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2009-06-10Merge branch 'tracing-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'tracing-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: function-graph: always initialize task ret_stack function-graph: move initialization of new tasks up in fork function-graph: add memory barriers for accessing task's ret_stack function-graph: enable the stack after initialization of other variables function-graph: only allocate init tasks if it was not already done Manually fix trivial conflict in kernel/trace/ftrace.c
2009-06-10Merge branch 'tracing-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (244 commits) Revert "x86, bts: reenable ptrace branch trace support" tracing: do not translate event helper macros in print format ftrace/documentation: fix typo in function grapher name tracing/events: convert block trace points to TRACE_EVENT(), fix !CONFIG_BLOCK tracing: add protection around module events unload tracing: add trace_seq_vprint interface tracing: fix the block trace points print size tracing/events: convert block trace points to TRACE_EVENT() ring-buffer: fix ret in rb_add_time_stamp ring-buffer: pass in lockdep class key for reader_lock tracing: add annotation to what type of stack trace is recorded tracing: fix multiple use of __print_flags and __print_symbolic tracing/events: fix output format of user stack tracing/events: fix output format of kernel stack tracing/trace_stack: fix the number of entries in the header ring-buffer: discard timestamps that are at the start of the buffer ring-buffer: try to discard unneeded timestamps ring-buffer: fix bug in ring_buffer_discard_commit ftrace: do not profile functions when disabled tracing: make trace pipe recognize latency format flag ...
2009-06-10Merge branch 'signal-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'signal-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86: hookup sys_rt_tgsigqueueinfo signals: implement sys_rt_tgsigqueueinfo signals: split do_tkill
2009-06-10Merge branch 'rcu-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: rcu: rcu_sched_grace_period(): kill the bogus flush_signals() rculist: use list_entry_rcu in places where it's appropriate rculist.h: introduce list_entry_rcu() and list_first_entry_rcu() rcu: Update RCU tracing documentation for __rcu_pending rcu: Add __rcu_pending tracing to hierarchical RCU RCU: make treercu be default
2009-06-10Merge branch 'locking-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: spinlock: Add missing __raw_spin_lock_flags() stub for UP mutex: add atomic_dec_and_mutex_lock(), fix locking, rtmutex.c: Documentation cleanup mutex: add atomic_dec_and_mutex_lock()
2009-06-10Merge branch 'futexes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'futexes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: futex: fix restart in wait_requeue_pi futex: fix restart for early wakeup in futex_wait_requeue_pi() futex: cleanup error exit futex: remove the wait queue futex: add requeue-pi documentation futex: remove FUTEX_REQUEUE_PI (non CMP) futex: fix futex_wait_setup key handling sparc64: extend TI_RESTART_BLOCK space by 8 bytes futex: fixup unlocked requeue pi case futex: add requeue_pi functionality futex: split out futex value validation code futex: distangle futex_requeue() futex: add FUTEX_HAS_TIMEOUT flag to restart.futex.flags rt_mutex: add proxy lock routines futex: split out fixup owner logic from futex_lock_pi() futex: split out atomic logic from futex_lock_pi() futex: add helper to find the top prio waiter of a futex futex: separate futex_wait_queue_me() logic from futex_wait()
2009-06-10Merge branch 'x86-xen-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86-xen-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (42 commits) xen: cache cr0 value to avoid trap'n'emulate for read_cr0 xen/x86-64: clean up warnings about IST-using traps xen/x86-64: fix breakpoints and hardware watchpoints xen: reserve Xen start_info rather than e820 reserving xen: add FIX_TEXT_POKE to fixmap lguest: update lazy mmu changes to match lguest's use of kvm hypercalls xen: honour VCPU availability on boot xen: add "capabilities" file xen: drop kexec bits from /sys/hypervisor since kexec isn't implemented yet xen/sys/hypervisor: change writable_pt to features xen: add /sys/hypervisor support xen/xenbus: export xenbus_dev_changed xen: use device model for suspending xenbus devices xen: remove suspend_cancel hook xen/dev-evtchn: clean up locking in evtchn xen: export ioctl headers to userspace xen: add /dev/xen/evtchn driver xen: add irq_from_evtchn xen: clean up gate trap/interrupt constants xen: set _PAGE_NX in __supported_pte_mask before pagetable construction ...
2009-06-10Merge branch 'sched-docs-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched-docs-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: sched: Document memory barriers implied by sleep/wake-up primitives
2009-06-10Merge branch 'sched-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: sched: fix typo in sched-rt-group.txt file ftrace: fix typo about map of kernel priority in ftrace.txt file. sched: properly define the sched_group::cpumask and sched_domain::span fields sched, timers: cleanup avenrun users sched, timers: move calc_load() to scheduler sched: Don't export sched_mc_power_savings on multi-socket single core system sched: emit thread info flags with stack trace sched: rt: document the risk of small values in the bandwidth settings sched: Replace first_cpu() with cpumask_first() in ILB nomination code sched: remove extra call overhead for schedule() sched: use group_first_cpu() instead of cpumask_first(sched_group_cpus()) wait: don't use __wake_up_common() sched: Nominate a power-efficient ilb in select_nohz_balancer() sched: Nominate idle load balancer from a semi-idle package. sched: remove redundant hierarchy walk in check_preempt_wakeup
2009-06-10Merge branch 'x86-kbuild-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86-kbuild-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (46 commits) x86, boot: add new generated files to the appropriate .gitignore files x86, boot: correct the calculation of ZO_INIT_SIZE x86-64: align __PHYSICAL_START, remove __KERNEL_ALIGN x86, boot: correct sanity checks in boot/compressed/misc.c x86: add extension fields for bootloader type and version x86, defconfig: update kernel position parameters x86, defconfig: update to current, no material changes x86: make CONFIG_RELOCATABLE the default x86: default CONFIG_PHYSICAL_START and CONFIG_PHYSICAL_ALIGN to 16 MB x86: document new bzImage fields x86, boot: make kernel_alignment adjustable; new bzImage fields x86, boot: remove dead code from boot/compressed/head_*.S x86, boot: use LOAD_PHYSICAL_ADDR on 64 bits x86, boot: make symbols from the main vmlinux available x86, boot: determine compressed code offset at compile time x86, boot: use appropriate rep string for move and clear x86, boot: zero EFLAGS on 32 bits x86, boot: set up the decompression stack as early as possible x86, boot: straighten out ranges to copy/zero in compressed/head*.S x86, boot: stylistic cleanups for boot/compressed/head_64.S ... Fixed trivial conflict in arch/x86/configs/x86_64_defconfig manually
2009-06-10Merge branch 'irq-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'irq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (76 commits) x86, apic: Fix dummy apic read operation together with broken MP handling x86, apic: Restore irqs on fail paths x86: Print real IOAPIC version for x86-64 x86: enable_update_mptable should be a macro sparseirq: Allow early irq_desc allocation x86, io-apic: Don't mark pin_programmed early x86, irq: don't call mp_config_acpi_gsi() if update_mptable is not enabled x86, irq: update_mptable needs pci_routeirq x86: don't call read_apic_id if !cpu_has_apic x86, apic: introduce io_apic_irq_attr x86/pci: add 4 more return parameters to IO_APIC_get_PCI_irq_vector(), fix x86: read apic ID in the !acpi_lapic case x86: apic: Fixmap apic address even if apic disabled x86: display extended apic registers with print_local_APIC and cpu_debug code x86: read apic ID in the !acpi_lapic case x86: clean up and fix setup_clear/force_cpu_cap handling x86: apic: Check rev 3 fadt correctly for physical_apic bit x86/pci: update pirq_enable_irq() to setup io apic routing x86/acpi: move setup io apic routing out of CONFIG_ACPI scope x86/pci: add 4 more return parameters to IO_APIC_get_PCI_irq_vector() ...
2009-06-09tracing: add protection around module events unloadSteven Rostedt
When reading the trace buffer, there is a race that when a module is unloaded it removes events that is stilled referenced in the buffers. This patch adds the protection around the unloading of the events from modules and the reading of the trace buffers. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-06-09tracing: add trace_seq_vprint interfaceSteven Rostedt
The code to update the print formats for events requires a vprintf format in the trace_seq. This patch adds that interface. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-06-09tracing/events: convert block trace points to TRACE_EVENT()Li Zefan
TRACE_EVENT is a more generic way to define tracepoints. Doing so adds these new capabilities to this tracepoint: - zero-copy and per-cpu splice() tracing - binary tracing without printf overhead - structured logging records exposed under /debug/tracing/events - trace events embedded in function tracer output and other plugins - user-defined, per tracepoint filter expressions ... Cons: - no dev_t info for the output of plug, unplug_timer and unplug_io events. no dev_t info for getrq and sleeprq events if bio == NULL. no dev_t info for rq_abort,...,rq_requeue events if rq->rq_disk == NULL. This is mainly because we can't get the deivce from a request queue. But this may change in the future. - A packet command is converted to a string in TP_assign, not TP_print. While blktrace do the convertion just before output. Since pc requests should be rather rare, this is not a big issue. - In blktrace, an event can have 2 different print formats, but a TRACE_EVENT has a unique format, which means we have some unused data in a trace entry. The overhead is minimized by using __dynamic_array() instead of __array(). I've benchmarked the ioctl blktrace vs the splice based TRACE_EVENT tracing: dd dd + ioctl blktrace dd + TRACE_EVENT (splice) 1 7.36s, 42.7 MB/s 7.50s, 42.0 MB/s 7.41s, 42.5 MB/s 2 7.43s, 42.3 MB/s 7.48s, 42.1 MB/s 7.43s, 42.4 MB/s 3 7.38s, 42.6 MB/s 7.45s, 42.2 MB/s 7.41s, 42.5 MB/s So the overhead of tracing is very small, and no regression when using those trace events vs blktrace. And the binary output of TRACE_EVENT is much smaller than blktrace: # ls -l -h -rw-r--r-- 1 root root 8.8M 06-09 13:24 sda.blktrace.0 -rw-r--r-- 1 root root 195K 06-09 13:24 sda.blktrace.1 -rw-r--r-- 1 root root 2.7M 06-09 13:25 trace_splice.out Following are some comparisons between TRACE_EVENT and blktrace: plug: kjournald-480 [000] 303.084981: block_plug: [kjournald] kjournald-480 [000] 303.084981: 8,0 P N [kjournald] unplug_io: kblockd/0-118 [000] 300.052973: block_unplug_io: [kblockd/0] 1 kblockd/0-118 [000] 300.052974: 8,0 U N [kblockd/0] 1 remap: kjournald-480 [000] 303.085042: block_remap: 8,0 W 102736992 + 8 <- (8,8) 33384 kjournald-480 [000] 303.085043: 8,0 A W 102736992 + 8 <- (8,8) 33384 bio_backmerge: kjournald-480 [000] 303.085086: block_bio_backmerge: 8,0 W 102737032 + 8 [kjournald] kjournald-480 [000] 303.085086: 8,0 M W 102737032 + 8 [kjournald] getrq: kjournald-480 [000] 303.084974: block_getrq: 8,0 W 102736984 + 8 [kjournald] kjournald-480 [000] 303.084975: 8,0 G W 102736984 + 8 [kjournald] bash-2066 [001] 1072.953770: 8,0 G N [bash] bash-2066 [001] 1072.953773: block_getrq: 0,0 N 0 + 0 [bash] rq_complete: konsole-2065 [001] 300.053184: block_rq_complete: 8,0 W () 103669040 + 16 [0] konsole-2065 [001] 300.053191: 8,0 C W 103669040 + 16 [0] ksoftirqd/1-7 [001] 1072.953811: 8,0 C N (5a 00 08 00 00 00 00 00 24 00) [0] ksoftirqd/1-7 [001] 1072.953813: block_rq_complete: 0,0 N (5a 00 08 00 00 00 00 00 24 00) 0 + 0 [0] rq_insert: kjournald-480 [000] 303.084985: block_rq_insert: 8,0 W 0 () 102736984 + 8 [kjournald] kjournald-480 [000] 303.084986: 8,0 I W 102736984 + 8 [kjournald] Changelog from v2 -> v3: - use the newly introduced __dynamic_array(). Changelog from v1 -> v2: - use __string() instead of __array() to minimize the memory required to store hex dump of rq->cmd(). - support large pc requests. - add missing blk_fill_rwbs_rq() in block_rq_requeue TRACE_EVENT. - some cleanups. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> LKML-Reference: <4A2DF669.5070905@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-06-09ring-buffer: fix ret in rb_add_time_stampSteven Rostedt
The update of ret got mistakenly added to the if statement of rb_try_to_discard. The variable ret should be 1 on commit and zero otherwise. [ Impact: fix compiler warning and real bug ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-06-09cpumask: alloc zeroed cpumask for static cpumask_var_tsYinghai Lu
These are defined as static cpumask_var_t so if MAXSMP is not used, they are cleared already. Avoid surprises when MAXSMP is enabled. Signed-off-by: Yinghai Lu <yinghai.lu@kernel.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-08ring-buffer: pass in lockdep class key for reader_lockPeter Zijlstra
On Sun, 7 Jun 2009, Ingo Molnar wrote: > Testing tracer sched_switch: <6>Starting ring buffer hammer > PASSED > Testing tracer sysprof: PASSED > Testing tracer function: PASSED > Testing tracer irqsoff: > ============================================= > PASSED > Testing tracer preemptoff: PASSED > Testing tracer preemptirqsoff: [ INFO: possible recursive locking detected ] > PASSED > Testing tracer branch: 2.6.30-rc8-tip-01972-ge5b9078-dirty #5760 > --------------------------------------------- > rb_consumer/431 is trying to acquire lock: > (&cpu_buffer->reader_lock){......}, at: [<c109eef7>] ring_buffer_reset_cpu+0x37/0x70 > > but task is already holding lock: > (&cpu_buffer->reader_lock){......}, at: [<c10a019e>] ring_buffer_consume+0x7e/0xc0 > > other info that might help us debug this: > 1 lock held by rb_consumer/431: > #0: (&cpu_buffer->reader_lock){......}, at: [<c10a019e>] ring_buffer_consume+0x7e/0xc0 The ring buffer is a generic structure, and can be used outside of ftrace. If ftrace traces within the use of the ring buffer, it can produce false positives with lockdep. This patch passes in a static lock key into the allocation of the ring buffer, so that different ring buffers will have their own lock class. Reported-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1244477919.13761.9042.camel@twins> [ store key in ring buffer descriptor ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-06-08async: Fix lack of boot-time console due to insufficient synchronizationLinus Torvalds
Our async work synchronization was broken by "async: make sure independent async domains can't accidentally entangle" (commit d5a877e8dd409d8c702986d06485c374b705d340), because it would report the wrong lowest active async ID when there was both running and pending async work. This caused things like no being able to read the root filesystem, resulting in missing console devices and inability to run 'init', causing a boot-time panic. This fixes it by properly returning the lowest pending async ID: if there is any running async work, that will have a lower ID than any pending work, and we should _not_ look at the pending work list. There were alternative patches from Jaswinder and James, but this one also cleans up the code by removing the pointless 'ret' variable and the unnecesary testing for an empty list around 'for_each_entry()' (if the list is empty, the for_each_entry() thing just won't execute). Fixes-bug: http://bugzilla.kernel.org/show_bug.cgi?id=13474 Reported-and-tested-by: Chris Clayton <chris2553@googlemail.com> Cc: Jaswinder Singh Rajput <jaswinder@kernel.org> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-05Merge branch 'tip/tracing/ftrace-4' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into tracing/ftrace
2009-06-04ptrace: revert "ptrace_detach: the wrong wakeup breaks the ERESTARTxxx logic"Oleg Nesterov
Commit 95a3540da9c81a5987be810e1d9a83640a366bd5 ("ptrace_detach: the wrong wakeup breaks the ERESTARTxxx logic") removed the "extra" wake_up_process() from ptrace_detach(), but as Jan pointed out this breaks the compatibility. I believe the changelog is right and this wake_up() is wrong in many ways, but GDB assumes that ptrace(PTRACE_DETACH, child, 0, 0) always wakes up the tracee. Despite the fact this breaks SIGNAL_STOP_STOPPED/group_stop_count logic, and despite the fact this wake_up_process() can break another assumption: PTRACE_DETACH with SIGSTOP should leave the tracee in TASK_STOPPED case. Because the untraced child can dequeue SIGSTOP and call do_signal_stop() before ptrace_detach() calls wake_up_process(). Revert this change for now. We need some fixes even if we we want to keep the current behaviour, but these fixes are not for 2.6.30. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Roland McGrath <roland@redhat.com> Cc: Jan Kratochvil <jan.kratochvil@redhat.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-04ptrace: tracehook_report_clone: fix false positivesOleg Nesterov
The "trace || CLONE_PTRACE" check in tracehook_report_clone() is not right, - If the untraced task does clone(CLONE_PTRACE) the new child is not traced, we must not queue SIGSTOP. - If we forked the traced task, but the tracer exits and untraces both the forking task and the new child (after copy_process() drops tasklist_lock), we should not queue SIGSTOP too. Change the code to check task_ptrace() != 0 instead. This is still racy, but the race is harmless. We can race with another tracer attaching to this child, or the tracer can exit and detach in parallel. But giwen that we didn't do wake_up_new_task() yet, the child must have the pending SIGSTOP anyway. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Roland McGrath <roland@redhat.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-04Merge branch 'tracing/ftrace' into tracing/coreIngo Molnar
Merge reason: this mini-topic had outstanding problems that delayed its merge, so it does not fast-forward. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-03tracing: add annotation to what type of stack trace is recordedSteven Rostedt
The current method of printing out a stack trace is to add a new line and print out the trace: yum-updatesd-3120 [002] 573.691303: => do_softirq => irq_exit => smp_apic_timer_interrupt => apic_timer_interrupt This looks a bit awkward, and if we have both stack and user stack traces running, it would be nice to have a title to tell them apart, although it is easy to tell by the output. This patch adds an annotation to the start of the stack traces: init-1 [003] 929.304979: <stack trace> => user_path_at => vfs_fstatat => vfs_stat => sys_newstat => system_call_fastpath cat-3459 [002] 1016.824040: <user stack trace> => <0000003aae6c0250> => <00007ffff4b06ae4> => <69636172742f6775> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-06-03tracing: fix multiple use of __print_flags and __print_symbolicSteven Whitehouse
Here is an updated patch to include the extra call to trace_seq_init() as requested. This is vs. the latest -tip tree and fixes the use of multiple __print_flags and __print_symbolic in a single tracer. Also tested to ensure its working now: mount.gfs2-2534 [000] 235.850587: gfs2_glock_queue: 8.7 glock 1:2 dequeue PR mount.gfs2-2534 [000] 235.850591: gfs2_demote_rq: 8.7 glock 1:0 demote EX to NL flags:DI mount.gfs2-2534 [000] 235.850591: gfs2_glock_queue: 8.7 glock 1:0 dequeue EX glock_workqueue-2529 [000] 235.850666: gfs2_glock_state_change: 8.7 glock 1:0 state EX => NL tgt:NL dmt:NL flags:lDpI glock_workqueue-2529 [000] 235.850672: gfs2_glock_put: 8.7 glock 1:0 state NL => IV flags:I Signed-off-by: Steven Whitehouse <swhiteho@redhat.com> LKML-Reference: <1244037123.29604.603.camel@localhost.localdomain> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-06-03tracing/events: fix output format of user stackwalimis
According to "events/ftrace/user_stack/format", fix the output of user stack. before fix: sh-1073 [000] 31.137561: <b7f274fe> <- <0804e33c> <- <080835c1> after fix: sh-1072 [000] 37.039329: => <b7f8a4fe> => <0804e33c> => <080835c1> Signed-off-by: walimis <walimisdev@gmail.com> LKML-Reference: <1244016090-7814-3-git-send-email-walimisdev@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-06-03tracing/events: fix output format of kernel stackwalimis
According to "events/ftrace/kernel_stack/format", output format of kernel stack should use "=>" instead of "<=". The second problem is that we shouldn't skip the first entry in the stack, although it seems to be duplicated when used in the "function" tracer, but events also use it. If we skip the first one, we will drop the topmost entry of the stack. The last problem is that if the last entry is ULONG_MAX(0xffffffff), we should drop it, otherwise it will print a NULL name line. before fix: sh-1072 [000] 26.957239: sched_process_fork: parent sh:1072 child sh:1073 sh-1072 [000] 26.957262: <= syscall_call <= sh-1072 [000] 26.957744: sched_switch: task sh:1072 [120] (R) ==> sh:1073 [120] sh-1072 [000] 26.957752: <= preempt_schedule <= wake_up_new_task <= do_fork <= sys_clone <= syscall_call <= After fix: sh-1075 [000] 39.791848: sched_process_fork: parent sh:1075 child sh:1076 sh-1075 [000] 39.791871: => sys_clone => syscall_call sh-1075 [000] 39.792713: sched_switch: task sh:1075 [120] (R) ==> sh:1076 [120] sh-1075 [000] 39.792722: => schedule => preempt_schedule => wake_up_new_task => do_fork => sys_clone => syscall_call Signed-off-by: walimis <walimisdev@gmail.com> LKML-Reference: <1244016090-7814-2-git-send-email-walimisdev@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-06-03tracing/trace_stack: fix the number of entries in the headerwalimis
The last entry in the stack_dump_trace is ULONG_MAX, which is not a valid entry, but max_stack_trace.nr_entries has accounted for it. So when printing the header, we should decrease it by one. Before fix, print as following, for example: Depth Size Location (53 entries) <--- should be 52 ----- ---- -------- 0) 3264 108 update_wall_time+0x4d5/0x9a0 ... 51) 80 80 syscall_call+0x7/0xb ^^^ it's correct. Signed-off-by: walimis <walimisdev@gmail.com> LKML-Reference: <1244016090-7814-1-git-send-email-walimisdev@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-06-03ring-buffer: discard timestamps that are at the start of the bufferSteven Rostedt
Every buffer page in the ring buffer includes its own time stamp. When an event is recorded to the ring buffer with a delta time greater than what can be held in the event header, a time stamp event is created. If the the create timestamp falls over to the next buffer page, it is redundant because the buffer page holds a full time stamp. This patch will try to discard the time stamp when it falls to the start of the next page. This change also fixes a issues with disarding events. If most events are discarded, timestamps will start to creep into the ring buffer. If we do not discard the timestamps then they can fill up the ring buffer over time and waste space. This change will keep time stamps from filling up over another page. If something is recorded in the buffer page, and the rest is filtered, then the time stamps can only fill up to the end of the page. [ Impact: prevent time stamps from filling ring buffer ] Reported-by: Tim Bird <tim.bird@am.sony.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-06-03ring-buffer: try to discard unneeded timestampsSteven Rostedt
There are times that a race may happen that we add a timestamp in a nested write. This timestamp would just contain a zero delta and serves no purpose. Now that we have a way to discard events, this patch will try to discard the timestamp instead of just wasting the space in the ring buffer. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-06-03ring-buffer: fix bug in ring_buffer_discard_commitTim Bird
There's a bug in ring_buffer_discard_commit. The wrong pointer is being compared in order to check if the event can be freed from the buffer rather than discarded (i.e. marked as PAD). I noticed this when I was working on duration filtering. The bug is not deadly - it just results in lots of wasted space in the buffer. All filtered events are left in the buffer and marked as discarded, rather than being removed from the buffer to make space for other events. Unfortunately, when I fixed this bug, I got errors doing a filtered function trace. Multiple TIME_EXTEND events pile up in the buffer, and trigger the following loop overage warning in rb_iter_peek(): again: ... if (RB_WARN_ON(cpu_buffer, ++nr_loops > 10)) return NULL; I'm not sure what the best way is to fix this. I don't know if I should extend the loop threshhold, or if I should make the test more complex (ignore TIME_EXTEND events), or just get rid of this loop check completely. Note that if I implement a workaround for this, then I see another problem from rb_advance_iter(). I haven't tracked that one down yet. In general, it seems like the case of removing filtered events has not been working properly, and so some assumptions about buffer invariant conditions need to be revisited. Here's the patch for the simple fix: Compare correct pointer for checking if an event can be freed rather than left as discarded in the buffer. Signed-off-by: Tim Bird <tim.bird@am.sony.com> LKML-Reference: <4A25BE9E.5090909@am.sony.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-06-02function-graph: always initialize task ret_stackSteven Rostedt
On creating a new task while running the function graph tracer, if we fail to allocate the ret_stack, and then fail the fork, the code will free the parent ret_stack. This is because the child duplicated the parent and currently points to the parent's ret_stack. This patch always initializes the task's ret_stack to NULL. [ Impact: prevent crash of parent on low memory during fork ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-06-02function-graph: move initialization of new tasks up in forkSteven Rostedt
When the function graph tracer is enabled, all new tasks must allocate a ret_stack to place the return address of functions. This is because the function graph tracer will replace the real return address with a call to the tracing of the exit function. This initialization happens in fork, but it happens too late. If fork fails, then it will call free_task and that calls the freeing of this ret_stack. But before initialization happens, the new (failed) task points to its parents ret_stack. If a fork failure happens during the function trace, it would be catastrophic for the parent. Also, there's no need to call ftrace_graph_exit_task from fork, since it is called by free_task which fork calls on failure. [ Impact: prevent crash during failed fork running function graph tracer ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-06-02function-graph: add memory barriers for accessing task's ret_stackSteven Rostedt
The code that handles the tasks ret_stack allocation for every task assumes that only an interrupt can cause issues (even though interrupts are disabled). In reality, the code is allocating the ret_stack for tasks that may be running on other CPUs and there are not efficient memory barriers to handle this case. [ Impact: prevent crash due to using of uninitialized ret_stack variables ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-06-02function-graph: enable the stack after initialization of other variablesSteven Rostedt
The function graph tracer checks if the task_struct has ret_stack defined to know if it is OK or not to use it. The initialization is done for all tasks by one process, but the idle tasks use the same initialization used by new tasks. If an interrupt happens on an idle task that just had the ret_stack created, but before the rest of the initialization took place, then we can corrupt the return address of the functions. This patch moves the setting of the task_struct's ret_stack to after the other variables have been initialized. [ Impact: prevent kernel panic on idle task when starting function graph ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-06-02function-graph: only allocate init tasks if it was not already doneSteven Rostedt
When the function graph tracer is enabled, it calls the initialization needed for the init tasks that would be called on all created tasks. The problem is that this is called every time the function graph tracer is enabled, and the ret_stack is allocated for the idle tasks each time. Thus, the old ret_stack is lost and a memory leak is created. This is also dangerous because if an interrupt happened on another CPU with the init task and the ret_stack is replaced, we then lose all the return pointers for the interrupt, and a crash would take place. [ Impact: fix memory leak and possible crash due to race ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-06-01ftrace: do not profile functions when disabledSteven Rostedt
A race was found that if one were to enable and disable the function profiler repeatedly, then the system can panic. This was because a profiled function may be preempted just before disabling interrupts. While the profiler is disabled and then reenabled, the preempted function could start again, and access the hash as it is being initialized. This just adds a check in the irq disabled part to check if the profiler is enabled, and if it is not then it will just exit. When the system is disabled, the profile_enabled variable is cleared before calling the unregistering of the function profiler. This unregistering calls stop machine which also acts as a synchronize schedule. [ Impact: fix panic in enabling/disabling function profiler ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-06-01tracing: make trace pipe recognize latency format flagSteven Rostedt
The trace_pipe did not recognize the latency format flag and would produce different output than the trace file. The problem was partly due that the trace flags in the iterator was not set as well as the trace_pipe zeros out part of the iterator (including the flags) to be able to use the same routines as the trace file. trace_flags of the iterator should not cause any problems when not zeroed out by for trace_pipe. Reported-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-06-01tracing: add exports to use __print_symbolic and __print_flags from a moduleSteven Whitehouse
A patch to allow the use of __print_symbolic and __print_flags from a module. This allows the current GFS2 tracing patch to build. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com> LKML-Reference: <1243868015.29604.542.camel@localhost.localdomain> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-06-01tracing/events: introduce __dynamic_array()Li Zefan
__string() is limited: - it's a char array, but we may want to define array with other types - a source string should be available, but we may just know the string size We introduce __dynamic_array() to break those limitations, and __string() becomes a wrapper of it. As a side effect, now __get_str() can be used in TP_fast_assign but not only TP_print. Take XFS for example, we have the string length in the dirent, but the string itself is not NULL-terminated, so __dynamic_array() can be used: TRACE_EVENT(xfs_dir2, TP_PROTO(struct xfs_da_args *args), TP_ARGS(args), TP_STRUCT__entry( __field(int, namelen) __dynamic_array(char, name, args->namelen + 1) ... ), TP_fast_assign( char *name = __get_str(name); if (args->namelen) memcpy(name, args->name, args->namelen); name[args->namelen] = '\0'; __entry->namelen = args->namelen; ), TP_printk("name %.*s namelen %d", __entry->namelen ? __get_str(name) : NULL __entry->namelen) ); [ Impact: allow defining dynamic size arrays ] Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> LKML-Reference: <4A2384D2.3080403@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-06-01tracing: combine the default tracers into one configSteven Rostedt
Both event tracer and sched switch plugin are selected by default by all generic tracers. But if no generic tracer is enabled, their options appear. But ether one of them will select the other, thus it only makes sense to have the default tracers be selected by one option. [ Impact: clean up kconfig menu ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-06-01tracing: fix config options to not show when automatically selectedSteven Rostedt
There are two options that are selected by all tracers, but we want to have those options available when no tracer is selected. These are The event tracer and sched switch tracer. The are enabled by all tracers, but if a tracer is not selected we want the options to appear. All tracers including them select TRACING. Thus what we would like to do is: config EVENT_TRACER bool "prompt" depends on TRACING select TRACING But that gives us a bug in the kbuild system since we just created a circular dependency. We only want the prompt to show when TRACING is off. This patch adds GENERIC_TRACER that all tracers will select instead of TRACING. The two options (sched switch and event tracer) will select TRACING directly and depend on !GENERIC_TRACER. This solves the cicular dependency. [ Impact: hide options that are selected by default ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-06-01ftrace: add kernel command line function filteringSteven Rostedt
When using ftrace=function on the command line to trace functions on boot up, one can not filter out functions that are commonly called. This patch adds two new ftrace command line commands. ftrace_notrace=function-list ftrace_filter=function-list Where function-list is a comma separated list of functions to filter. The ftrace_notrace will make the functions listed not be included in the function tracing, and ftrace_filter will only trace the functions listed. These two act the same as the debugfs/tracing/set_ftrace_notrace and debugfs/tracing/set_ftrace_filter respectively. The simple glob expressions that are allowed by the filter files can also be used by the command line interface. ftrace_notrace=rcu*,*lock,*spin* Will not trace any function that starts with rcu, ends with lock, or has the word spin in it. Note, if the self tests are enabled, they may interfere with the filtering set by the command lines. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-06-02tracing/stat: remove unappropriate safe walk on listFrederic Weisbecker
register_stat_tracer() uses list_for_each_entry_safe to check whether a tracer is already present in the list. But we don't delete anything from the list here, so we don't need the safe version [ Impact: cleanup list use is stat tracing ] Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-06-02tracing/stat: do some cleanupsLi Zefan
- remove duplicate code in stat_seq_init() - update comments to reflect the change from stat list to stat rbtree [ Impact: clean up ] Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-06-02tracing/stat: remember to free root nodeLi Zefan
When closing a trace_stat file, we destroy the rbtree constructed during file open, but there is memory leak that the root node is not freed. [ Impact: fix memory leak when closing a trace_stat file ] Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-06-02tracing/stat: change dummpy_cmp() to return -1Li Zefan
Currently the output of trace_stat/workqueues is totally reversed: # cat /debug/tracing/trace_stat/workqueues ... 1 17 17 210 37 `-blk_unplug_work+0x0/0x57 1 3779 3779 181 11 |-cfq_kick_queue+0x0/0x2f 1 3796 3796 kblockd/1:120 ... The correct output should be: 1 3796 3796 kblockd/1:120 1 3779 3779 181 11 |-cfq_kick_queue+0x0/0x2f 1 17 17 210 37 `-blk_unplug_work+0x0/0x57 It's caused by "tracing/stat: replace linked list by an rbtree for sorting" (53059c9b67a62a3dc8c80204d3da42b9267ea5a0). dummpy_cmp() should return -1, so rb_node will always be inserted as right-most node in the rbtree, thus we sort the output in ascending order. [ Impact: fix the output of trace_stat/workqueues ] Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-06-02tracing/stat: replace linked list by an rbtree for sortingFrederic Weisbecker
When the stat tracing framework prepares the entries from a tracer to output them to the user, it starts by computing a linear sort through a linked list to give the entries ordered by relevance to the user. This is quite ugly and causes a small latency when we begin to read the file. This patch changes that by turning the linked list into a red-black tree. Athough the whole iteration using the start and next tracer callbacks while opening the file remain the same, it is now much more fast and scalable. The rbtree guarantees O(log(n)) insertions whereas a linked list with linear sorting brought us a O(n) despair. Now the (visible) latency has disapeared. [ Impact: kill the latency while starting to read a stat tracer file ] Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-06-02tracing/stat: replace trace_stat_session by stat_sessionFrederic Weisbecker
The "trace" prefix in struct trace_stat_session type is annoying while reading the trace_stat.c file. It makes the lines longer, and is not that much useful to explain the sense of this type. Just keep "struct stat_session" for this type. [ Impact: make the code a bit more readable ] Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-06-02trace_workqueue: remove blank line between each cpuZhaolei
The blankline between each cpu's workqueue stat is not necessary, because the cpu number is enough to part them by eye. Old style also caused a blankline below headline, and made code complex by using lock, disableirq and get cpu var. Old style: # CPU INSERTED EXECUTED NAME # | | | | 0 8644 8644 events/0 0 0 0 cpuset ... 0 1 1 kdmflush 1 35365 35365 events/1 ... New style: # CPU INSERTED EXECUTED NAME # | | | | 0 8644 8644 events/0 0 0 0 cpuset ... 0 1 1 kdmflush 1 35365 35365 events/1 ... [ Impact: provide more readable code ] Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Tom Zanussi <tzanussi@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-06-02trace_workqueue: remove cpu_workqueue_stats->first_entryZhaolei
cpu_workqueue_stats->first_entry is useless because we can retrieve the header of a cpu workqueue using: if (&cpu_workqueue_stats->list == workqueue_cpu_stat(cpu)->list.next) [ Impact: cleanup ] Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Tom Zanussi <tzanussi@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>