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* ftrace: remove direct reference to mcount in trace codeSteven Rostedt2008-10-14
| | | | | | | | | | | | | | The mcount record method of ftrace scans objdump for references to mcount. Using mcount as the reference to test if the calls to mcount being replaced are indeed calls to mcount, this use of mcount was also caught as a location to change. Using a variable that points to the mcount address moves this reference into the data section that is not scanned, and we do not use a false location to try and modify. The warn on code was what was used to detect this bug. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* ftrace: add stack tracerSteven Rostedt2008-10-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is another tracer using the ftrace infrastructure, that examines at each function call the size of the stack. If the stack use is greater than the previous max it is recorded. You can always see (and set) the max stack size seen. By setting it to zero will start the recording again. The backtrace is also available. For example: # cat /debug/tracing/stack_max_size 1856 # cat /debug/tracing/stack_trace [<c027764d>] stack_trace_call+0x8f/0x101 [<c021b966>] ftrace_call+0x5/0x8 [<c02553cc>] clocksource_get_next+0x12/0x48 [<c02542a5>] update_wall_time+0x538/0x6d1 [<c0245913>] do_timer+0x23/0xb0 [<c0257657>] tick_do_update_jiffies64+0xd9/0xf1 [<c02576b9>] tick_sched_timer+0x4a/0xad [<c0250fe6>] __run_hrtimer+0x3e/0x75 [<c02518ed>] hrtimer_interrupt+0xf1/0x154 [<c022c870>] smp_apic_timer_interrupt+0x71/0x84 [<c021b7e9>] apic_timer_interrupt+0x2d/0x34 [<c0238597>] finish_task_switch+0x29/0xa0 [<c05abd13>] schedule+0x765/0x7be [<c05abfca>] schedule_timeout+0x1b/0x90 [<c05ab4d4>] wait_for_common+0xab/0x101 [<c05ab5ac>] wait_for_completion+0x12/0x14 [<c033cfc3>] blk_execute_rq+0x84/0x99 [<c0402470>] scsi_execute+0xc2/0x105 [<c040250a>] scsi_execute_req+0x57/0x7f [<c043afe0>] sr_test_unit_ready+0x3e/0x97 [<c043bbd6>] sr_media_change+0x43/0x205 [<c046b59f>] media_changed+0x48/0x77 [<c046b5ff>] cdrom_media_changed+0x31/0x37 [<c043b091>] sr_block_media_changed+0x16/0x18 [<c02b9e69>] check_disk_change+0x1b/0x63 [<c046f4c3>] cdrom_open+0x7a1/0x806 [<c043b148>] sr_block_open+0x78/0x8d [<c02ba4c0>] do_open+0x90/0x257 [<c02ba869>] blkdev_open+0x2d/0x56 [<c0296a1f>] __dentry_open+0x14d/0x23c [<c0296b32>] nameidata_to_filp+0x24/0x38 [<c02a1c68>] do_filp_open+0x347/0x626 [<c02967ef>] do_sys_open+0x47/0xbc [<c02968b0>] sys_open+0x23/0x2b [<c021aadd>] sysenter_do_call+0x12/0x26 I've tested this on both x86_64 and i386. 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> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* ftrace: clean up macro usageIngo Molnar2008-10-14
| | | | | | | enclose the argument in parenthesis. (especially since we cast it, which is a high prio operation) Signed-off-by: Ingo Molnar <mingo@elte.hu>
* ftrace: fix build failureStephen Rothwell2008-10-14
| | | | | | | | | | | | | | | After disabling FTRACE_MCOUNT_RECORD via a patch, a dormant build failure surfaced: kernel/trace/ftrace.c: In function 'ftrace_record_ip': kernel/trace/ftrace.c:416: error: incompatible type for argument 1 of '_spin_lock_irqsave' kernel/trace/ftrace.c:433: error: incompatible type for argument 1 of '_spin_lock_irqsave' Introduced by commit 6dad8e07f4c10b17b038e84d29f3ca41c2e55cd0 ("ftrace: add necessary locking for ftrace records"). Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* ftrace: add necessary locking for ftrace recordsSteven Rostedt2008-10-14
| | | | | | | | | | | | | | | The new design of pre-recorded mcounts and updating the code outside of kstop_machine has changed the way the records themselves are protected. This patch uses the ftrace_lock to protect the records. Note, the lock still does not need to be taken within calls that are only called via kstop_machine, since the that code can not run while the spin lock is held. Also removed the hash_lock needed for the daemon when MCOUNT_RECORD is configured. Also did a slight cleanup of an unused variable. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* ftrace: do not init module on ftrace disabledSteven Rostedt2008-10-14
| | | | | | | | If one of the self tests of ftrace has disabled the function tracer, do not run the code to convert the mcount calls in modules. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* ftrace: fix some mistakes in error messagesFrédéric Weisbecker2008-10-14
| | | | | | | | | This patch fixes some mistakes on the tracer in warning messages when debugfs fails to create tracing files. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: srostedt@redhat.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
* ftrace: dump out ftrace buffers to console on panicSteven Rostedt2008-10-14
| | | | | | | | | | | | | | | | | | | | | | | | | | At OLS I had a lot of interest to be able to have the ftrace buffers dumped on panic. Usually one would expect to uses kexec and examine the buffers after a new kernel is loaded. But sometimes the resources do not permit kdump and kexec, so having an option to still see the sequence of events up to the crash is very advantageous. This patch adds the option to have the ftrace buffers dumped to the console in the latency_trace format on a panic. When the option is set, the default entries per CPU buffer are lowered to 16384, since the writing to the serial (if that is the console) may take an awful long time otherwise. [ Changes since -v1: Got alpine to send correctly (as well as spell check working). Removed config option. Moved the static variables into ftrace_dump itself. Gave printk a log level. ] Signed-off-by: Steven Rostedt <srostedt@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* ftrace: ftrace_printk doc movedSteven Rostedt2008-10-14
| | | | | | | | | | Based on Randy Dunlap's suggestion, the ftrace_printk kernel-doc belongs with the ftrace_printk macro that should be used. Not with the __ftrace_printk internal function. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Acked-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* ftrace: printk formatting infrastructureSteven Rostedt2008-10-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds a feature that can help kernel developers debug their code using ftrace. int ftrace_printk(const char *fmt, ...); This records into the ftrace buffer using printf formatting. The entry size in the buffers are still a fixed length. A new type has been added that allows for more entries to be used for a single recording. The start of the print is still the same as the other entries. It returns the number of characters written to the ftrace buffer. For example: Having a module with the following code: static int __init ftrace_print_test(void) { ftrace_printk("jiffies are %ld\n", jiffies); return 0; } Gives me: insmod-5441 3...1 7569us : ftrace_print_test: jiffies are 4296626666 for the latency_trace file and: insmod-5441 [03] 1959.370498: ftrace_print_test jiffies are 4296626666 for the trace file. Note: Only the infrastructure should go into the kernel. It is to help facilitate debugging for other kernel developers. Calls to ftrace_printk is not intended to be left in the kernel, and should be frowned upon just like scattering printks around in the code. But having this easily at your fingertips helps the debugging go faster and bugs be solved quicker. Maybe later on, we can hook this with markers and have their printf format be sucked into ftrace output. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* ftrace: new continue entry - separate out from trace_entrySteven Rostedt2008-10-14
| | | | | | | | | | | | | | | Some tracers will need to work with more than one entry. In order to do this the trace_entry structure was split into two fields. One for the start of all entries, and one to continue an existing entry. The trace_entry structure now has a "field" entry that consists of the previous content of the trace_entry, and a "cont" entry that is just a string buffer the size of the "field" entry. Thanks to Andrew Morton for suggesting this idea. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* ftrace: remove old pointers to mcountSteven Rostedt2008-10-14
| | | | | | | | | | | | | | | | | | | | When a mcount pointer is recorded into a table, it is used to add or remove calls to mcount (replacing them with nops). If the code is removed via removing a module, the pointers still exist. At modifying the code a check is always made to make sure the code being replaced is the code expected. In-other-words, the code being replaced is compared to what it is expected to be before being replaced. There is a very small chance that the code being replaced just happens to look like code that calls mcount (very small since the call to mcount is relative). To remove this chance, this patch adds ftrace_release to allow module unloading to remove the pointers to mcount within the module. Another change for init calls is made to not trace calls marked with __init. The tracing can not be started until after init is done anyway. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* ftrace: do not show freed records in available_filter_functionsSteven Rostedt2008-10-14
| | | | | | | | Seems that freed records can appear in the available_filter_functions list. This patch fixes that. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* ftrace: enable mcount recording for modulesSteven Rostedt2008-10-14
| | | | | | | | | | | This patch enables the loading of the __mcount_section of modules and changing all the callers of mcount into nops. The modification is done before the init_module function is called, so again, we do not need to use kstop_machine to make these changes. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* ftrace: mcount call site on boot nops coreSteven Rostedt2008-10-14
| | | | | | | | | | | | | | | | | This is the infrastructure to the converting the mcount call sites recorded by the __mcount_loc section into nops on boot. It also allows for using these sites to enable tracing as normal. When the __mcount_loc section is used, the "ftraced" kernel thread is disabled. This uses the current infrastructure to record the mcount call sites as well as convert them to nops. The mcount function is kept as a stub on boot up and not converted to the ftrace_record_ip function. We use the ftrace_record_ip to only record from the table. This patch does not handle modules. That comes with a later patch. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* ftrace: create __mcount_loc sectionSteven Rostedt2008-10-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch creates a section in the kernel called "__mcount_loc". This will hold a list of pointers to the mcount relocation for each call site of mcount. For example: objdump -dr init/main.o [...] Disassembly of section .text: 0000000000000000 <do_one_initcall>: 0: 55 push %rbp [...] 000000000000017b <init_post>: 17b: 55 push %rbp 17c: 48 89 e5 mov %rsp,%rbp 17f: 53 push %rbx 180: 48 83 ec 08 sub $0x8,%rsp 184: e8 00 00 00 00 callq 189 <init_post+0xe> 185: R_X86_64_PC32 mcount+0xfffffffffffffffc [...] We will add a section to point to each function call. .section __mcount_loc,"a",@progbits [...] .quad .text + 0x185 [...] The offset to of the mcount call site in init_post is an offset from the start of the section, and not the start of the function init_post. The mcount relocation is at the call site 0x185 from the start of the .text section. .text + 0x185 == init_post + 0xa We need a way to add this __mcount_loc section in a way that we do not lose the relocations after final link. The .text section here will be attached to all other .text sections after final link and the offsets will be meaningless. We need to keep track of where these .text sections are. To do this, we use the start of the first function in the section. do_one_initcall. We can make a tmp.s file with this function as a reference to the start of the .text section. .section __mcount_loc,"a",@progbits [...] .quad do_one_initcall + 0x185 [...] Then we can compile the tmp.s into a tmp.o gcc -c tmp.s -o tmp.o And link it into back into main.o. ld -r main.o tmp.o -o tmp_main.o mv tmp_main.o main.o But we have a problem. What happens if the first function in a section is not exported, and is a static function. The linker will not let the tmp.o use it. This case exists in main.o as well. Disassembly of section .init.text: 0000000000000000 <set_reset_devices>: 0: 55 push %rbp 1: 48 89 e5 mov %rsp,%rbp 4: e8 00 00 00 00 callq 9 <set_reset_devices+0x9> 5: R_X86_64_PC32 mcount+0xfffffffffffffffc The first function in .init.text is a static function. 00000000000000a8 t __setup_set_reset_devices 000000000000105f t __setup_str_set_reset_devices 0000000000000000 t set_reset_devices The lowercase 't' means that set_reset_devices is local and is not exported. If we simply try to link the tmp.o with the set_reset_devices we end up with two symbols: one local and one global. .section __mcount_loc,"a",@progbits .quad set_reset_devices + 0x10 00000000000000a8 t __setup_set_reset_devices 000000000000105f t __setup_str_set_reset_devices 0000000000000000 t set_reset_devices U set_reset_devices We still have an undefined reference to set_reset_devices, and if we try to compile the kernel, we will end up with an undefined reference to set_reset_devices, or even worst, it could be exported someplace else, and then we will have a reference to the wrong location. To handle this case, we make an intermediate step using objcopy. We convert set_reset_devices into a global exported symbol before linking it with tmp.o and set it back afterwards. 00000000000000a8 t __setup_set_reset_devices 000000000000105f t __setup_str_set_reset_devices 0000000000000000 T set_reset_devices 00000000000000a8 t __setup_set_reset_devices 000000000000105f t __setup_str_set_reset_devices 0000000000000000 T set_reset_devices 00000000000000a8 t __setup_set_reset_devices 000000000000105f t __setup_str_set_reset_devices 0000000000000000 t set_reset_devices Now we have a section in main.o called __mcount_loc that we can place somewhere in the kernel using vmlinux.ld.S and access it to convert all these locations that call mcount into nops before starting SMP and thus, eliminating the need to do this with kstop_machine. Note, A well documented perl script (scripts/recordmcount.pl) is used to do all this in one location. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* tracing: clean up tracepoints kconfig structureIngo Molnar2008-10-14
| | | | | | | | | do not expose users to CONFIG_TRACEPOINTS - tracers can select it just fine. update ftrace to select CONFIG_TRACEPOINTS. Signed-off-by: Ingo Molnar <mingo@elte.hu>
* ftrace: port to tracepointsMathieu Desnoyers2008-10-14
| | | | | | | | | | | | Porting the trace_mark() used by ftrace to tracepoints. (cleanup) Changelog : - Change error messages : marker -> tracepoint [ mingo@elte.hu: conflict resolutions ] Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Acked-by: 'Peter Zijlstra' <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* hrtimer: prevent migration of per CPU hrtimersThomas Gleixner2008-09-29
| | | | | | | | | | | | | | Impact: per CPU hrtimers can be migrated from a dead CPU The hrtimer code has no knowledge about per CPU timers, but we need to prevent the migration of such timers and warn when such a timer is active at migration time. Explicitely mark the timers as per CPU and use a more understandable mode descriptor for the interrupts safe unlocked callback mode, which is used by hrtimer_sleeper and the scheduler code. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* Merge branch 'linus' into cpus4096Ingo Molnar2008-07-28
|\ | | | | | | | | | | | | | | Conflicts: kernel/stop_machine.c Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * stop_machine: fix up ftrace.cRusty Russell2008-07-27
| | | | | | | | | | | | | | | | | | Simple conversion. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Abhishek Sagar <sagar.abhishek@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Steven Rostedt <rostedt@goodmis.org>
* | Merge branch 'linus' into cpus4096Ingo Molnar2008-07-28
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| * tracing: remove unused variableAndrea Righi2008-07-27
| | | | | | | | | | | | | | | | | | | | Remove the following warning with CONFIG_TRACING=y: kernel/trace/trace.c: In function ‘s_next’: kernel/trace/trace.c:1186: warning: unused variable ‘last_ent’ Signed-off-by: Andrea Righi <righi.andrea@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * Merge branch 'tracing-fixes-for-linus' of ↵Linus Torvalds2008-07-26
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: ftrace: fix modular build ftrace: disable tracing on acpi idle calls ftrace: remove latency-tracer leftover ftrace: only trace preempt off with preempt tracer ftrace: fix 4d3702b6 (post-v2.6.26): WARNING: at kernel/lockdep.c:2731 check_flags (ftrace)
| | * ftrace: fix modular buildIngo Molnar2008-07-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | fix: ERROR: "start_critical_timings" [drivers/acpi/processor.ko] undefined! ERROR: "stop_critical_timings" [drivers/acpi/processor.ko] undefined! Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * ftrace: remove latency-tracer leftoverIngo Molnar2008-07-24
| | | | | | | | | | | | | | | | | | | | | | | | remove the :vim=ft=help tag from trace files. I used them years ago to syntax-highlight traces and forgot about this hack. Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * Merge branch 'linus' into tracing/urgentIngo Molnar2008-07-24
| | |\
| | * | ftrace: only trace preempt off with preempt tracerSteven Rostedt2008-07-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When PREEMPT_TRACER and IRQSOFF_TRACER are both configured and irqsoff tracer is running, the preempt_off sections might also be traced. Thanks to Andrew Morton for pointing out my mistake of spin_lock disabling interrupts while he was reviewing ftrace.txt. Seems that my example I used actually hit this bug. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | ftrace: fix 4d3702b6 (post-v2.6.26): WARNING: at kernel/lockdep.c:2731 ↵Steven Rostedt2008-07-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | check_flags (ftrace) On Wed, 16 Jul 2008, Vegard Nossum wrote: > When booting 4d3702b6, I got this huge thing: > > Testing tracer wakeup: <4>------------[ cut here ]------------ > WARNING: at kernel/lockdep.c:2731 check_flags+0x123/0x160() > Modules linked in: > Pid: 1, comm: swapper Not tainted 2.6.26-crashing-02127-g4d3702b6 #30 > [<c015c349>] warn_on_slowpath+0x59/0xb0 > [<c01276c6>] ? ftrace_call+0x5/0x8 > [<c012d800>] ? native_read_tsc+0x0/0x20 > [<c0158de2>] ? sub_preempt_count+0x12/0xf0 > [<c01814eb>] ? trace_hardirqs_off+0xb/0x10 > [<c0182fbc>] ? __lock_acquire+0x2cc/0x1120 > [<c01814eb>] ? trace_hardirqs_off+0xb/0x10 > [<c01276af>] ? mcount_call+0x5/0xa > [<c017ff53>] check_flags+0x123/0x160 > [<c0183e61>] lock_acquire+0x51/0xd0 > [<c01276c6>] ? ftrace_call+0x5/0x8 > [<c0613d4f>] _spin_lock_irqsave+0x5f/0xa0 > [<c01a8d45>] ? ftrace_record_ip+0xf5/0x220 > [<c02d5413>] ? debug_locks_off+0x3/0x50 > [<c01a8d45>] ftrace_record_ip+0xf5/0x220 > [<c01276af>] mcount_call+0x5/0xa > [<c02d5418>] ? debug_locks_off+0x8/0x50 > [<c017ff27>] check_flags+0xf7/0x160 > [<c0183e61>] lock_acquire+0x51/0xd0 > [<c01276c6>] ? ftrace_call+0x5/0x8 > [<c0613d4f>] _spin_lock_irqsave+0x5f/0xa0 > [<c01affcd>] ? wakeup_tracer_call+0x6d/0xf0 > [<c01625e2>] ? _local_bh_enable+0x62/0xb0 > [<c0158ddd>] ? sub_preempt_count+0xd/0xf0 > [<c01affcd>] wakeup_tracer_call+0x6d/0xf0 > [<c0162724>] ? __do_softirq+0xf4/0x110 > [<c01afff1>] ? wakeup_tracer_call+0x91/0xf0 > [<c01276c6>] ftrace_call+0x5/0x8 > [<c0162724>] ? __do_softirq+0xf4/0x110 > [<c0158de2>] ? sub_preempt_count+0x12/0xf0 > [<c01625e2>] _local_bh_enable+0x62/0xb0 > [<c0162724>] __do_softirq+0xf4/0x110 > [<c01627ed>] do_softirq+0xad/0xb0 > [<c0162a15>] irq_exit+0xa5/0xb0 > [<c013a506>] smp_apic_timer_interrupt+0x66/0xa0 > [<c02d3fac>] ? trace_hardirqs_off_thunk+0xc/0x10 > [<c0127449>] apic_timer_interrupt+0x2d/0x34 > [<c018007b>] ? find_usage_backwards+0xb/0xf0 > [<c0613a09>] ? _spin_unlock_irqrestore+0x69/0x80 > [<c014ef32>] tg_shares_up+0x132/0x1d0 > [<c014d2a2>] walk_tg_tree+0x62/0xa0 > [<c014ee00>] ? tg_shares_up+0x0/0x1d0 > [<c014a860>] ? tg_nop+0x0/0x10 > [<c015499d>] update_shares+0x5d/0x80 > [<c0154a2f>] try_to_wake_up+0x6f/0x280 > [<c01a8b90>] ? __ftrace_modify_code+0x0/0xc0 > [<c01a8b90>] ? __ftrace_modify_code+0x0/0xc0 > [<c0154c94>] wake_up_process+0x14/0x20 > [<c01725f6>] kthread_create+0x66/0xb0 > [<c0195400>] ? do_stop+0x0/0x200 > [<c0195320>] ? __stop_machine_run+0x30/0xb0 > [<c0195340>] __stop_machine_run+0x50/0xb0 > [<c0195400>] ? do_stop+0x0/0x200 > [<c01a8b90>] ? __ftrace_modify_code+0x0/0xc0 > [<c061242d>] ? mutex_unlock+0xd/0x10 > [<c01953cc>] stop_machine_run+0x2c/0x60 > [<c01a94d3>] unregister_ftrace_function+0x103/0x180 > [<c01b0517>] stop_wakeup_tracer+0x17/0x60 > [<c01b056f>] wakeup_tracer_ctrl_update+0xf/0x30 > [<c01ab8d5>] trace_selftest_startup_wakeup+0xb5/0x130 > [<c01ab950>] ? trace_wakeup_test_thread+0x0/0x70 > [<c01aadf5>] register_tracer+0x135/0x1b0 > [<c0877d02>] init_wakeup_tracer+0xd/0xf > [<c085d437>] kernel_init+0x1a9/0x2ce > [<c061397b>] ? _spin_unlock_irq+0x3b/0x60 > [<c02d3f9c>] ? trace_hardirqs_on_thunk+0xc/0x10 > [<c0877cf5>] ? init_wakeup_tracer+0x0/0xf > [<c0182646>] ? trace_hardirqs_on_caller+0x126/0x180 > [<c02d3f9c>] ? trace_hardirqs_on_thunk+0xc/0x10 > [<c01269c8>] ? restore_nocheck_notrace+0x0/0xe > [<c085d28e>] ? kernel_init+0x0/0x2ce > [<c085d28e>] ? kernel_init+0x0/0x2ce > [<c01275fb>] kernel_thread_helper+0x7/0x10 > ======================= > ---[ end trace a7919e7f17c0a725 ]--- > irq event stamp: 579530 > hardirqs last enabled at (579528): [<c01826ab>] trace_hardirqs_on+0xb/0x10 > hardirqs last disabled at (579529): [<c01814eb>] trace_hardirqs_off+0xb/0x10 > softirqs last enabled at (579530): [<c0162724>] __do_softirq+0xf4/0x110 > softirqs last disabled at (579517): [<c01627ed>] do_softirq+0xad/0xb0 > irq event stamp: 579530 > hardirqs last enabled at (579528): [<c01826ab>] trace_hardirqs_on+0xb/0x10 > hardirqs last disabled at (579529): [<c01814eb>] trace_hardirqs_off+0xb/0x10 > softirqs last enabled at (579530): [<c0162724>] __do_softirq+0xf4/0x110 > softirqs last disabled at (579517): [<c01627ed>] do_softirq+0xad/0xb0 > PASSED > > Incidentally, the kernel also hung while I was typing in this report. Things get weird between lockdep and ftrace because ftrace can be called within lockdep internal code (via the mcount pointer) and lockdep can be called with ftrace (via spin_locks). Signed-off-by: Steven Rostedt <srostedt@redhat.com> Tested-by: Vegard Nossum <vegard.nossum@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | | cpumask: change cpumask_of_cpu_ptr to use new cpumask_of_cpuMike Travis2008-07-26
|/ / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * Replace previous instances of the cpumask_of_cpu_ptr* macros with a the new (lvalue capable) generic cpumask_of_cpu(). Signed-off-by: Mike Travis <travis@sgi.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jack Steiner <steiner@sgi.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | / markers: fix sparse integer as NULL pointer warningHarvey Harrison2008-07-25
| |/ |/| | | | | | | | | | | | | | | kernel/trace/trace_sysprof.c:164:20: warning: Using plain integer as NULL pointer Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | cpumask: Replace cpumask_of_cpu with cpumask_of_cpu_ptrMike Travis2008-07-18
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * This patch replaces the dangerous lvalue version of cpumask_of_cpu with new cpumask_of_cpu_ptr macros. These are patterned after the node_to_cpumask_ptr macros. In general terms, if there is a cpumask_of_cpu_map[] then a pointer to the cpumask_of_cpu_map[cpu] entry is used. The cpumask_of_cpu_map is provided when there is a large NR_CPUS count, reducing greatly the amount of code generated and stack space used for cpumask_of_cpu(). The pointer to the cpumask_t value is needed for calling set_cpus_allowed_ptr() to reduce the amount of stack space needed to pass the cpumask_t value. If there isn't a cpumask_of_cpu_map[], then a temporary variable is declared and filled in with value from cpumask_of_cpu(cpu) as well as a pointer variable pointing to this temporary variable. Afterwards, the pointer is used to reference the cpumask value. The compiler will optimize out the extra dereference through the pointer as well as the stack space used for the pointer, resulting in identical code. A good example of the orthogonal usages is in net/sunrpc/svc.c: case SVC_POOL_PERCPU: { unsigned int cpu = m->pool_to[pidx]; cpumask_of_cpu_ptr(cpumask, cpu); *oldmask = current->cpus_allowed; set_cpus_allowed_ptr(current, cpumask); return 1; } case SVC_POOL_PERNODE: { unsigned int node = m->pool_to[pidx]; node_to_cpumask_ptr(nodecpumask, node); *oldmask = current->cpus_allowed; set_cpus_allowed_ptr(current, nodecpumask); return 1; } Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* Merge branch 'tracing/ftrace' into auto-ftrace-nextIngo Molnar2008-07-14
|\
| * ftrace: build fix for ftraced_suspendIngo Molnar2008-07-11
| | | | | | | | | | | | | | | | | | | | fix: kernel/trace/ftrace.c:1615: error: 'ftraced_suspend' undeclared (first use in this function) kernel/trace/ftrace.c:1615: error: (Each undeclared identifier is reported only once kernel/trace/ftrace.c:1615: error: for each function it appears in.) Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * ftrace: separate out the function enabled variableSteven Rostedt2008-07-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently the function tracer uses the global tracer_enabled variable that is used to keep track if the tracer is enabled or not. The function tracing startup needs to be separated out, otherwise the internal happenings of the tracer startup is also recorded. This patch creates a ftrace_function_enabled variable to all the starting of the function traces to happen after everything has been started. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Cc: Steven Rostedt <srostedt@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * ftrace: add ftrace_kill_atomicSteven Rostedt2008-07-11
| | | | | | | | | | | | | | | | | | | | | | | | | | It has been suggested that I add a way to disable the function tracer on an oops. This code adds a ftrace_kill_atomic. It is not meant to be used in normal situations. It will disable the ftrace tracer, but will not perform the nice shutdown that requires scheduling. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Cc: Steven Rostedt <srostedt@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * ftrace: use current CPU for function startupSteven Rostedt2008-07-11
| | | | | | | | | | | | | | | | | | | | | | | | | | This is more of a clean up. Currently the function tracer initializes the tracer with which ever CPU was last used for tracing. This value isn't realy useful for function tracing, but at least it should be something other than a random number. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Cc: Steven Rostedt <srostedt@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * ftrace: start wakeup tracing after setting function tracerSteven Rostedt2008-07-11
| | | | | | | | | | | | | | | | | | | | | | Enabling the wakeup tracer before enabling the function tracing causes some strange results due to the dynamic enabling of the functions. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Cc: Steven Rostedt <srostedt@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * ftrace: check proper config for preempt typeSteven Rostedt2008-07-11
| | | | | | | | | | | | | | | | | | | | There is no CONFIG_PREEMPT_DESKTOP. Use the proper entry CONFIG_PREEMPT. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Cc: Steven Rostedt <srostedt@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * ftrace: define function trace nopSteven Rostedt2008-07-11
| | | | | | | | | | | | | | | | | | | | | | When CONFIG_FTRACE is not enabled, the tracing_start_functon_trace and tracing_stop_function_trace should be nops. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Cc: Steven Rostedt <srostedt@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * ftrace: move sched_switch enable after markersSteven Rostedt2008-07-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We have two markers now that are enabled on sched_switch. One that records the context switching and the other that records task wake ups. Currently we enable the tracing first and then set the markers. This causes some confusing traces: # tracer: sched_switch # # TASK-PID CPU# TIMESTAMP FUNCTION # | | | | | trace-cmd-3973 [00] 115.834817: 3973:120:R + 3: 0:S trace-cmd-3973 [01] 115.834910: 3973:120:R + 6: 0:S trace-cmd-3973 [02] 115.834910: 3973:120:R + 9: 0:S trace-cmd-3973 [03] 115.834910: 3973:120:R + 12: 0:S trace-cmd-3973 [02] 115.834910: 3973:120:R + 9: 0:S <idle>-0 [02] 115.834910: 0:140:R ==> 3973:120:R Here we see that trace-cmd with PID 3973 wakes up task 9 but the next line shows the idle task doing a context switch to task 3973. Enabling the tracing to _after_ the markers are set creates a much saner output: # tracer: sched_switch # # TASK-PID CPU# TIMESTAMP FUNCTION # | | | | | <idle>-0 [02] 7922.634225: 0:140:R ==> 4790:120:R trace-cmd-4789 [03] 7922.634225: 0:140:R + 4790:120:R Signed-off-by: Steven Rostedt <srostedt@redhat.com> Cc: Steven Rostedt <srostedt@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | Merge branch 'tracing/sysprof' into auto-ftrace-nextIngo Molnar2008-07-10
|\ \
| * | sysprof: make it depend on X86Thomas Gleixner2008-05-24
| | | | | | | | | | | | Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | ftrace/sysprof: don't trace the user stack if we are a kernel thread.Soeren Sandmann2008-05-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Check that current->mm is non-NULL before attempting to trace the user stack. Also take depth of the kernel stack into account when comparing against sample_max_depth. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | sysprof: update copyrightsIngo Molnar2008-05-23
| | | | | | | | | | | | | | | Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | sysprof: kernel traceSoeren Sandmann Pedersen2008-05-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | add kernel backtracing to the sysprof tracer. change the format of the data, so that type=0 means beginning of stack trace, 1 means kernel address, 2 means user address, and 3 means end of trace. EIP addresses are no longer distinguished from return addresses, mostly because sysprof userspace doesn't make use of it. It may be worthwhile adding this back in though, just in case it becomes interesting. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | ftrace: make it more available in the KconfigThomas Gleixner2008-05-23
| | | | | | | | | | | | Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | ftrace: fix __trace_special()Thomas Gleixner2008-05-23
| | | | | | | | | | | | Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | ftrace: remove notraceThomas Gleixner2008-05-23
| | | | | | | | | | | | | | | | | | Remove the notrace annotations. The build logic takes care of that. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | ftrace: sysprof updatesIngo Molnar2008-05-23
| | | | | | | | | | | | | | | | | | | | | make the sample period configurable. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>