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* tracing: Fix lockdep warning in global_clock()Li Zefan2010-03-291-2/+2
| | | | | | | | | | | | | | | | | | | | # echo 1 > events/enable # echo global > trace_clock ------------[ cut here ]------------ WARNING: at kernel/lockdep.c:3162 check_flags+0xb2/0x190() ... ---[ end trace 3f86734a89416623 ]--- possible reason: unannotated irqs-on. ... There's no reason to use the raw_local_irq_save() in trace_clock_global. The local_irq_save() version is fine, and does not cause the bug in lockdep. Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> LKML-Reference: <4BA97FA1.7030606@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Include irqflags headers from trace clockFrederic Weisbecker2010-02-281-0/+1
| | | | | | | | | | | | | | | | | | | | trace_clock.c includes spinlock.h, which ends up including asm/system.h, which in turn includes linux/irqflags.h in x86. So the definition of raw_local_irq_save is luckily covered there, but this is not the case in parisc: tip/kernel/trace/trace_clock.c:86: error: implicit declaration of function 'raw_local_irq_save' tip/kernel/trace/trace_clock.c:112: error: implicit declaration of function 'raw_local_irq_restore' We need to include linux/irqflags.h directly from trace_clock.c to avoid such build error. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Robert Richter <robert.richter@amd.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* locking: Convert __raw_spin* functions to arch_spin*Thomas Gleixner2009-12-141-2/+2
| | | | | | | | | | Name space cleanup. No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: linux-arch@vger.kernel.org
* locking: Rename __RAW_SPIN_LOCK_UNLOCKED to __ARCH_SPIN_LOCK_UNLOCKEDThomas Gleixner2009-12-141-1/+1
| | | | | | | | | | Further name space cleanup. No functional change Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: linux-arch@vger.kernel.org
* locking: Convert raw_spinlock to arch_spinlockThomas Gleixner2009-12-141-2/+2
| | | | | | | | | | | | | | | | | | | The raw_spin* namespace was taken by lockdep for the architecture specific implementations. raw_spin_* would be the ideal name space for the spinlocks which are not converted to sleeping locks in preempt-rt. Linus suggested to convert the raw_ to arch_ locks and cleanup the name space instead of using an artifical name like core_spin, atomic_spin or whatever No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: linux-arch@vger.kernel.org
* tracing: do not disable interrupts for trace_clock_localSteven Rostedt2009-11-111-3/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Disabling interrupts in trace_clock_local takes quite a performance hit to the recording of traces. Using perf top we see: ------------------------------------------------------------------------------ PerfTop: 244 irqs/sec kernel:100.0% [1000Hz cpu-clock-msecs], (all, 4 CPUs) ------------------------------------------------------------------------------ samples pcnt kernel function _______ _____ _______________ 2842.00 - 40.4% : trace_clock_local 1043.00 - 14.8% : rb_reserve_next_event 784.00 - 11.1% : ring_buffer_lock_reserve 600.00 - 8.5% : __rb_reserve_next 579.00 - 8.2% : rb_end_commit 440.00 - 6.3% : ring_buffer_unlock_commit 290.00 - 4.1% : ring_buffer_producer_thread [ring_buffer_benchmark] 155.00 - 2.2% : debug_smp_processor_id 117.00 - 1.7% : trace_recursive_unlock 103.00 - 1.5% : ring_buffer_event_data 28.00 - 0.4% : do_gettimeofday 22.00 - 0.3% : _spin_unlock_irq 14.00 - 0.2% : native_read_tsc 11.00 - 0.2% : getnstimeofday Where trace_clock_local is 40% of the tracing, and the time for recording a trace according to ring_buffer_benchmark is 210ns. After converting the interrupts to preemption disabling we have from perf top: ------------------------------------------------------------------------------ PerfTop: 1084 irqs/sec kernel:99.9% [1000Hz cpu-clock-msecs], (all, 4 CPUs) ------------------------------------------------------------------------------ samples pcnt kernel function _______ _____ _______________ 1277.00 - 16.8% : native_read_tsc 1148.00 - 15.1% : rb_reserve_next_event 896.00 - 11.8% : ring_buffer_lock_reserve 688.00 - 9.1% : __rb_reserve_next 664.00 - 8.8% : rb_end_commit 563.00 - 7.4% : ring_buffer_unlock_commit 508.00 - 6.7% : _spin_unlock_irq 365.00 - 4.8% : debug_smp_processor_id 321.00 - 4.2% : trace_clock_local 303.00 - 4.0% : ring_buffer_producer_thread [ring_buffer_benchmark] 273.00 - 3.6% : native_sched_clock 122.00 - 1.6% : trace_recursive_unlock 113.00 - 1.5% : sched_clock 101.00 - 1.3% : ring_buffer_event_data 53.00 - 0.7% : tick_nohz_stop_sched_tick Where trace_clock_local drops from 40% to only taking 4% of the total time. The trace time also goes from 210ns down to 179ns (31ns). I talked with Peter Zijlstra about the impact that sched_clock may have without having interrupts disabled, and he told me that if a timer interrupt comes in, sched_clock may report a wrong time. Balancing a seldom incorrect timestamp with a 15% performance boost, I'll take the performance boost. Acked-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: optimize global_trace_clock cachelinesSteven Rostedt2009-09-151-10/+14
| | | | | | | | | The prev_trace_clock_time is only read or written to when the trace_clock_lock is taken. For better perfomance, they should share the same cache line. Reported-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: fix four sparse warningsDmitri Vorobiev2009-03-221-0/+1
| | | | | | | | | | | | | | | | | | | | | | Impact: cleanup. This patch fixes the following sparse warnings: kernel/trace/trace.c:385:9: warning: symbol 'trace_seq_to_buffer' was not declared. Should it be static? kernel/trace/trace_clock.c:29:13: warning: symbol 'trace_clock_local' was not declared. Should it be static? kernel/trace/trace_clock.c:54:13: warning: symbol 'trace_clock' was not declared. Should it be static? kernel/trace/trace_clock.c:74:13: warning: symbol 'trace_clock_global' was not declared. Should it be static? Signed-off-by: Dmitri Vorobiev <dmitri.vorobiev@movial.com> LKML-Reference: <1237741871-5827-4-git-send-email-dmitri.vorobiev@movial.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* trace_clock: fix preemption bugPeter Zijlstra2009-03-101-1/+8
| | | | | | | | | | | Using the function_graph tracer in recent kernels generates a spew of preemption BUGs. Fix this by not requiring trace_clock_local() users to disable preemption themselves. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* tracing: implement trace_clock_*() APIsIngo Molnar2009-02-261-0/+101
Impact: implement new tracing timestamp APIs Add three trace clock variants, with differing scalability/precision tradeoffs: - local: CPU-local trace clock - medium: scalable global clock with some jitter - global: globally monotonic, serialized clock Make the ring-buffer use the local trace clock internally. Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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