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fde59ab161
Due to retpolines, indirect calls are much more expensive than direct
calls. The filters have a select set of functions it uses for the
predicates. Instead of using function pointers to call them, create a
filter_pred_fn_call() function that uses a switch statement to call the
predicate functions directly. This gives almost a 10% speedup to the
filter logic.
Using the histogram benchmark:
Before:
# event histogram
#
# trigger info: hist:keys=delta:vals=hitcount:sort=delta:size=2048 if delta > 0 [active]
#
{ delta: 113 } hitcount: 272
{ delta: 114 } hitcount: 840
{ delta: 118 } hitcount: 344
{ delta: 119 } hitcount: 25428
{ delta: 120 } hitcount: 350590
{ delta: 121 } hitcount: 1892484
{ delta: 122 } hitcount: 6205004
{ delta: 123 } hitcount: 11583521
{ delta: 124 } hitcount: 37590979
{ delta: 125 } hitcount: 108308504
{ delta: 126 } hitcount: 131672461
{ delta: 127 } hitcount: 88700598
{ delta: 128 } hitcount: 65939870
{ delta: 129 } hitcount: 45055004
{ delta: 130 } hitcount: 33174464
{ delta: 131 } hitcount: 31813493
{ delta: 132 } hitcount: 29011676
{ delta: 133 } hitcount: 22798782
{ delta: 134 } hitcount: 22072486
{ delta: 135 } hitcount: 17034113
{ delta: 136 } hitcount: 8982490
{ delta: 137 } hitcount: 2865908
{ delta: 138 } hitcount: 980382
{ delta: 139 } hitcount: 1651944
{ delta: 140 } hitcount: 4112073
{ delta: 141 } hitcount: 3963269
{ delta: 142 } hitcount: 1712508
{ delta: 143 } hitcount: 575941
After:
# event histogram
#
# trigger info: hist:keys=delta:vals=hitcount:sort=delta:size=2048 if delta > 0 [active]
#
{ delta: 103 } hitcount: 60
{ delta: 104 } hitcount: 16966
{ delta: 105 } hitcount: 396625
{ delta: 106 } hitcount: 3223400
{ delta: 107 } hitcount: 12053754
{ delta: 108 } hitcount: 20241711
{ delta: 109 } hitcount: 14850200
{ delta: 110 } hitcount: 4946599
{ delta: 111 } hitcount: 3479315
{ delta: 112 } hitcount: 18698299
{ delta: 113 } hitcount: 62388733
{ delta: 114 } hitcount: 95803834
{ delta: 115 } hitcount: 58278130
{ delta: 116 } hitcount: 15364800
{ delta: 117 } hitcount: 5586866
{ delta: 118 } hitcount: 2346880
{ delta: 119 } hitcount: 1131091
{ delta: 120 } hitcount: 620896
{ delta: 121 } hitcount: 236652
{ delta: 122 } hitcount: 105957
{ delta: 123 } hitcount: 119107
{ delta: 124 } hitcount: 54494
{ delta: 125 } hitcount: 63856
{ delta: 126 } hitcount: 64454
{ delta: 127 } hitcount: 34818
{ delta: 128 } hitcount: 41446
{ delta: 129 } hitcount: 51242
{ delta: 130 } hitcount: 28361
{ delta: 131 } hitcount: 23926
The peak before was 126ns per event, after the peak is 114ns, and the
fastest time went from 113ns to 103ns.
Link: https://lkml.kernel.org/r/20220906225529.781407172@goodmis.org
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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|---|---|---|
| .. | ||
| rv | ||
| blktrace.c | ||
| bpf_trace.c | ||
| bpf_trace.h | ||
| error_report-traces.c | ||
| fgraph.c | ||
| fprobe.c | ||
| ftrace.c | ||
| ftrace_internal.h | ||
| Kconfig | ||
| kprobe_event_gen_test.c | ||
| Makefile | ||
| pid_list.c | ||
| pid_list.h | ||
| power-traces.c | ||
| preemptirq_delay_test.c | ||
| rethook.c | ||
| ring_buffer.c | ||
| ring_buffer_benchmark.c | ||
| rpm-traces.c | ||
| synth_event_gen_test.c | ||
| trace.c | ||
| trace.h | ||
| trace_benchmark.c | ||
| trace_benchmark.h | ||
| trace_boot.c | ||
| trace_branch.c | ||
| trace_clock.c | ||
| trace_dynevent.c | ||
| trace_dynevent.h | ||
| trace_entries.h | ||
| trace_eprobe.c | ||
| trace_event_perf.c | ||
| trace_events.c | ||
| trace_events_filter.c | ||
| trace_events_filter_test.h | ||
| trace_events_hist.c | ||
| trace_events_inject.c | ||
| trace_events_synth.c | ||
| trace_events_trigger.c | ||
| trace_events_user.c | ||
| trace_export.c | ||
| trace_functions.c | ||
| trace_functions_graph.c | ||
| trace_hwlat.c | ||
| trace_irqsoff.c | ||
| trace_kdb.c | ||
| trace_kprobe.c | ||
| trace_kprobe_selftest.c | ||
| trace_kprobe_selftest.h | ||
| trace_mmiotrace.c | ||
| trace_nop.c | ||
| trace_osnoise.c | ||
| trace_output.c | ||
| trace_output.h | ||
| trace_preemptirq.c | ||
| trace_printk.c | ||
| trace_probe.c | ||
| trace_probe.h | ||
| trace_probe_tmpl.h | ||
| trace_recursion_record.c | ||
| trace_sched_switch.c | ||
| trace_sched_wakeup.c | ||
| trace_selftest.c | ||
| trace_selftest_dynamic.c | ||
| trace_seq.c | ||
| trace_stack.c | ||
| trace_stat.c | ||
| trace_stat.h | ||
| trace_synth.h | ||
| trace_syscalls.c | ||
| trace_uprobe.c | ||
| tracing_map.c | ||
| tracing_map.h | ||