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2009-12-30tracing: Fix sign fields in ftrace_define_fields_##call()Lai Jiangshan
Add is_signed_type() call to trace_define_field() in ftrace macros. The code previously just passed in 0 (false), disregarding whether or not the field was actually a signed type. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> LKML-Reference: <4B273D3A.6020007@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-12-30tracing/kprobe: Show sign of fields in trace_kprobe format filesLai Jiangshan
The format files of trace_kprobe do not show the sign of the fields. The other format files show the field signed type of the fields and this patch makes the trace_kprobe formats consistent with the others. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> LKML-Reference: <4B273D27.5040009@cn.fujitsu.com> Acked-by: Masami Hiramatsu <mhiramat@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-12-30ksym_tracer: Remove trace_statLi Zefan
trace_stat is problematic. Don't use it, use seqfile instead. This fixes a race that reading the stat file is not protected by any lock, which can lead to use after free. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: K.Prasad <prasad@linux.vnet.ibm.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <4B3AF203.40200@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-30ksym_tracer: Fix race when incrementing countLi Zefan
We are under rcu read section but not holding the write lock, so count++ is not atomic. Use atomic64_t instead. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: K.Prasad <prasad@linux.vnet.ibm.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <4B3AF1EC.9010608@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-30ksym_tracer: Fix to allow writing newline to ksym_trace_filterLi Zefan
It used to work, but now doesn't: # echo > ksym_filter bash: echo: write error: Invalid argument It's caused by d954fbf0ff6b5fdfb32350e85a2f15d3db976506 ("tracing: Fix wrong usage of strstrip in trace_ksyms"). Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: K.Prasad <prasad@linux.vnet.ibm.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <4B3AF1D7.5040400@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-30ksym_tracer: Fix to make the tracer workLi Zefan
ksym tracer doesn't work: # echo tasklist_lock:rw- > ksym_trace_filter -bash: echo: write error: No such device It's because we pass to perf_event_create_kernel_counter() a cpu number which is not present. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: K.Prasad <prasad@linux.vnet.ibm.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <4B3AF19E.1010201@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-28tracing: Kconfig spelling fixes and cleanupsRandy Dunlap
Fix filename reference (ftrace-implementation.txt -> ftrace-design.txt). Fix spelling, punctuation, grammar. Fix help text indentation and line lengths to reduce need for horizontal scrolling or larger window sizes. Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <20091221120117.3fb49cdc.randy.dunlap@oracle.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-21tracing: Fix setting tracer specific optionsSteven Rostedt
The function __set_tracer_option() takes as its last parameter a "neg" value. If set it should negate the value of the option. The trace_options_write() passed the value written to the file which is what the new value needs to be set as. But since this is not the negative, it never sets the value. Reported-by: Peter Zijlstra <peterz@infradead.org> Cc: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-12-15tracing: Fix return of trace_dump_stack()Steven Rostedt
The trace_dump_stack() returned a value for a void function. Also, added the missing stub for trace_dump_stack() when tracing is not configured. Reported-by: Ingo Molnar <mingo@elte.hu> LKML-Reference: <20091214162713.GA31060@elte.hu> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-14Merge branch 'tip/tracing/core' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into tracing/urgent
2009-12-14Merge branch 'linus' into tracing/urgentIngo Molnar
Conflicts: kernel/trace/trace_kprobe.c Merge reason: resolve the conflict. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-13ksym_tracer: Fix bad castLi Zefan
Fix this warning: kernel/trace/trace_ksym.c: In function 'ksym_trace_filter_read': kernel/trace/trace_ksym.c:239: warning: cast to pointer from integer of different size Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: "K.Prasad" <prasad@linux.vnet.ibm.com> LKML-Reference: <4B1DC578.9020909@cn.fujitsu.com> [remove the strstrip fix as tglx already fixed that] Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-12-13tracing/power: Remove two exportsLi Zefan
trace_power_start and trace_power_end are used in arch/x86/kernel/power.c, and this file can't be compiled as a module, so these two tracepoints don't need to be exported. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <4B1DC55F.7060305@cn.fujitsu.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-12-13tracing: Change event->profile_count to be int typeLi Zefan
Like total_profile_count, struct ftrace_event_call::profile_count is protected by event_mutex, so it doesn't need to be atomic_t. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Jason Baron <jbaron@redhat.com> Cc: Masami Hiramatsu <mhiramat@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <4B1DC549.5010705@cn.fujitsu.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-12-13tracing: Simplify trace_option_write()Li Zefan
- remove duplicate code inside trace_options_write() - extract duplicate code in trace_options_write() and set_tracer_option() Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <4B1DC532.9010802@cn.fujitsu.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-12-13tracing: Remove useless trace optionLi Zefan
Since commit 4d9493c90f8e6e1b164aede3814010a290161abb ("ftrace: remove add-hoc code"), option "sched-tree" has become useless. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <4B1DC50A.7040402@cn.fujitsu.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-12-13tracing: Use seq file for trace_clockLi Zefan
The buffer for the output is as small as 64 bytes, so it'll overflow if we add more clock type. Use seq file instead. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <4B1DC4FB.5030407@cn.fujitsu.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-12-13tracing: Use seq file for trace_optionsLi Zefan
Code simplification for reading trace_options. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> LKML-reference: <4B1DC4EF.3090106@cn.fujitsu.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-12-13function-graph: Allow writing the same val to set_graph_functionLi Zefan
# echo 'do_open' > set_graph_function # echo 'do_open' >> set_graph_function bash: echo: write error: Invalid argument Make it valid to write the same value to set_graph_function, which is consistent with set_ftrace_filter interface. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> LKML-reference: <4B1DC4E1.1060303@cn.fujitsu.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-12-13ftrace: Call trace_parser_clear() properlyLi Zefan
I found a weird behavior: # echo 'fuse:*' > set_ftrace_filter bash: echo: write error: Invalid argument # cat set_ftrace_filter fuse_dev_fasync fuse_dev_poll fuse_copy_do We should call trace_parser_clear() no matter ftrace_process_regex() returns 0 or -errno, otherwise we will actually take the unaccepted records from ftrace_regex_release(). Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <4B1DC4D2.3000406@cn.fujitsu.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-12-13ftrace: Return EINVAL when writing invalid val to set_ftrace_filterLi Zefan
Currently it doesn't warn user on invald value: # echo nonexist_symbol > set_ftrace_filter or: # echo 'nonexist_symbol:mod:fuse' > set_ftrace_filter Better make it return failure. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <4B1DC4BF.2070003@cn.fujitsu.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-12-13tracing: Move a printk out of ftrace_raw_reg_event_foo()Li Zefan
Move the printk from each ftrace_raw_reg_event_foo() to its caller ftrace_event_enable_disable(). This avoids each regfunc trace event callbacks to handle a same error report that can be carried from the caller. See how much space this saves: text data bss dec hex filename 5345151 1961864 7103260 14410275 dbe223 vmlinux.o.old 5331487 1961864 7103260 14396611 dbacc3 vmlinux.o Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Jason Baron <jbaron@redhat.com> LKML-Reference: <4B1DC4AC.802@cn.fujitsu.com> [start cmdline record before calling regfunc to avoid lost window of pid to comm resolution] Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-12-13tracing: Pull up calls to trace_define_common_fields()Li Zefan
Call trace_define_common_fields() in event_create_dir() only. This avoids trace events to handle it from their define_fields callbacks and shrinks the kernel code size: text data bss dec hex filename 5346802 1961864 7103260 14411926 dbe896 vmlinux.o.old 5345151 1961864 7103260 14410275 dbe223 vmlinux.o Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Jason Baron <jbaron@redhat.com> Cc: Masami Hiramatsu <mhiramat@redhat.com> LKML-Reference: <4B1DC49C.8000107@cn.fujitsu.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-12-13tracing: Extract duplicate ftrace_raw_init_event_foo()Li Zefan
Use a generic trace_event_raw_init() function for all event's raw_init callbacks (but kprobes) instead of defining the same version for each of these. This shrinks the kernel code: text data bss dec hex filename 5355293 1961928 7103260 14420481 dc0a01 vmlinux.o.old 5346802 1961864 7103260 14411926 dbe896 vmlinux.o raw_init can't be removed, because ftrace events and kprobe events use different raw_init callbacks. Though it's possible to totally remove raw_init, I choose to leave it as it is for now. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Jason Baron <jbaron@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> LKML-Reference: <4B1DC48C.7080603@cn.fujitsu.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-12-12Merge branch 'sched-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (21 commits) sched: Remove forced2_migrations stats sched: Fix memory leak in two error corner cases sched: Fix build warning in get_update_sysctl_factor() sched: Update normalized values on user updates via proc sched: Make tunable scaling style configurable sched: Fix missing sched tunable recalculation on cpu add/remove sched: Fix task priority bug sched: cgroup: Implement different treatment for idle shares sched: Remove unnecessary RCU exclusion sched: Discard some old bits sched: Clean up check_preempt_wakeup() sched: Move update_curr() in check_preempt_wakeup() to avoid redundant call sched: Sanitize fork() handling sched: Clean up ttwu() rq locking sched: Remove rq->clock coupling from set_task_cpu() sched: Consolidate select_task_rq() callers sched: Remove sysctl.sched_features sched: Protect sched_rr_get_param() access to task->sched_class sched: Protect task->cpus_allowed access in sched_getaffinity() sched: Fix balance vs hotplug race ... Fixed up conflicts in kernel/sysctl.c (due to sysctl cleanup)
2009-12-11Merge branch 'timers-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: itimer: Fix the itimer trace print format hrtimer: move timer stats helper functions to hrtimer.c hrtimer: Tune hrtimer_interrupt hang logic
2009-12-11Merge branch 'core-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: lockdep: Avoid out of bounds array reference in save_trace() futex: Take mmap_sem for get_user_pages in fault_in_user_writeable lockstat: Add usage info to Documentation/lockstat.txt lockstat: Fix min, max times in /proc/lock_stats
2009-12-11Merge branch 'tracing-fixes-for-linus' of ↵Linus Torvalds
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: tracing: Remove comparing of NULL to va_list in trace_array_vprintk() tracing: Fix function graph trace_pipe to properly display failed entries tracing: Add full state to trace_seq tracing: Buffer the output of seq_file in case of filled buffer tracing: Only call pipe_close if pipe_close is defined tracing: Add pipe_close interface
2009-12-11Merge branch 'perf-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (57 commits) x86, perf events: Check if we have APIC enabled perf_event: Fix variable initialization in other codepaths perf kmem: Fix unused argument build warning perf symbols: perf_header__read_build_ids() offset'n'size should be u64 perf symbols: dsos__read_build_ids() should read both user and kernel buildids perf tools: Align long options which have no short forms perf kmem: Show usage if no option is specified sched: Mark sched_clock() as notrace perf sched: Add max delay time snapshot perf tools: Correct size given to memset perf_event: Fix perf_swevent_hrtimer() variable initialization perf sched: Fix for getting task's execution time tracing/kprobes: Fix field creation's bad error handling perf_event: Cleanup for cpu_clock_perf_event_update() perf_event: Allocate children's perf_event_ctxp at the right time perf_event: Clean up __perf_event_init_context() hw-breakpoints: Modify breakpoints without unregistering them perf probe: Update perf-probe document perf probe: Support --del option trace-kprobe: Support delete probe syntax ...
2009-12-11Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6: (58 commits) tty: split the lock up a bit further tty: Move the leader test in disassociate tty: Push the bkl down a bit in the hangup code tty: Push the lock down further into the ldisc code tty: push the BKL down into the handlers a bit tty: moxa: split open lock tty: moxa: Kill the use of lock_kernel tty: moxa: Fix modem op locking tty: moxa: Kill off the throttle method tty: moxa: Locking clean up tty: moxa: rework the locking a bit tty: moxa: Use more tty_port ops tty: isicom: fix deadlock on shutdown tty: mxser: Use the new locking rules to fix setserial properly tty: mxser: use the tty_port_open method tty: isicom: sort out the board init logic tty: isicom: switch to the new tty_port_open helper tty: tty_port: Add a kref object to the tty port tty: istallion: tty port open/close methods tty: stallion: Convert to the tty_port_open/close methods ...
2009-12-11Merge branch 'for_linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb * 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb: kgdb: Always process the whole breakpoint list on activate or deactivate kgdb: continue and warn on signal passing from gdb kgdb,x86: do not set kgdb_single_step on x86 kgdb: allow for cpu switch when single stepping kgdb,i386: Fix corner case access to ss with NMI watch dog exception kgdb: Replace strstr() by strchr() for single-character needles kgdbts: Read buffer overflow kgdb: Read buffer overflow kgdb,x86: remove redundant test
2009-12-11tty: Move the leader test in disassociateAlan Cox
There are two call points, both want to check that tty->signal->leader is set. Move the test into disassociate_ctty() as that will make locking changes easier in a bit Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-12-11Merge branch 'linux-next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6 * 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6: (109 commits) PCI: fix coding style issue in pci_save_state() PCI: add pci_request_acs PCI: fix BUG_ON triggered by logical PCIe root port removal PCI: remove ifdefed pci_cleanup_aer_correct_error_status PCI: unconditionally clear AER uncorr status register during cleanup x86/PCI: claim SR-IOV BARs in pcibios_allocate_resource PCI: portdrv: remove redundant definitions PCI: portdrv: remove unnecessary struct pcie_port_data PCI: portdrv: minor cleanup for pcie_port_device_register PCI: portdrv: add missing irq cleanup PCI: portdrv: enable device before irq initialization PCI: portdrv: cleanup service irqs initialization PCI: portdrv: check capabilities first PCI: portdrv: move PME capability check PCI: portdrv: remove redundant pcie type calculation PCI: portdrv: cleanup pcie_device registration PCI: portdrv: remove redundant pcie_port_device_probe PCI: Always set prefetchable base/limit upper32 registers PCI: read-modify-write the pcie device control register when initiating pcie flr PCI: show dma_mask bits in /sys ... Fixed up conflicts in: arch/x86/kernel/amd_iommu_init.c drivers/pci/dmar.c drivers/pci/hotplug/acpiphp_glue.c
2009-12-11tracing: Add stack trace to irqsoff tracerSteven Rostedt
The irqsoff and friends tracers help in finding causes of latency in the kernel. The also work with the function tracer to show what was happening when interrupts or preemption are disabled. But the function tracer has a bit of an overhead and can cause exagerated readings. Currently, when tracing with /proc/sys/kernel/ftrace_enabled = 0, where the function tracer is disabled, the information that is provided can end up being useless. For example, a 2 and a half millisecond latency only showed: # tracer: preemptirqsoff # # preemptirqsoff latency trace v1.1.5 on 2.6.32 # -------------------------------------------------------------------- # latency: 2463 us, #4/4, CPU#2 | (M:preempt VP:0, KP:0, SP:0 HP:0 #P:4) # ----------------- # | task: -4242 (uid:0 nice:0 policy:0 rt_prio:0) # ----------------- # => started at: _spin_lock_irqsave # => ended at: remove_wait_queue # # # _------=> CPU# # / _-----=> irqs-off # | / _----=> need-resched # || / _---=> hardirq/softirq # ||| / _--=> preempt-depth # |||| /_--=> lock-depth # |||||/ delay # cmd pid |||||| time | caller # \ / |||||| \ | / hackbenc-4242 2d.... 0us!: trace_hardirqs_off <-_spin_lock_irqsave hackbenc-4242 2...1. 2463us+: _spin_unlock_irqrestore <-remove_wait_queue hackbenc-4242 2...1. 2466us : trace_preempt_on <-remove_wait_queue The above lets us know that hackbench with pid 2463 grabbed a spin lock somewhere and enabled preemption at remove_wait_queue. This helps a little but where this actually happened is not informative. This patch adds the stack dump to the end of the irqsoff tracer. This provides the following output: hackbenc-4242 2d.... 0us!: trace_hardirqs_off <-_spin_lock_irqsave hackbenc-4242 2...1. 2463us+: _spin_unlock_irqrestore <-remove_wait_queue hackbenc-4242 2...1. 2466us : trace_preempt_on <-remove_wait_queue hackbenc-4242 2...1. 2467us : <stack trace> => sub_preempt_count => _spin_unlock_irqrestore => remove_wait_queue => free_poll_entry => poll_freewait => do_sys_poll => sys_poll => system_call_fastpath Now we see that the culprit of this latency was the free_poll_entry code. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-12-11tracing: Add trace_dump_stack()Steven Rostedt
I've been asked a few times about how to find out what is calling some location in the kernel. One way is to use dynamic function tracing and implement the func_stack_trace. But this only finds out who is calling a particular function. It does not tell you who is calling that function and entering a specific if conditional. I have myself implemented a quick version of trace_dump_stack() for this purpose a few times, and just needed it now. This is when I realized that this would be a good tool to have in the kernel like trace_printk(). Using trace_dump_stack() is similar to dump_stack() except that it writes to the trace buffer instead and can be used in critical locations. For example: @@ -5485,8 +5485,12 @@ need_resched_nonpreemptible: if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) { if (unlikely(signal_pending_state(prev->state, prev))) prev->state = TASK_RUNNING; - else + else { deactivate_task(rq, prev, 1); + trace_printk("Deactivating task %s:%d\n", + prev->comm, prev->pid); + trace_dump_stack(); + } switch_count = &prev->nvcsw; } Produces: <...>-3249 [001] 296.105269: schedule: Deactivating task ntpd:3249 <...>-3249 [001] 296.105270: <stack trace> => schedule => schedule_hrtimeout_range => poll_schedule_timeout => do_select => core_sys_select => sys_select => system_call_fastpath Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-12-11kgdb: Always process the whole breakpoint list on activate or deactivateJason Wessel
This patch fixes 2 edge cases in using kgdb in conjunction with gdb. 1) kgdb_deactivate_sw_breakpoints() should process the entire array of breakpoints. The failure to do so results in breakpoints that you cannot remove, because a break point can only be removed if its state flag is set to BP_SET. The easy way to duplicate this problem is to plant a break point in a kernel module and then unload the kernel module. 2) kgdb_activate_sw_breakpoints() should process the entire array of breakpoints. The failure to do so results in missed breakpoints when a breakpoint cannot be activated. Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2009-12-11kgdb: continue and warn on signal passing from gdbJason Wessel
On some architectures for the segv trap, gdb wants to pass the signal back on continue. For kgdb this is not the default behavior, because it can cause the kernel to crash if you arbitrarily pass back a exception outside of kgdb. Instead of causing instability, pass a message back to gdb about the supported kgdb signal passing and execute a standard kgdb continue operation. Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2009-12-11kgdb: allow for cpu switch when single steppingJason Wessel
The kgdb core should not assume that a single step operation of a kernel thread will complete on the same CPU. The single step flag is set at the "thread" level and it is possible in a multi cpu system that a kernel thread can get scheduled on another cpu the next time it is run. As a further safety net in case a slave cpu is hung, the debug master cpu will try 100 times before giving up and assuming control of the slave cpus is no longer possible. It is more useful to be able to get some information out of kgdb instead of spinning forever. Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2009-12-11kgdb: Read buffer overflowJason Wessel
Roel Kluin reported an error found with Parfait. Where we want to ensure that that kgdb_info[-1] never gets accessed. Also check to ensure any negative tid does not exceed the size of the shadow CPU array, else report critical debug context because it is an internal kgdb failure. Reported-by: Roel Kluin <roel.kluin@gmail.com> Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2009-12-10ring-buffer: Move resize integrity check under reader lockSteven Rostedt
While using an application that does splice on the ftrace ring buffer at start up, I triggered an integrity check failure. Looking into this, I discovered that resizing the buffer performs an integrity check after the buffer is resized. This check unfortunately is preformed after it releases the reader lock. If a reader is reading the buffer it may cause the integrity check to trigger a false failure. This patch simply moves the integrity checker under the protection of the ring buffer reader lock. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-12-10ring-buffer: Use sync sched protection on ring buffer resizingSteven Rostedt
There was a comment in the ring buffer code that says the calling layers should prevent tracing or reading of the ring buffer while resizing. I have discovered that the tracers do not honor this arrangement. This patch moves the disabling and synchronizing the ring buffer to a higher layer during resizing. This guarantees that no writes are occurring while the resize takes place. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-12-11tracing: Fix wrong usage of strstrip in trace_ksymsThomas Gleixner
strstrip returns a pointer to the first non space character, but the code in parse_ksym_trace_str() ignores that. strstrip is now must_check and therefor we get the correct warning: kernel/trace/trace_ksym.c:294: warning: ignoring return value of ‘strstrip’, declared with attribute warn_unused_result We are really not interested in leading whitespace here. Fix that and cleanup the dozen kfree() exit pathes. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Cc: Steven Rostedt <rostedt@goodmis.org>
2009-12-10sched: Remove forced2_migrations statsIngo Molnar
This build warning: kernel/sched.c: In function 'set_task_cpu': kernel/sched.c:2070: warning: unused variable 'old_rq' Made me realize that the forced2_migrations stat looks pretty pointless (and a misnomer) - remove it. Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-10Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wqLinus Torvalds
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: workqueue: Add debugobjects support
2009-12-10perf_event: Fix variable initialization in other codepathsXiao Guangrong
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <4B20BAA6.7010609@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-10sched: Fix memory leak in two error corner casesPhil Carmody
If the second in each of these pairs of allocations fails, then the first one will not be freed in the error route out. Found by a static code analysis tool. Signed-off-by: Phil Carmody <ext-phil.2.carmody@nokia.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1260448177-28448-1-git-send-email-ext-phil.2.carmody@nokia.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-10hrtimer: move timer stats helper functions to hrtimer.cHeiko Carstens
There is no reason to make timer_stats_hrtimer_set_start_info and friends visible to the rest of the kernel. So move all of them to hrtimer.c. Also make timer_stats_hrtimer_set_start_info a static inline function so it gets inlined and we avoid another function call. Based on a patch by Thomas Gleixner. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> LKML-Reference: <20091210095629.GC4144@osiris.boeblingen.de.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-12-10hrtimer: Tune hrtimer_interrupt hang logicThomas Gleixner
The hrtimer_interrupt hang logic adjusts min_delta_ns based on the execution time of the hrtimer callbacks. This is error-prone for virtual machines, where a guest vcpu can be scheduled out during the execution of the callbacks (and the callbacks themselves can do operations that translate to blocking operations in the hypervisor), which in can lead to large min_delta_ns rendering the system unusable. Replace the current heuristics with something more reliable. Allow the interrupt code to try 3 times to catch up with the lost time. If that fails use the total time spent in the interrupt handler to defer the next timer interrupt so the system can catch up with other things which got delayed. Limit that deferment to 100ms. The retry events and the maximum time spent in the interrupt handler are recorded and exposed via /proc/timer_list Inspired by a patch from Marcelo. Reported-by: Michael Tokarev <mjt@tls.msk.ru> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Marcelo Tosatti <mtosatti@redhat.com> Cc: kvm@vger.kernel.org
2009-12-10sched: Fix build warning in get_update_sysctl_factor()Mike Galbraith
Signed-off-by: Mike Galbraith <efault@gmx.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu> LKML-Reference: <new-submission>
2009-12-10lockdep: Avoid out of bounds array reference in save_trace()Luck, Tony
ia64 found this the hard way (because we currently have a stub for save_stack_trace() that does nothing). But it would be a good idea to be cautious in case a real save_stack_trace() bailed out with an error before it set trace->nr_entries. Signed-off-by: Tony Luck <tony.luck@intel.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: luming.yu@intel.com LKML-Reference: <4b2024d085302c2a2@agluck-desktop.sc.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>