FUNCTION_TRACER selects FRAME_POINTER, even though the architecture does not support it. This causes the following warning: 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) So remove the warning by adding the extra condition "if !PPC" to FUNCTION_TRACER for FRAME_POINTER selection Link: http://lkml.kernel.org/r/1330330101-8618-1-git-send-email-gerlando.falauto@keymile.com Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Signed-off-by: Gerlando Falauto <gerlando.falauto@keymile.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | | tracing/ring-buffer: Only have tracing_on disable tracing buffersSteven Rostedt2012-02-223-97/+168
| |/ |/| | | | | | | | | | | | | | | | | | | | | | | As the ring-buffer code is being used by other facilities in the kernel, having tracing_on file disable *all* buffers is not a desired affect. It should only disable the ftrace buffers that are being used. Move the code into the trace.c file and use the buffer disabling for tracing_on() and tracing_off(). This way only the ftrace buffers will be affected by them and other kernel utilities will not be confused to why their output suddenly stopped. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | ftrace, perf: Add filter support for function trace eventJiri Olsa2012-02-214-9/+168
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Adding support to filter function trace event via perf interface. It is now possible to use filter interface in the perf tool like: perf record -e ftrace:function --filter="(ip == mm_*)" ls The filter syntax is restricted to the the 'ip' field only, and following operators are accepted '==' '!=' '||', ending up with the filter strings like: ip == f1[, ]f2 ... || ip != f3[, ]f4 ... with comma ',' or space ' ' as a function separator. If the space ' ' is used as a separator, the right side of the assignment needs to be enclosed in double quotes '"', e.g.: perf record -e ftrace:function --filter '(ip == do_execve,sys_*,ext*)' ls perf record -e ftrace:function --filter '(ip == "do_execve,sys_*,ext*")' ls perf record -e ftrace:function --filter '(ip == "do_execve sys_* ext*")' ls The '==' operator adds trace filter with same effect as would be added via set_ftrace_filter file. The '!=' operator adds trace filter with same effect as would be added via set_ftrace_notrace file. The right side of the '!=', '==' operators is list of functions or regexp. to be added to filter separated by space. The '||' operator is used for connecting multiple filter definitions together. It is possible to have more than one '==' and '!=' operators within one filter string. Link: http://lkml.kernel.org/r/1329317514-8131-8-git-send-email-jolsa@redhat.com Signed-off-by: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | ftrace: Allow to specify filter field type for ftrace eventsJiri Olsa2012-02-214-47/+82
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Adding FILTER_TRACE_FN event field type for function tracepoint event, so it can be properly recognized within filtering code. Currently all fields of ftrace subsystem events share the common field type FILTER_OTHER. Since the function trace fields need special care within the filtering code we need to recognize it properly, hence adding the FILTER_TRACE_FN event type. Adding filter parameter to the FTRACE_ENTRY macro, to specify the filter field type for the event. Link: http://lkml.kernel.org/r/1329317514-8131-7-git-send-email-jolsa@redhat.com Signed-off-by: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | ftrace, perf: Add support to use function tracepoint in perfJiri Olsa2012-02-214-2/+106
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Adding perf registration support for the ftrace function event, so it is now possible to register it via perf interface. The perf_event struct statically contains ftrace_ops as a handle for function tracer. The function tracer is registered/unregistered in open/close actions. To be efficient, we enable/disable ftrace_ops each time the traced process is scheduled in/out (via TRACE_REG_PERF_(ADD|DELL) handlers). This way tracing is enabled only when the process is running. Intentionally using this way instead of the event's hw state PERF_HES_STOPPED, which would not disable the ftrace_ops. It is now possible to use function trace within perf commands like: perf record -e ftrace:function ls perf stat -e ftrace:function ls Allowed only for root. Link: http://lkml.kernel.org/r/1329317514-8131-6-git-send-email-jolsa@redhat.com Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | ftrace: Add FTRACE_ENTRY_REG macro to allow event registrationJiri Olsa2012-02-212-2/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Adding FTRACE_ENTRY_REG macro so particular ftrace entries could specify registration function and thus become accesible via perf. This will be used in upcomming patch for function trace. Link: http://lkml.kernel.org/r/1329317514-8131-5-git-send-email-jolsa@redhat.com Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | ftrace, perf: Add add/del tracepoint perf registration actionsJiri Olsa2012-02-214-1/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Adding TRACE_REG_PERF_ADD and TRACE_REG_PERF_DEL to handle perf event schedule in/out actions. The add action is invoked for when the perf event is scheduled in, while the del action is invoked when the event is scheduled out. Link: http://lkml.kernel.org/r/1329317514-8131-4-git-send-email-jolsa@redhat.com Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | ftrace, perf: Add open/close tracepoint perf registration actionsJiri Olsa2012-02-214-49/+97
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Adding TRACE_REG_PERF_OPEN and TRACE_REG_PERF_CLOSE to differentiate register/unregister from open/close actions. The register/unregister actions are invoked for the first/last tracepoint user when opening/closing the event. The open/close actions are invoked for each tracepoint user when opening/closing the event. Link: http://lkml.kernel.org/r/1329317514-8131-3-git-send-email-jolsa@redhat.com Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>