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linux/kernel/trace
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Steven Rostedt (VMware) bbeba3e58f ring-buffer: Call trace_clock_local() directly for RETPOLINE kernels 
After doing some benchmarks and examining the code, I found that the ring
buffer clock calls were quite expensive, and noticed that it uses
retpolines. This is because the ring buffer clock is programmable, and can
be set. But in most cases it simply uses the fastest ns unit clock which is
the trace_clock_local(). For RETPOLINE builds, checking if the ring buffer
clock is set to trace_clock_local() and then calling it directly has brought
the time of an event on my i7 box from an average of 93 nanoseconds an event
down to 83 nanoseconds an event, and the minimum time from 81 nanoseconds to
68 nanoseconds!

Suggested-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-07-01 22:12:07 -04:00
..
blktrace.c blktrace: Avoid sparse warnings when assigning q->blk_trace 2020-06-17 09:07:11 -06:00
bpf_trace.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-06-25 18:27:40 -07:00
fgraph.c tracing: Define MCOUNT_INSN_SIZE when not defined without direct calls 2020-01-02 21:56:44 -05:00
ftrace.c x86/ftrace: Only have the builtin ftrace_regs_caller call direct hooks 2020-06-29 11:42:47 -04:00
ftrace_internal.h x86/ftrace: Have ftrace trampolines turn read-only at the end of system boot up 2020-05-12 18:24:34 -04:00
Kconfig Tracing updates for 5.8: 2020-06-09 10:06:18 -07:00
kprobe_event_gen_test.c tracing: Add kprobe event command generation test module 2020-01-30 09:46:28 -05:00
Makefile Rebase locking/kcsan to locking/urgent 2020-06-11 20:02:46 +02:00
power-traces.c
preemptirq_delay_test.c tracing: Wait for preempt irq delay thread to execute 2020-05-11 17:00:34 -04:00
ring_buffer.c ring-buffer: Call trace_clock_local() directly for RETPOLINE kernels 2020-07-01 22:12:07 -04:00
ring_buffer_benchmark.c tracing: Make struct ring_buffer less ambiguous 2020-01-13 13:19:38 -05:00
rpm-traces.c
synth_event_gen_test.c tracing: Have synthetic event test use raw_smp_processor_id() 2020-02-20 17:43:41 -05:00
trace.c ring-buffer: speed up buffer resets by avoiding synchronize_rcu for each CPU 2020-06-30 17:18:56 -04:00
trace.h tracing: Move pipe reference to trace array instead of current_tracer 2020-06-30 14:29:33 -04:00
trace_benchmark.c
trace_benchmark.h
trace_boot.c tracing/boottime: Fix kprobe multiple events 2020-06-23 21:51:50 -04:00
trace_branch.c tracing: Make struct ring_buffer less ambiguous 2020-01-13 13:19:38 -05:00
trace_clock.c
trace_dynevent.c tracing: Use seq_buf for building dynevent_cmd string 2020-02-01 13:10:15 -05:00
trace_dynevent.h tracing: Remove check_arg() callbacks from dynevent args 2020-02-01 13:09:23 -05:00
trace_entries.h tracing: Make ftrace packed events have align of 1 2020-06-16 21:21:02 -04:00
trace_event_perf.c
trace_events.c tracing: Add hist_debug trace event files for histogram debugging 2020-06-01 08:22:30 -04:00
trace_events_filter.c tracing: Avoid memory leak in process_system_preds() 2019-12-19 18:24:17 -05:00
trace_events_filter_test.h
trace_events_hist.c tracing: Move synthetic events to a separate file 2020-06-01 08:23:22 -04:00
trace_events_inject.c tracing: Initialize val to zero in parse_entry of inject code 2020-01-02 19:04:57 -05:00
trace_events_synth.c tracing: Move synthetic events to a separate file 2020-06-01 08:23:22 -04:00
trace_events_trigger.c tracing: Fix event trigger to accept redundant spaces 2020-06-23 21:51:40 -04:00
trace_export.c tracing: Make ftrace packed events have align of 1 2020-06-16 21:21:02 -04:00
trace_functions.c trace: Fix typo in allocate_ftrace_ops()'s comment 2020-06-16 21:21:02 -04:00
trace_functions_graph.c ring-buffer: Rename ring_buffer_read() to read_buffer_iter_advance() 2020-03-19 19:11:19 -04:00
trace_hwlat.c tracing: Have hwlat ts be first instance and record count of instances 2020-03-03 17:33:43 -05:00
trace_irqsoff.c tracing: Rename trace_buffer to array_buffer 2020-01-13 13:19:38 -05:00
trace_kdb.c tracing: Rename trace_buffer to array_buffer 2020-01-13 13:19:38 -05:00
trace_kprobe.c maccess: rename probe_user_{read,write} to copy_{from,to}_user_nofault 2020-06-17 10:57:41 -07:00
trace_kprobe_selftest.c
trace_kprobe_selftest.h
trace_mmiotrace.c tracing: Make struct ring_buffer less ambiguous 2020-01-13 13:19:38 -05:00
trace_nop.c
trace_output.c mmap locking API: use coccinelle to convert mmap_sem rwsem call sites 2020-06-09 09:39:14 -07:00
trace_output.h
trace_preemptirq.c x86/entry: Rename trace_hardirqs_off_prepare() 2020-06-11 15:15:24 +02:00
trace_printk.c
trace_probe.c tracing/probe: Fix memleak in fetch_op_data operations 2020-06-16 21:21:02 -04:00
trace_probe.h tracing/probe: Replace zero-length array with flexible-array 2020-06-15 23:08:32 -05:00
trace_probe_tmpl.h
trace_sched_switch.c tracing: Fix sched switch start/stop refcount racy updates 2020-01-30 09:46:10 -05:00
trace_sched_wakeup.c tracing: Make struct ring_buffer less ambiguous 2020-01-13 13:19:38 -05:00
trace_selftest.c tracing: Rename trace_buffer to array_buffer 2020-01-13 13:19:38 -05:00
trace_selftest_dynamic.c
trace_seq.c tracing: Remove unused TRACE_SEQ_BUF_USED 2020-01-21 18:39:54 -05:00
trace_stack.c trace: fix an incorrect __user annotation on stack_trace_sysctl 2020-06-08 10:13:56 -04:00
trace_stat.c tracing: Fix tracing_stat return values in error handling paths 2020-01-24 18:06:48 -05:00
trace_stat.h
trace_synth.h tracing: Move synthetic events to a separate file 2020-06-01 08:23:22 -04:00
trace_syscalls.c Tracing updates: 2020-02-06 07:12:11 +00:00
trace_uprobe.c tracing/probe: Fix bpf_task_fd_query() for kprobes and uprobes 2020-06-09 11:10:12 -07:00
tracing_map.c tracing: Convert local functions in tracing_map.c to static 2020-04-22 22:07:26 -04:00
tracing_map.h