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| | * | | | | | | | | | tracing/fastboot: Use the ring-buffer timestamp for initcall entriesFrederic Weisbecker2008-11-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: Split the boot tracer entries in two parts: call and return Now that we are using the sched tracer from the boot tracer, we want to use the same timestamp than the ring-buffer to have consistent time captures between sched events and initcall events. So we get rid of the old time capture by the boot tracer and split the initcall events in two parts: call and return. This way we have the ring buffer timestamp of both. An example trace: [ 27.904149584] calling net_ns_init+0x0/0x1c0 @ 1 [ 27.904429624] initcall net_ns_init+0x0/0x1c0 returned 0 after 0 msecs [ 27.904575926] calling reboot_init+0x0/0x20 @ 1 [ 27.904655399] initcall reboot_init+0x0/0x20 returned 0 after 0 msecs [ 27.904800228] calling sysctl_init+0x0/0x30 @ 1 [ 27.905142914] initcall sysctl_init+0x0/0x30 returned 0 after 0 msecs [ 27.905287211] calling ksysfs_init+0x0/0xb0 @ 1 ##### CPU 0 buffer started #### init-1 [000] 27.905395: 1:120:R + [001] 11:115:S ##### CPU 1 buffer started #### <idle>-0 [001] 27.905425: 0:140:R ==> [001] 11:115:R init-1 [000] 27.905426: 1:120:D ==> [000] 0:140:R <idle>-0 [000] 27.905431: 0:140:R + [000] 4:115:S <idle>-0 [000] 27.905451: 0:140:R ==> [000] 4:115:R ksoftirqd/0-4 [000] 27.905456: 4:115:S ==> [000] 0:140:R udevd-11 [001] 27.905458: 11:115:R + [001] 14:115:R <idle>-0 [000] 27.905459: 0:140:R + [000] 4:115:S <idle>-0 [000] 27.905462: 0:140:R ==> [000] 4:115:R udevd-11 [001] 27.905462: 11:115:R ==> [001] 14:115:R ksoftirqd/0-4 [000] 27.905467: 4:115:S ==> [000] 0:140:R <idle>-0 [000] 27.905470: 0:140:R + [000] 4:115:S <idle>-0 [000] 27.905473: 0:140:R ==> [000] 4:115:R ksoftirqd/0-4 [000] 27.905476: 4:115:S ==> [000] 0:140:R <idle>-0 [000] 27.905479: 0:140:R + [000] 4:115:S <idle>-0 [000] 27.905482: 0:140:R ==> [000] 4:115:R ksoftirqd/0-4 [000] 27.905486: 4:115:S ==> [000] 0:140:R udevd-14 [001] 27.905499: 14:120:X ==> [001] 11:115:R udevd-11 [001] 27.905506: 11:115:R + [000] 1:120:D <idle>-0 [000] 27.905515: 0:140:R ==> [000] 1:120:R udevd-11 [001] 27.905517: 11:115:S ==> [001] 0:140:R [ 27.905557107] initcall ksysfs_init+0x0/0xb0 returned 0 after 3906 msecs [ 27.905705736] calling init_jiffies_clocksource+0x0/0x10 @ 1 [ 27.905779239] initcall init_jiffies_clocksource+0x0/0x10 returned 0 after 0 msecs [ 27.906769814] calling pm_init+0x0/0x30 @ 1 [ 27.906853627] initcall pm_init+0x0/0x30 returned 0 after 0 msecs [ 27.906997803] calling pm_disk_init+0x0/0x20 @ 1 [ 27.907076946] initcall pm_disk_init+0x0/0x20 returned 0 after 0 msecs [ 27.907222556] calling swsusp_header_init+0x0/0x30 @ 1 [ 27.907294325] initcall swsusp_header_init+0x0/0x30 returned 0 after 0 msecs [ 27.907439620] calling stop_machine_init+0x0/0x50 @ 1 init-1 [000] 27.907485: 1:120:R + [000] 2:115:S init-1 [000] 27.907490: 1:120:D ==> [000] 2:115:R kthreadd-2 [000] 27.907507: 2:115:R + [001] 15:115:R <idle>-0 [001] 27.907517: 0:140:R ==> [001] 15:115:R kthreadd-2 [000] 27.907517: 2:115:D ==> [000] 0:140:R <idle>-0 [000] 27.907521: 0:140:R + [000] 4:115:S <idle>-0 [000] 27.907524: 0:140:R ==> [000] 4:115:R udevd-15 [001] 27.907527: 15:115:D + [000] 2:115:D ksoftirqd/0-4 [000] 27.907537: 4:115:S ==> [000] 2:115:R udevd-15 [001] 27.907537: 15:115:D ==> [001] 0:140:R kthreadd-2 [000] 27.907546: 2:115:R + [000] 1:120:D kthreadd-2 [000] 27.907550: 2:115:S ==> [000] 1:120:R init-1 [000] 27.907584: 1:120:R + [000] 15: 0:D init-1 [000] 27.907589: 1:120:R + [000] 2:115:S init-1 [000] 27.907593: 1:120:D ==> [000] 15: 0:R udevd-15 [000] 27.907601: 15: 0:S ==> [000] 2:115:R ##### CPU 0 buffer started #### kthreadd-2 [000] 27.907616: 2:115:R + [001] 16:115:R ##### CPU 1 buffer started #### <idle>-0 [001] 27.907620: 0:140:R ==> [001] 16:115:R kthreadd-2 [000] 27.907621: 2:115:D ==> [000] 0:140:R udevd-16 [001] 27.907625: 16:115:D + [000] 2:115:D <idle>-0 [000] 27.907628: 0:140:R + [000] 4:115:S udevd-16 [001] 27.907629: 16:115:D ==> [001] 0:140:R <idle>-0 [000] 27.907631: 0:140:R ==> [000] 4:115:R ksoftirqd/0-4 [000] 27.907636: 4:115:S ==> [000] 2:115:R kthreadd-2 [000] 27.907644: 2:115:R + [000] 1:120:D kthreadd-2 [000] 27.907647: 2:115:S ==> [000] 1:120:R init-1 [000] 27.907657: 1:120:R + [001] 16: 0:D <idle>-0 [001] 27.907666: 0:140:R ==> [001] 16: 0:R [ 27.907703862] initcall stop_machine_init+0x0/0x50 returned 0 after 0 msecs [ 27.907850704] calling filelock_init+0x0/0x30 @ 1 [ 27.907926573] initcall filelock_init+0x0/0x30 returned 0 after 0 msecs [ 27.908071327] calling init_script_binfmt+0x0/0x10 @ 1 [ 27.908165195] initcall init_script_binfmt+0x0/0x10 returned 0 after 0 msecs [ 27.908309461] calling init_elf_binfmt+0x0/0x10 @ 1 Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | | | | | tracing/fastboot: move boot tracer structs and funcs into their own header.Frederic Weisbecker2008-11-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: Cleanups on the boot tracer and ftrace This patch bring some cleanups about the boot tracer headers. The functions and structures of this tracer have nothing related to ftrace and should have so their own header file. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | | | | | Merge branch 'tracing/function-return-tracer' into tracing/fastbootIngo Molnar2008-11-12
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| | | * | | | | | | | | tracing: add a tracer to catch execution time of kernel functionsFrederic Weisbecker2008-11-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: add new tracing plugin which can trace full (entry+exit) function calls This tracer uses the low level function return ftrace plugin to measure the execution time of the kernel functions. The first field is the caller of the function, the second is the measured function, and the last one is the execution time in nanoseconds. - v3: - HAVE_FUNCTION_RET_TRACER have been added. Each arch that support ftrace return should enable it. - ftrace_return_stub becomes ftrace_stub. - CONFIG_FUNCTION_RET_TRACER depends now on CONFIG_FUNCTION_TRACER - Return traces printing can be used for other tracers on trace.c - Adapt to the new tracing API (no more ctrl_update callback) - Correct the check of "disabled" during insertion. - Minor changes... Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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| | *-. \ \ \ \ \ \ \ \ \ Merge branches 'tracing/ftrace' and 'tracing/urgent' into tracing/coreIngo Molnar2008-11-12
| | |\ \ \ \ \ \ \ \ \ \ \ | | | |_|/ / / / / / / / / | | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: kernel/trace/ring_buffer.c
| | | * | | | | | | | | | ring-buffer: clean up warn onsSteven Rostedt2008-11-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: Restructure WARN_ONs in ring_buffer.c The current WARN_ON macros in ring_buffer.c are quite ugly. This patch cleans them up and uses a single RB_WARN_ON that returns the value of the condition. This allows the caller to abort the function if the condition is true. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | | * | | | | | | | | | ring-buffer: add reader lockSteven Rostedt2008-11-11
| | |/ / / / / / / / / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: serialize reader accesses to individual CPU ring buffers The code in the ring buffer expects only one reader at a time, but currently it puts that requirement on the caller. This is not strong enough, and this patch adds a "reader_lock" that serializes the access to the reader API of the ring buffer. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | | | | | ring-buffer: replace most bug ons with warn on and disable bufferSteven Rostedt2008-11-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch replaces most of the BUG_ONs in the ring_buffer code with RB_WARN_ON variants. It adds some more variants as needed for the replacement. This lets the buffer die nicely and still warn the user. One BUG_ON remains in the code, and that is because it detects a bad pointer passed in by the calling function, and not a bug by the ring buffer code itself. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | | | | | ftrace: prevent ftrace_special from recursionSteven Rostedt2008-11-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: stop ftrace_special from recursion The ftrace_special is used to help debug areas of the kernel. Because of this, if it is put in certain locations, the fact that it allows recursion can become a problem if the kernel developer using does not realize that. This patch changes ftrace_special to not allow recursion into itself to make it more robust. It also changes from preempt disable interrupts disable to prevent any loss of trace entries. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | | | | | Merge branch 'tracing/urgent' into tracing/ftraceIngo Molnar2008-11-11
| | |\ \ \ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: kernel/trace/trace.c
| | * | | | | | | | | | | ftrace: display start of CPU buffer in trace outputSteven Rostedt2008-11-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: change in trace output Because the trace buffers are per cpu ring buffers, the start of the trace can be confusing. If one CPU is very active at the end of the trace, its history will not go as far back as the other CPU traces. This means that output for a particular CPU may not appear for the first part of a trace. To help annotate what is happening, and to prevent any more confusion, this patch adds a line that annotates the start of a CPU buffer output. For example: automount-3495 [001] 184.596443: dnotify_parent <-vfs_write [...] automount-3495 [001] 184.596449: dput <-path_put automount-3496 [002] 184.596450: down_read_trylock <-do_page_fault [...] sshd-3497 [001] 184.597069: up_read <-do_page_fault <idle>-0 [000] 184.597074: __exit_idle <-exit_idle [...] automount-3496 [002] 184.597257: filemap_fault <-__do_fault <idle>-0 [003] 184.597261: exit_idle <-smp_apic_timer_interrupt Note, parsers of a trace output should always ignore any lines that start with a '#'. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | | | | | | ftrace: force pass of preemptoff selftestSteven Rostedt2008-11-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: preemptoff not tested in selftest Due to the BKL not being preemptable anymore, the selftest of the preemptoff code can not be tested. It requires that it is called with preemption enabled, but since the BKL is held, that is no longer the case. This patch simply skips those tests if it detects that the context is not preemptable. The following will now show up in the tests: Testing tracer preemptoff: can not test ... force PASSED Testing tracer preemptirqsoff: can not test ... force PASSED When the BKL is removed, or it becomes preemptable once again, then the tests will be performed. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | | | | | | ftrace: remove trace array ctrlSteven Rostedt2008-11-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: remove obsolete variable in trace_array structure With the new start / stop method of ftrace, the ctrl variable in the trace_array structure is now obsolete. Remove it. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | | | | | | ftrace: remove ctrl_update methodSteven Rostedt2008-11-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: Remove the ctrl_update tracer method With the new quick start/stop method of tracing, the ctrl_update method is out of date. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | | | | | | ftrace: enable trace_printk by defaultSteven Rostedt2008-11-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: have the ftrace_printk enabled on startup It is confusing to have to "echo trace_printk > /debug/tracing/iter_ctrl" after adding ftrace_printk in the kernel. Currently the trace_printk is set to off by default. ftrace_printk should only be in open kernel code when used for debugging, and thus it should be enabled by default. It may also be used to record data within a tracer, but those ftrace_printks should be within wrappers that are either enabled by trace_points or have a variable protecting the code path from being entered when the tracer is disabled. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | | | | | | ftrace: irqsoff tracer incorrect resetSteven Rostedt2008-11-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: fix to irqsoff tracer output In converting to the new start / stop ftrace handling, the irqsoff tracer start called the irqsoff reset function. irqsoff tracer is not the same as the other traces, and it resets the buffers while searching for the longest latency. The reset that the irqsoff stop method calls disables the function tracing. That means that, by starting the tracer, the function tracer is disabled incorrectly. This patch simply removes the call to reset which keeps the function tracing enabled. Reset is not needed for the irqsoff stop method. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | | | | | | ftrace: fix sched_switch APISteven Rostedt2008-11-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: fix for sched_switch that broke dynamic ftrace startup The commit: tracing/fastboot: use sched switch tracer from boot tracer broke the API of the sched_switch trace. The use of the tracing_start/stop_cmdline record is for only recording the cmdline, NOT recording the schedule switches themselves. Seeing that the boot tracer broke the API to do something that it wanted, this patch adds a new interface for the API while puting back the original interface of the old API. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | | | | | | ftrace: fix boot trace sched startupSteven Rostedt2008-11-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: boot tracer startup modified The boot tracer calls into some of the schedule tracing private functions that should not be exported. This patch cleans it up, and makes way for further changes in the ftrace infrastructure. This patch adds a api to assign a tracer array to the schedule context switch tracer. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | | | | | | ftrace: fix set_ftrace_filterSteven Rostedt2008-11-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: fix of output of set_ftrace_filter Commit ftrace: do not show freed records in available_filter_functions Removed a bit too much from the set_ftrace_filter code, where we now see all functions in the set_ftrace_filter file even when we set a filter. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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| | *-. \ \ \ \ \ \ \ \ \ \ Merge branches 'tracing/ftrace', 'tracing/fastboot', 'tracing/nmisafe' and ↵Ingo Molnar2008-11-08
| | |\ \ \ \ \ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 'tracing/urgent' into tracing/core
| | * | | | | | | | | | | | | ring-buffer: convert to raw spinlocksSteven Rostedt2008-11-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: no lockdep debugging of ring buffer The problem with running lockdep on the ring buffer is that the ring buffer is the core infrastructure of ftrace. What happens is that the tracer will start tracing the lockdep code while lockdep is testing the ring buffers locks. This can cause lockdep to fail due to testing cases that have not fully finished their locking transition. This patch converts the spin locks used by the ring buffer back into raw spin locks which lockdep does not check. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | | | | | | | | ftrace: restructure tracing start/stop infrastructureSteven Rostedt2008-11-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: change where tracing is started up and stopped Currently, when a new tracer is selected via echo'ing a tracer name into the current_tracer file, the startup is only done if tracing_enabled is set to one. If tracing_enabled is changed to zero (by echo'ing 0 into the tracing_enabled file) a full shutdown is performed. The full startup and shutdown of a tracer can be expensive and the user can lose out traces when echo'ing in 0 to the tracing_enabled file, because the process takes too long. There can also be places that the user would like to start and stop the tracer several times and doing the full startup and shutdown of a tracer might be too expensive. This patch performs the full startup and shutdown when a tracer is selected. It also adds a way to do a quick start or stop of a tracer. The quick version is just a flag that prevents the tracing from taking place, but the overhead of the code is still there. For example, the startup of a tracer may enable tracepoints, or enable the function tracer. The stop and start will just set a flag to have the tracer ignore the calls when the tracepoint or function trace is called. The overhead of the tracer may still be present when the tracer is stopped, but no tracing will occur. Setting the tracer to the 'nop' tracer (or any other tracer) will perform the shutdown of the tracer which will disable the tracepoint or disable the function tracer. The tracing_enabled file will simply start or stop tracing. This change is all internal. The end result for the user should be the same as before. If tracing_enabled is not set, no trace will happen. If tracing_enabled is set, then the trace will happen. The tracing_enabled variable is static between tracers. Enabling tracing_enabled and going to another tracer will keep tracing_enabled enabled. Same is true with disabling tracing_enabled. This patch will now provide a fast start/stop method to the users for enabling or disabling tracing. Note: There were two methods to the struct tracer that were never used: The methods start and stop. These were to be used as a hook to the reading of the trace output, but ended up not being necessary. These two methods are now used to enable the start and stop of each tracer, in case the tracer needs to do more than just not write into the buffer. For example, the irqsoff tracer must stop recording max latencies when tracing is stopped. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | | | | | | | | ftrace: soft tracing stop and startSteven Rostedt2008-11-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: add way to quickly start stop tracing from the kernel This patch adds a soft stop and start to the trace. This simply disables function tracing via the ftrace_disabled flag, and disables the trace buffers to prevent recording. The tracing code may still be executed, but the trace will not be recorded. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | | | | | | | | ftrace: add quick function trace stopSteven Rostedt2008-11-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: quick start and stop of function tracer This patch adds a way to disable the function tracer quickly without the need to run kstop_machine. It adds a new variable called function_trace_stop which will stop the calls to functions from mcount when set. This is just an on/off switch and does not handle recursion like preempt_disable(). It's main purpose is to help other tracers/debuggers start and stop tracing fuctions without the need to call kstop_machine. The config option HAVE_FUNCTION_TRACE_MCOUNT_TEST is added for archs that implement the testing of the function_trace_stop in the mcount arch dependent code. Otherwise, the test is done in the C code. x86 is the only arch at the moment that supports this. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | | | | | | | | Merge branch 'tracing/fastboot' into tracing/ftraceIngo Molnar2008-11-06
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| | | * | | | | | | | | | | | | tracing/ftrace: fix a bug when switch current tracer to sched tracerFrederic Weisbecker2008-11-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: fix boot tracer + sched tracer coupling bug Fix a bug that made the sched_switch tracer unable to run if set as the current_tracer after the boot tracer. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | | * | | | | | | | | | | | | tracing/ftrace: types and naming corrections for sched tracerFrederic Weisbecker2008-11-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: cleanup This patch applies some corrections suggested by Steven Rostedt. Change the type of shed_ref into int since it is used into a Mutex, we don't need it anymore as an atomic variable in the sched_switch tracer. Also change the name of the register mutex. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | | * | | | | | | | | | | | | tracing/fastboot: use sched switch tracer from boot tracerFrederic Weisbecker2008-11-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: enhance boot trace output with scheduling events Use the sched_switch tracer from the boot tracer. We also can trace schedule events inside the initcalls. Sched tracing is disabled after the initcall has finished and then reenabled before the next one is started. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | | * | | | | | | | | | | | | tracing/ftrace: remove unused code in sched_switch tracerFrederic Weisbecker2008-11-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: cleanup When init_sched_switch_trace() is called, it has no reason to start the sched tracer if the sched_ref is not zero. _ If this is non-zero, the tracer is already used, but we can register it to the tracing engine. There is already a security which avoid the tracer probes not to be resgistered twice. _ If this is zero, this block will not be used. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | | * | | | | | | | | | | | | tracing/ftrace: fix a race condition in sched_switch tracerFrederic Weisbecker2008-11-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: fix race condition in sched_switch tracer This patch fixes a race condition in the sched_switch tracer. If several tasks (IE: concurrent initcalls) are playing with tracing_start_cmdline_record() and tracing_stop_cmdline_record(), the following situation could happen: _ Task A and B are using the same tracepoint probe. Task A holds it. Task B is sleeping and doesn't hold it. _ Task A frees the sched tracer, then sched_ref is decremented to 0. _ Task A is preempted and hadn't yet unregistered its tracepoint probe, then B runs. _ B increments sched_ref, sees it's 1 and then guess it has to register its probe. But it has not been freed by task A. _ A lot of bad things can happen after that... Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | | * | | | | | | | | | | | | tracing/fastboot: Enable boot tracing only during initcallsFrederic Weisbecker2008-11-04
| | | |/ / / / / / / / / / / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: modify boot tracer We used to disable the initcall tracing at a specified time (IE: end of builtin initcalls). But we don't need it anymore. It will be stopped when initcalls are finished. However we want two things: _Start this tracing only after pre-smp initcalls are finished. _Since we are planning to trace sched_switches at the same time, we want to enable them only during the initcall execution. For this purpose, this patch introduce two functions to enable/disable the sched_switch tracing during boot. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | | | | | | | | ftrace: function tracer with irqs disabledSteven Rostedt2008-11-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: disable interrupts during trace entry creation (as opposed to preempt) To help with performance, I set the ftracer to not disable interrupts, and only to disable preemption. If an interrupt occurred, it would not be traced, because the function tracer protects itself from recursion. This may be faster, but the trace output might miss some traces. This patch makes the fuction trace disable interrupts, but it also adds a runtime feature to disable preemption instead. It does this by having two different tracer functions. When the function tracer is enabled, it will check to see which version is requested (irqs disabled or preemption disabled). Then it will use the corresponding function as the tracer. Irq disabling is the default behaviour, but if the user wants better performance, with the chance of missing traces, then they can choose the preempt disabled version. Running hackbench 3 times with the irqs disabled and 3 times with the preempt disabled function tracer yielded: tracing type times entries recorded ------------ -------- ---------------- irq disabled 43.393 166433066 43.282 166172618 43.298 166256704 preempt disabled 38.969 159871710 38.943 159972935 39.325 161056510 Average: irqs disabled: 43.324 166287462 preempt disabled: 39.079 160300385 preempt is 10.8 percent faster than irqs disabled. I wrote a patch to count function trace recursion and reran hackbench. With irq disabled: 1,150 times the function tracer did not trace due to recursion. with preempt disabled: 5,117,718 times. The thousand times with irq disabled could be due to NMIs, or simply a case where it called a function that was not protected by notrace. But we also see that a large amount of the trace is lost with the preempt version. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | | | | | | | | ftrace: insert in the ftrace_preempt_disable()/enable() functionsSteven Rostedt2008-11-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: use new, consolidated APIs in ftrace plugins This patch replaces the schedule safe preempt disable code with the ftrace_preempt_disable() and ftrace_preempt_enable() safe functions. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | | | | | | | | ftrace: introduce ftrace_preempt_disable()/enable()Steven Rostedt2008-11-04
| | |/ / / / / / / / / / / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: add new ftrace-plugin internal APIs Parts of the tracer needs to be careful about schedule recursion. If the NEED_RESCHED flag is set, a preempt_enable will call schedule. Inside the schedule function, the NEED_RESCHED flag is cleared. The problem arises when a trace happens in the schedule function but before NEED_RESCHED is cleared. The race is as follows: schedule() >> tracer called trace_function() preempt_disable() [ record trace ] preempt_enable() <<- here's the issue. [check NEED_RESCHED] schedule() [ Repeat the above, over and over again ] The naive approach is simply to use preempt_enable_no_schedule instead. The problem with that approach is that, although we solve the schedule recursion issue, we now might lose a preemption check when not in the schedule function. trace_function() preempt_disable() [ record trace ] [Interrupt comes in and sets NEED_RESCHED] preempt_enable_no_resched() [continue without scheduling] The way ftrace handles this problem is with the following approach: int resched; resched = need_resched(); preempt_disable_notrace(); [record trace] if (resched) preempt_enable_no_sched_notrace(); else preempt_enable_notrace(); This may seem like the opposite of what we want. If resched is set then we call the "no_sched" version?? The reason we do this is because if NEED_RESCHED is set before we disable preemption, there's two reasons for that: 1) we are in an atomic code path 2) we are already on our way to the schedule function, and maybe even in the schedule function, but have yet to clear the flag. Both the above cases we do not want to schedule. This solution has already been implemented within the ftrace infrastructure. But the problem is that it has been implemented several times. This patch encapsulates this code to two nice functions. resched = ftrace_preempt_disable(); [ record trace] ftrace_preempt_enable(resched); This way the tracers do not need to worry about getting it right. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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| | *-----. \ \ \ \ \ \ \ \ \ \ \ Merge branches 'tracing/ftrace', 'tracing/markers', 'tracing/mmiotrace', ↵Ingo Molnar2008-11-03
| | |\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 'tracing/nmisafe', 'tracing/tracepoints' and 'tracing/urgent' into tracing/core
| | | | * | | | | | | | | | | | | | ftrace: nmi safe code clean upsSteven Rostedt2008-10-31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: cleanup This patch cleans up the NMI safe code for dynamic ftrace as suggested by Andrew Morton. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | | | * | | | | | | | | | | | | | ftrace: nmi update statisticsSteven Rostedt2008-10-30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: add more debug info to /debugfs/tracing/dyn_ftrace_total_info This patch adds dynamic ftrace NMI update statistics to the /debugfs/tracing/dyn_ftrace_total_info stat file. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | | | | | | | | | | | ftrace: ftrace_dump_on_oops=[tracer]Peter Zijlstra2008-11-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: add new (optional) debug boot option In order to facilitate early boot trouble, allow one to specify a tracer on the kernel boot line. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | | | | | | | | | | | Merge commit 'v2.6.28-rc3' into tracing/ftraceIngo Molnar2008-11-03
| | |\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ | | | | |_|/ / / / / / / / / / / / / | | | |/| | | | | | | | | | | | | |
| | * | | | | | | | | | | | | | | | Merge branch 'linus' into tracing/ftraceIngo Molnar2008-10-31
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| | * | | | | | | | | | | | | | | | ftrace: ftrace dump on oops controlSteven Rostedt2008-10-27
| | | |_|/ / / / / / / / / / / / / | | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: add (default-off) dump-trace-on-oops flag Currently, ftrace is set up to dump its contents to the console if the kernel panics or oops. This can be annoying if you have trace data in the buffers and you experience an oops, but the trace data is old or static. Usually when you want ftrace to dump its contents is when you are debugging your system and you have set up ftrace to trace the events leading to an oops. This patch adds a control variable called "ftrace_dump_on_oops" that will enable the ftrace dump to console on oops. This variable is default off but a developer can enable it either through the kernel command line by adding "ftrace_dump_on_oops" or at run time by setting (or disabling) /proc/sys/kernel/ftrace_dump_on_oops. v2: Replaced /** with /* as Randy explained that kernel-doc does not yet handle variables. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | | | | | | | | | | | | Merge branch 'master' into nextJames Morris2008-12-04
| |\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ | | | |_|_|_|_|_|_|_|_|_|_|_|_|/ / | | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: fs/nfsd/nfs4recover.c Manually fixed above to use new creds API functions, e.g. nfs4_save_creds(). Signed-off-by: James Morris <jmorris@namei.org>
| * | | | | | | | | | | | | | | | Merge branch 'master' into nextJames Morris2008-11-14
| |\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ | | | |_|_|_|_|_|/ / / / / / / / / | | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: security/keys/internal.h security/keys/process_keys.c security/keys/request_key.c Fixed conflicts above by using the non 'tsk' versions. Signed-off-by: James Morris <jmorris@namei.org>
| * | | | | | | | | | | | | | | | CRED: Separate task security context from task_structDavid Howells2008-11-14
| | |_|_|_|_|_|_|_|_|_|_|_|_|_|/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Separate the task security context from task_struct. At this point, the security data is temporarily embedded in the task_struct with two pointers pointing to it. Note that the Alpha arch is altered as it refers to (E)UID and (E)GID in entry.S via asm-offsets. With comment fixes Signed-off-by: Marc Dionne <marc.c.dionne@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: James Morris <jmorris@namei.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
* | | | | | | | | | | | | | | | cpumask: change cpumask_scnprintf, cpumask_parse_user, cpulist_parse, and ↵Rusty Russell2008-12-13
| |_|/ / / / / / / / / / / / / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | cpulist_scnprintf to take pointers. Impact: change calling convention of existing cpumask APIs Most cpumask functions started with cpus_: these have been replaced by cpumask_ ones which take struct cpumask pointers as expected. These four functions don't have good replacement names; fortunately they're rarely used, so we just change them over. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Mike Travis <travis@sgi.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: paulus@samba.org Cc: mingo@redhat.com Cc: tony.luck@intel.com Cc: ralf@linux-mips.org Cc: Greg Kroah-Hartman <gregkh@suse.de> Cc: cl@linux-foundation.org Cc: srostedt@redhat.com
* | | | | | | | | | | | | | | ftrace: prevent recursionLai Jiangshan2008-11-27
| |_|_|_|_|_|_|_|_|_|_|_|_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: prevent unnecessary stack recursion if the resched flag was set before we entered, then don't reschedule. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | | | | | | | | | | | | x86, mmiotrace: fix buffer overrun detectionPekka Paalanen2008-11-23
| |_|_|_|_|_|_|_|_|_|_|_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: fix mmiotrace overrun tracing When ftrace framework moved to use the ring buffer facility, the buffer overrun detection was broken after 2.6.27 by commit | commit 3928a8a2d98081d1bc3c0a84a2d70e29b90ecf1c | Author: Steven Rostedt <rostedt@goodmis.org> | Date: Mon Sep 29 23:02:41 2008 -0400 | | ftrace: make work with new ring buffer | | This patch ports ftrace over to the new ring buffer. The detection is now fixed by using the ring buffer API. When mmiotrace detects a buffer overrun, it will report the number of lost events. People reading an mmiotrace log must know if something was missed, otherwise the data may not make sense. Signed-off-by: Pekka Paalanen <pq@iki.fi> Acked-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | | | | | | | | | | | function tracing: fix wrong position computing of stack_traceLiming Wang2008-11-21
| |_|_|_|_|_|_|_|_|_|_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: make output of stack_trace complete if buffer overruns When read buffer overruns, the output of stack_trace isn't complete. When printing records with seq_printf in t_show, if the read buffer has overruned by the current record, then this record won't be printed to user space through read buffer, it will just be dropped in this printing. When next printing, t_start should return the "*pos"th record, which is the one dropped by previous printing, but it just returns (m->private + *pos)th record. Here we use a more sane method to implement seq_operations which can be found in kernel code. Thus we needn't initialize m->private. About testing, it's not easy to overrun read buffer, but we can use seq_printf to print more padding bytes in t_show, then it's easy to check whether or not records are lost. This commit has been tested on both condition of overrun and non overrun. Signed-off-by: Liming Wang <liming.wang@windriver.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | | | | | | | | | | Merge branch 'tip/urgent' of ↵Ingo Molnar2008-11-19
|\ \ \ \ \ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into tracing/urgent
| * | | | | | | | | | | | ftrace: fix dyn ftrace filter selectionSteven Rostedt2008-11-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: clean up and fix for dyn ftrace filter selection The previous logic of the dynamic ftrace selection of enabling or disabling functions was complex and incorrect. This patch simplifies the code and corrects the usage. This simplification also makes the code more robust. Here is the correct logic: Given a function that can be traced by dynamic ftrace: If the function is not to be traced, disable it if it was enabled. (this is if the function is in the set_ftrace_notrace file) (filter is on if there exists any functions in set_ftrace_filter file) If the filter is on, and we are enabling functions: If the function is in set_ftrace_filter, enable it if it is not already enabled. If the function is not in set_ftrace_filter, disable it if it is not already disabled. Otherwise, if the filter is off and we are enabling function tracing: Enable the function if it is not already enabled. Otherwise, if we are disabling function tracing: Disable the function if it is not already disabled. This code now sets or clears the ENABLED flag in the record, and at the end it will enable the function if the flag is set, or disable the function if the flag is cleared. The parameters for the function that does the above logic is also simplified. Instead of passing in confusing "new" and "old" where they might be swapped if the "enabled" flag is not set. The old logic even had one of the above always NULL and had to be filled in. The new logic simply passes in one parameter called "nop". A "call" is calculated in the code, and at the end of the logic, when we know we need to either disable or enable the function, we can then use the "nop" and "call" properly. This code is more robust than the previous version. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>