summaryrefslogtreecommitdiff
path: root/kernel
AgeCommit message (Collapse)AuthorFilesLines
2009-09-13tracing/profile: fix profile_disable vs module_unloadLi Zefan1-1/+4
If the correspoding module is unloaded before ftrace_profile_disable() is called, event->profile_disable() won't be called, which can cause oops: # insmod trace-events-sample.ko # perf record -f -a -e sample:foo_bar sleep 3 & # sleep 1 # rmmod trace_events_sample # insmod trace-events-sample.ko OOPS! Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> LKML-Reference: <4A9214E3.2070807@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-09-13tracing: do not update tracing_max_latency when tracer is stoppedCarsten Emde4-4/+14
The state of the function pair tracing_stop()/tracing_start() is correctly considered when tracer data are updated. However, the global and externally accessible variable tracing_max_latency is always updated - even when tracing is stopped. The update should only occur, if tracing was not stopped. Signed-off-by: Carsten Emde <C.Emde@osadl.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-09-13tracing: remove unused local variables in tracer probe functionsCarsten Emde2-21/+1
When the nsecs_to_usecs() conversion in probe_wakeup_sched_switch() and check_critical_timing() was moved to a later stage in order to avoid unnecessary computing, it was overlooked to remove the original variables, assignments and comments.. Signed-off-by: Carsten Emde <C.Emde@osadl.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-09-12Merge branch 'tracing-core-for-linus' of ↵Linus Torvalds28-1097/+2434
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'tracing-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (105 commits) ring-buffer: only enable ring_buffer_swap_cpu when needed ring-buffer: check for swapped buffers in start of committing tracing: report error in trace if we fail to swap latency buffer tracing: add trace_array_printk for internal tracers to use tracing: pass around ring buffer instead of tracer tracing: make tracing_reset safe for external use tracing: use timestamp to determine start of latency traces tracing: Remove mentioning of legacy latency_trace file from documentation tracing/filters: Defer pred allocation, fix memory leak tracing: remove users of tracing_reset tracing: disable buffers and synchronize_sched before resetting tracing: disable update max tracer while reading trace tracing: print out start and stop in latency traces ring-buffer: disable all cpu buffers when one finds a problem ring-buffer: do not count discarded events ring-buffer: remove ring_buffer_event_discard ring-buffer: fix ring_buffer_read crossing pages ring-buffer: remove unnecessary cpu_relax ring-buffer: do not swap buffers during a commit ring-buffer: do not reset while in a commit ...
2009-09-12Merge branch 'sched-core-for-linus' of ↵Linus Torvalds9-485/+826
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: (64 commits) sched: Fix sched::sched_stat_wait tracepoint field sched: Disable NEW_FAIR_SLEEPERS for now sched: Keep kthreads at default priority sched: Re-tune the scheduler latency defaults to decrease worst-case latencies sched: Turn off child_runs_first sched: Ensure that a child can't gain time over it's parent after fork() sched: enable SD_WAKE_IDLE sched: Deal with low-load in wake_affine() sched: Remove short cut from select_task_rq_fair() sched: Turn on SD_BALANCE_NEWIDLE sched: Clean up topology.h sched: Fix dynamic power-balancing crash sched: Remove reciprocal for cpu_power sched: Try to deal with low capacity, fix update_sd_power_savings_stats() sched: Try to deal with low capacity sched: Scale down cpu_power due to RT tasks sched: Implement dynamic cpu_power sched: Add smt_gain sched: Update the cpu_power sum during load-balance sched: Add SD_PREFER_SIBLING ...
2009-09-12Merge branch 'perfcounters-core-for-linus' of ↵Linus Torvalds1-36/+137
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'perfcounters-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (60 commits) perf tools: Avoid unnecessary work in directory lookups perf stat: Clean up statistics calculations a bit more perf stat: More advanced variance computation perf stat: Use stddev_mean in stead of stddev perf stat: Remove the limit on repeat perf stat: Change noise calculation to use stddev x86, perf_counter, bts: Do not allow kernel BTS tracing for now x86, perf_counter, bts: Correct pointer-to-u64 casts x86, perf_counter, bts: Fail if BTS is not available perf_counter: Fix output-sharing error path perf trace: Fix read_string() perf trace: Print out in nanoseconds perf tools: Seek to the end of the header area perf trace: Fix parsing of perf.data perf trace: Sample timestamps as well perf_counter: Introduce new (non-)paranoia level to allow raw tracepoint access perf trace: Sample the CPU too perf tools: Work around strict aliasing related warnings perf tools: Clean up warnings list in the Makefile perf tools: Complete support for dynamic strings ...
2009-09-12Merge branch 'irq-threaded-for-linus' of ↵Linus Torvalds3-9/+180
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'irq-threaded-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: genirq: Do not mask oneshot edge type interrupts genirq: Support nested threaded irq handling genirq: Add buslock support genirq: Add oneshot support
2009-09-12Merge branch 'irq-core-for-linus' of ↵Linus Torvalds4-8/+9
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: pci/intr_remapping: Allocate irq_iommu on node irq: Add irq_node() primitive irq: Make sure irq_desc for legacy irq get correct node setting genirq: Add prototype for handle_nested_irq() irq: Remove superfluous NULL pointer check in check_irq_resend() irq: Clean up by removing irqfixup MODULE_PARM_DESC() genirq: Fix comment describing suspend_device_irqs() genirq: Remove obsolete defines and typedefs
2009-09-12Merge branch 'core-rcu-for-linus' of ↵Linus Torvalds15-2927/+1293
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (28 commits) rcu: Move end of special early-boot RCU operation earlier rcu: Changes from reviews: avoid casts, fix/add warnings, improve comments rcu: Create rcutree plugins to handle hotplug CPU for multi-level trees rcu: Remove lockdep annotations from RCU's _notrace() API members rcu: Add #ifdef to suppress __rcu_offline_cpu() warning in !HOTPLUG_CPU builds rcu: Add CPU-offline processing for single-node configurations rcu: Add "notrace" to RCU function headers used by ftrace rcu: Remove CONFIG_PREEMPT_RCU rcu: Merge preemptable-RCU functionality into hierarchical RCU rcu: Simplify rcu_pending()/rcu_check_callbacks() API rcu: Use debugfs_remove_recursive() simplify code. rcu: Merge per-RCU-flavor initialization into pre-existing macro rcu: Fix online/offline indication for rcudata.csv trace file rcu: Consolidate sparse and lockdep declarations in include/linux/rcupdate.h rcu: Renamings to increase RCU clarity rcu: Move private definitions from include/linux/rcutree.h to kernel/rcutree.h rcu: Expunge lingering references to CONFIG_CLASSIC_RCU, optimize on !SMP rcu: Delay rcu_barrier() wait until beginning of next CPU-hotunplug operation. rcu: Fix typo in rcu_irq_exit() comment header rcu: Make rcupreempt_trace.c look at offline CPUs ...
2009-09-12Merge branch 'core-printk-for-linus' of ↵Linus Torvalds1-57/+118
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-printk-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: printk: Fix "printk: Enable the use of more than one CON_BOOT (early console)" printk: Restore previous console_loglevel when re-enabling logging printk: Ensure that "console enabled" messages are printed on the console printk: Enable the use of more than one CON_BOOT (early console)
2009-09-12Merge branch 'core-locking-for-linus' of ↵Linus Torvalds5-506/+648
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (32 commits) locking, m68k/asm-offsets: Rename signal defines locking: Inline spinlock code for all locking variants on s390 locking: Simplify spinlock inlining locking: Allow arch-inlined spinlocks locking: Move spinlock function bodies to header file locking, m68k: Calculate thread_info offset with asm offset locking, m68k/asm-offsets: Rename pt_regs offset defines locking, sparc: Rename __spin_try_lock() and friends locking, powerpc: Rename __spin_try_lock() and friends lockdep: Remove recursion stattistics lockdep: Simplify lock_stat seqfile code lockdep: Simplify lockdep_chains seqfile code lockdep: Simplify lockdep seqfile code lockdep: Fix missing entries in /proc/lock_chains lockdep: Fix missing entry in /proc/lock_stat lockdep: Fix memory usage info of BFS lockdep: Reintroduce generation count to make BFS faster lockdep: Deal with many similar locks lockdep: Introduce lockdep_assert_held() lockdep: Fix style nits ...
2009-09-12Merge branch 'core-futexes-for-linus' of ↵Linus Torvalds1-17/+30
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-futexes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: futex: Detect mismatched requeue targets futex: Correct futex_wait_requeue_pi() commentary
2009-09-12Merge branch 'core-debug-for-linus' of ↵Linus Torvalds1-1/+6
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: debug lockups: Improve lockup detection, fix generic arch fallback debug lockups: Improve lockup detection
2009-09-12Merge branch 'core-cleanups-for-linus' of ↵Linus Torvalds1-1/+6
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: workqueues: Improve schedule_work() documentation
2009-09-11tracing: trace parser support for function and graphjolsa@redhat.com1-110/+40
Convert the writing to 'set_graph_function', 'set_ftrace_filter' and 'set_ftrace_notrace' to use the generic trace_parser 'trace_get_user' function. Removed FTRACE_ITER_CONT flag, since it's not needed after this change. Minor fix in set_graph_function display - g_show function. Signed-off-by: Jiri Olsa <jolsa@redhat.com> LKML-Reference: <1252682969-3366-4-git-send-email-jolsa@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-09-11tracing: trace parser support for set_eventjolsa@redhat.com1-47/+13
Convert the parsing of the file 'set_event' to use the generic trace_praser 'trace_get_user' function. Signed-off-by: Jiri Olsa <jolsa@redhat.com> LKML-Reference: <1252682969-3366-3-git-send-email-jolsa@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-09-11tracing: create generic trace parserjolsa@redhat.com2-0/+141
Create a "trace_parser" that can parse the user space input for separate words. struct trace_parser is the descriptor. Generic "trace_get_user" function that can be a helper to read multiple words passed in by user space. Signed-off-by: Jiri Olsa <jolsa@redhat.com> LKML-Reference: <1252682969-3366-2-git-send-email-jolsa@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-09-11tracing: consolidate code between trace_output.c and trace_function_graph.cSteven Rostedt3-30/+28
Both trace_output.c and trace_function_graph.c do basically the same thing to handle the printing of the latency-format. This patch moves the code into one function that both can use. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-09-11clocksource: Resolve cpu hotplug dead lock with TSC unstable, fix crashMartin Schwidefsky1-2/+3
The watchdog timer is started after the watchdog clocksource and at least one watched clocksource have been registered. The clocksource work element watchdog_work is initialized just before the clocksource timer is started. This is too late for the clocksource_mark_unstable call from native_cpu_up. To fix this use a static initializer for watchdog_work. This resolves a boot crash reported by multiple people. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: John Stultz <johnstul@us.ibm.com> LKML-Reference: <20090911153305.3fe9a361@skybase> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-11tracing: add lock depth to entriesSteven Rostedt4-10/+30
This patch adds the lock depth of the big kernel lock to the generic entry header. This way we can see the depth of the lock and help in removing the BKL. Example: # _------=> CPU# # / _-----=> irqs-off # | / _----=> need-resched # || / _---=> hardirq/softirq # ||| / _--=> preempt-depth # |||| /_--=> lock-depth # |||||/ delay # cmd pid |||||| time | caller # \ / |||||| \ | / <idle>-0 2.N..3 5902255250us+: lock_acquire: read rcu_read_lock <idle>-0 2.N..3 5902255253us+: lock_release: rcu_read_lock <idle>-0 2dN..3 5902255257us+: lock_acquire: xtime_lock <idle>-0 2dN..4 5902255259us : lock_acquire: clocksource_lock <idle>-0 2dN..4 5902255261us+: lock_release: clocksource_lock Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-09-11Merge branch 'writeback' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds1-0/+1
* 'writeback' of git://git.kernel.dk/linux-2.6-block: writeback: check for registered bdi in flusher add and inode dirty writeback: add name to backing_dev_info writeback: add some debug inode list counters to bdi stats writeback: get rid of pdflush completely writeback: switch to per-bdi threads for flushing data writeback: move dirty inodes from super_block to backing_dev_info writeback: get rid of generic_sync_sb_inodes() export
2009-09-11tracing: move tgid out of generic entry and into userstackSteven Rostedt4-6/+4
The userstack trace required the recording of the tgid entry. Unfortunately, it was added to the generic entry where it wasted 4 bytes of every entry and was only used by one entry. This patch moves it out of the generic field and moves it into the only user (userstack_entry). Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-09-11tracing: add latency format to function_graph tracerSteven Rostedt1-6/+68
While debugging something with the function_graph tracer, I found the need to see the preempt count of the traces. Unfortunately, since the function graph tracer has its own output formatting, it does not honor the latency-format option. This patch makes the function_graph tracer honor the latency-format option, but still keeps control of the output. But now we have the same details that the latency-format supplies. # tracer: function_graph # # _-----=> irqs-off # / _----=> need-resched # | / _---=> hardirq/softirq # || / _--=> preempt-depth # ||| / # |||| # CPU|||| DURATION FUNCTION CALLS # | |||| | | | | | | 3) d..1 1.333 us | idle_cpu(); 3) d.h1 | tick_check_idle() { 3) d.h1 0.550 us | tick_check_oneshot_broadcast(); 3) d.h1 | tick_nohz_stop_idle() { 3) d.h1 | ktime_get() { 3) d.h1 | ktime_get_ts() { Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-09-11block: add blk-iopoll, a NAPI like approach for block devicesJens Axboe1-1/+9
This borrows some code from NAPI and implements a polled completion mode for block devices. The idea is the same as NAPI - instead of doing the command completion when the irq occurs, schedule a dedicated softirq in the hopes that we will complete more IO when the iopoll handler is invoked. Devices have a budget of commands assigned, and will stay in polled mode as long as they continue to consume their budget from the iopoll softirq handler. If they do not, the device is set back to interrupt completion mode. This patch holds the core bits for blk-iopoll, device driver support sold separately. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-09-11writeback: add name to backing_dev_infoJens Axboe1-0/+1
This enables us to track who does what and print info. Its main use is catching dirty inodes on the default_backing_dev_info, so we can fix that up. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-09-11Merge branch 'next' into for-linusJames Morris7-13/+306
2009-09-10sched: Fix sched::sched_stat_wait tracepoint fieldIngo Molnar1-2/+1
This weird perf trace output: cc1-9943 [001] 2802.059479616: sched_stat_wait: task: as:9944 wait: 2801938766276 [ns] Is caused by setting one component field of the delta to zero a bit too early. Move it to later. ( Note, this does not affect the NEW_FAIR_SLEEPERS interactivity bug, it's just a reporting bug in essence. ) Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Nikos Chantziaras <realnc@arcor.de> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <4AA93D34.8040500@arcor.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-10sched: Disable NEW_FAIR_SLEEPERS for nowIngo Molnar1-1/+1
Nikos Chantziaras and Jens Axboe reported that turning off NEW_FAIR_SLEEPERS improves desktop interactivity visibly. Nikos described his experiences the following way: " With this setting, I can do "nice -n 19 make -j20" and still have a very smooth desktop and watch a movie at the same time. Various other annoyances (like the "logout/shutdown/restart" dialog of KDE not appearing at all until the background fade-out effect has finished) are also gone. So this seems to be the single most important setting that vastly improves desktop behavior, at least here. " Jens described it the following way, referring to a 10-seconds xmodmap scheduling delay he was trying to debug: " Then I tried switching NO_NEW_FAIR_SLEEPERS on, and then I get: Performance counter stats for 'xmodmap .xmodmap-carl': 9.009137 task-clock-msecs # 0.447 CPUs 18 context-switches # 0.002 M/sec 1 CPU-migrations # 0.000 M/sec 315 page-faults # 0.035 M/sec 0.020167093 seconds time elapsed Woot! " So disable it for now. In perf trace output i can see weird delta timestamps: cc1-9943 [001] 2802.059479616: sched_stat_wait: task: as:9944 wait: 2801938766276 [ns] That nsec field is not supposed to be that large. More digging is needed - but lets turn it off while the real bug is found. Reported-by: Nikos Chantziaras <realnc@arcor.de> Tested-by: Nikos Chantziaras <realnc@arcor.de> Reported-by: Jens Axboe <jens.axboe@oracle.com> Tested-by: Jens Axboe <jens.axboe@oracle.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <4AA93D34.8040500@arcor.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-10tracing: move PRED macros to trace_events_filter.cLi Zefan2-41/+41
Move DEFINE_COMPARISON_PRED() and DEFINE_EQUALITY_PRED() to kernel/trace/trace_events_filter.c Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> LKML-Reference: <4AA8579B.4020706@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-09-10tracing: remove stats from struct tracerLi Zefan1-1/+0
Remove unused field @stats from struct tracer. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> LKML-Reference: <4AA8579B.4020706@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-09-10tracing: format clean upsLi Zefan1-11/+11
Fix white-space formatting. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> LKML-Reference: <4AA8579B.4020706@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-09-10tracing: remove dead codeLi Zefan1-22/+0
Removes unreachable code. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> LKML-Reference: <4AA8579B.4020706@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-09-10tracing: do not grab lock in wakeup latency function tracingSteven Rostedt1-14/+22
The wakeup tracer, when enabled, has its own function tracer. It only traces the functions on the CPU where the task it is following is on. If a task is woken on one CPU but then migrates to another CPU before it wakes up, the latency tracer will then start tracing functions on the other CPU. To find which CPU the task is on, the wakeup function tracer performs a task_cpu(wakeup_task). But to make sure the task does not disappear it grabs the wakeup_lock, which is also taken when the task wakes up. By taking this lock, the function tracer does not need to worry about the task being freed as it checks its cpu. Jan Blunck found a problem with this approach on his 32 CPU box. When a task is being traced by the wakeup tracer, all functions take this lock. That means that on all 32 CPUs, each function call is taking this one lock to see if the task is on that CPU. This lock has just serialized all functions on all 32 CPUs. Needless to say, this caused major issues on that box. It would even lockup. This patch changes the wakeup latency to insert a probe on the migrate task tracepoint. When a task changes its CPU that it will run on, the probe will take note. Now the wakeup function tracer no longer needs to take the lock. It only compares the current CPU with a variable that holds the current CPU the task is on. We don't worry about races since it is OK to add or miss a function trace. Reported-by: Jan Blunck <jblunck@suse.de> Tested-by: Jan Blunck <jblunck@suse.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-09-10ring-buffer: consolidate interface of rb_buffer_peek()Robert Richter1-7/+4
rb_buffer_peek() operates with struct ring_buffer_per_cpu *cpu_buffer only. Thus, instead of passing variables buffer and cpu it is better to use cpu_buffer directly. This also reduces the risk of races since cpu_buffer is not calculated twice. Signed-off-by: Robert Richter <robert.richter@amd.com> LKML-Reference: <1249045084-3028-1-git-send-email-robert.richter@amd.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-09-10Merge branch 'master' into for-linusRafael J. Wysocki8-46/+43
2009-09-09sched: Keep kthreads at default priorityMike Galbraith2-6/+0
Removes kthread/workqueue priority boost, they increase worst-case desktop latencies. Signed-off-by: Mike Galbraith <efault@gmx.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1252486344.28645.18.camel@marge.simson.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-09sched: Re-tune the scheduler latency defaults to decrease worst-case latenciesMike Galbraith1-6/+6
Reduce the latency target from 20 msecs to 5 msecs. Why? Larger latencies increase spread, which is good for scaling, but bad for worst case latency. We still have the ilog(nr_cpus) rule to scale up on bigger server boxes. Signed-off-by: Mike Galbraith <efault@gmx.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1252486344.28645.18.camel@marge.simson.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-09sched: Turn off child_runs_firstMike Galbraith2-10/+10
Set child_runs_first default to off. It hurts 'optimal' make -j<NR_CPUS> workloads as make jobs get preempted by child tasks, reducing parallelism. Note, this patch might make existing races in user applications more prominent than before - so breakages might be bisected to this commit. Child-runs-first is broken on SMP to begin with, and we already had it off briefly in v2.6.23 so most of the offenders ought to be fixed. Would be nice not to revert this commit but fix those apps finally ... Signed-off-by: Mike Galbraith <efault@gmx.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1252486344.28645.18.camel@marge.simson.net> [ made the sysctl independent of CONFIG_SCHED_DEBUG, in case people want to work around broken apps. ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-08sched: Ensure that a child can't gain time over it's parent after fork()Mike Galbraith1-3/+5
A fork/exec load is usually "pass the baton", so the child should never be placed behind the parent. With START_DEBIT we make room for the new task, but with child_runs_first, that room comes out of the _parent's_ hide. There's nothing to say that the parent wasn't ahead of min_vruntime at fork() time, which means that the "baton carrier", who is essentially the parent in drag, can gain time and increase scheduling latencies for waiters. With NEW_FAIR_SLEEPERS + START_DEBIT + child_runs_first enabled, we essentially pass the sleeper fairness off to the child, which is fine, but if we don't base placement on the parent's updated vruntime, we can end up compounding latency woes if the child itself then does fork/exec. The debit incurred at fork doesn't hurt the parent who is then going to sleep and maybe exit, but the child who acquires the error harms all comers. This improves latencies of make -j<n> kernel build workloads. Reported-by: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Mike Galbraith <efault@gmx.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-07sched: Deal with low-load in wake_affine()Peter Zijlstra1-1/+11
wake_affine() would always fail under low-load situations where both prev and this were idle, because adding a single task will always be a significant imbalance, even if there's nothing around that could balance it. Deal with this by allowing imbalance when there's nothing you can do about it. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-07sched: Remove short cut from select_task_rq_fair()Peter Zijlstra1-2/+0
select_task_rq_fair() incorrectly skips the wake_affine() logic, remove this. When prev_cpu == this_cpu, the code jumps straight to the wake_idle() logic, this doesn't give the wake_affine() logic the chance to pin the task to this cpu. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-07Security/SELinux: includecheck fix kernel/sysctl.cJaswinder Singh Rajput1-1/+0
fix the following 'make includecheck' warning: kernel/sysctl.c: linux/security.h is included more than once. Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-09-06Merge branch 'tracing/core' of ↵Ingo Molnar1-5/+6
git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing into tracing/core
2009-09-06Merge commit 'v2.6.31-rc9' into tracing/coreIngo Molnar14-184/+342
Merge reason: move from -rc5 to -rc9. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-06Merge branch 'perfcounters-fixes-for-linus' of ↵Linus Torvalds1-1/+2
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'perfcounters-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: perf_counter/powerpc: Fix cache event codes for POWER7 perf_counter: Fix /0 bug in swcounters perf_counters: Increase paranoia level
2009-09-05ring-buffer: only enable ring_buffer_swap_cpu when neededSteven Rostedt2-0/+12
Since the ability to swap the cpu buffers adds a small overhead to the recording of a trace, we only want to add it when needed. Only the irqsoff and preemptoff tracers use this feature, and both are not recommended for production kernels. This patch disables its use when neither irqsoff nor preemptoff is configured. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-09-05ring-buffer: check for swapped buffers in start of committingSteven Rostedt1-3/+17
Because the irqsoff tracer can swap an internal CPU buffer, it is possible that a swap happens between the start of the write and before the committing bit is set (the committing bit will disable swapping). This patch adds a check for this and will fail the write if it detects it. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-09-05tracing: report error in trace if we fail to swap latency bufferSteven Rostedt1-1/+12
The irqsoff tracer will fail to swap the cpu buffer with the max buffer if it preempts a commit. Instead of ignoring this, this patch makes the tracer report it if the last max latency failed due to preempting a current commit. The output of the latency tracer will look like this: # tracer: irqsoff # # irqsoff latency trace v1.1.5 on 2.6.31-rc5 # -------------------------------------------------------------------- # latency: 112 us, #1/1, CPU#1 | (M:preempt VP:0, KP:0, SP:0 HP:0 #P:4) # ----------------- # | task: -4281 (uid:0 nice:0 policy:0 rt_prio:0) # ----------------- # => started at: save_args # => ended at: __do_softirq # # # _------=> CPU# # / _-----=> irqs-off # | / _----=> need-resched # || / _---=> hardirq/softirq # ||| / _--=> preempt-depth # |||| / # ||||| delay # cmd pid ||||| time | caller # \ / ||||| \ | / bash-4281 1d.s6 265us : update_max_tr_single: Failed to swap buffers due to commit in progress Note the latency time and the functions that disabled the irqs or preemption will still be listed. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-09-05tracing: add trace_array_printk for internal tracers to useSteven Rostedt2-2/+27
This patch adds a trace_array_printk to allow a tracer to use the trace_printk on its own trace array. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-09-05tracing: pass around ring buffer instead of tracerSteven Rostedt10-99/+143
The latency tracers (irqsoff and wakeup) can swap trace buffers on the fly. If an event is happening and has reserved data on one of the buffers, and the latency tracer swaps the global buffer with the max buffer, the result is that the event may commit the data to the wrong buffer. This patch changes the API to the trace recording to be recieve the buffer that was used to reserve a commit. Then this buffer can be passed in to the commit. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
generated by cgit v1.2.3 (git 2.39.0) at 2025-09-26 23:28:02 +0300