kernel_optimize_test/tools/perf
Davidlohr Bueso 121dd9ea01 perf bench: Add epoll parallel epoll_wait benchmark
This program benchmarks concurrent epoll_wait(2) for file descriptors
that are monitored with with EPOLLIN along various semantics, by a
single epoll instance. Such conditions can be found when using
single/combined or multiple queuing when load balancing.

Each thread has a number of private, nonblocking file descriptors,
referred to as fdmap. A writer thread will constantly be writing to the
fdmaps of all threads, minimizing each threads's chances of epoll_wait
not finding any ready read events and blocking as this is not what we
want to stress. Full details in the start of the C file.

Committer testing:

  # perf bench
  Usage:
	perf bench [<common options>] <collection> <benchmark> [<options>]

        # List of all available benchmark collections:

         sched: Scheduler and IPC benchmarks
           mem: Memory access benchmarks
          numa: NUMA scheduling and MM benchmarks
         futex: Futex stressing benchmarks
         epoll: Epoll stressing benchmarks
           all: All benchmarks

  # perf bench epoll

        # List of available benchmarks for collection 'epoll':

          wait: Benchmark epoll concurrent epoll_waits
           all: Run all futex benchmarks

  # perf bench epoll wait
  # Running 'epoll/wait' benchmark:
  Run summary [PID 19295]: 3 threads monitoring on 64 file-descriptors for 8 secs.

  [thread  0] fdmap: 0xdaa650 ... 0xdaa74c [ 328241 ops/sec ]
  [thread  1] fdmap: 0xdaa900 ... 0xdaa9fc [ 351695 ops/sec ]
  [thread  2] fdmap: 0xdaabb0 ... 0xdaacac [ 381423 ops/sec ]

  Averaged 353786 operations/sec (+- 4.35%), total secs = 8
  #

Committer notes:

Fix the build on debian:experimental-x-mips, debian:experimental-x-mipsel
and others:

    CC       /tmp/build/perf/bench/epoll-wait.o
  bench/epoll-wait.c: In function 'writerfn':
  bench/epoll-wait.c:399:12: error: format '%ld' expects argument of type 'long int', but argument 2 has type 'size_t' {aka 'unsigned int'} [-Werror=format=]
    printinfo("exiting writer-thread (total full-loops: %ld)\n", iter);
              ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  ~~~~
  bench/epoll-wait.c:86:31: note: in definition of macro 'printinfo'
    do { if (__verbose) { printf(fmt, ## arg); fflush(stdout); } } while (0)
                                 ^~~
  cc1: all warnings being treated as errors

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: Jason Baron <jbaron@akamai.com> <jbaron@akamai.com>
Link: http://lkml.kernel.org/r/20181106152226.20883-2-dave@stgolabs.net
Link: http://lkml.kernel.org/r/20181106182349.thdkpvshkna5vd7o@linux-r8p5>
[ Applied above fixup as per Davidlohr's request ]
[ Use inttypes.h to print rlim_t fields, fixing the build on Alpine Linux / musl libc ]
[ Check if eventfd() is available, i.e. if HAVE_EVENTFD is defined ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2018-11-21 22:38:47 -03:00
..
arch Merge branch 'linus' into perf/urgent, to pick up fixes 2018-10-29 07:20:52 +01:00
bench perf bench: Add epoll parallel epoll_wait benchmark 2018-11-21 22:38:47 -03:00
Documentation perf bench: Add epoll parallel epoll_wait benchmark 2018-11-21 22:38:47 -03:00
examples/bpf Revert "perf augmented_syscalls: Drop 'write', 'poll' for testing without self pid filter" 2018-11-21 12:00:31 -03:00
include/bpf perf bpf: Reduce the hardcoded .max_entries for pid_maps 2018-11-21 12:00:32 -03:00
jvmti perf tools: Fix undefined symbol scnprintf in libperf-jvmti.so 2018-11-05 16:28:00 -03:00
pmu-events
python
scripts perf scripts python: exported-sql-viewer.py: Fix table find when table re-ordered 2018-11-05 14:53:00 -03:00
tests perf tools: Fix crash on synthesizing the unit 2018-11-12 08:37:49 -08:00
trace perf tools beauty ioctl: Support new ISO7816 commands 2018-11-19 12:38:50 -08:00
ui
util perf evlist: Rename perf_evlist__set_filter* to perf_evlist__set_tp_filter* 2018-11-21 12:00:31 -03:00
.gitignore
Build
builtin-annotate.c
builtin-bench.c perf bench: Add epoll parallel epoll_wait benchmark 2018-11-21 22:38:47 -03:00
builtin-buildid-cache.c
builtin-buildid-list.c
builtin-c2c.c
builtin-config.c
builtin-data.c
builtin-diff.c
builtin-evlist.c
builtin-ftrace.c
builtin-help.c
builtin-inject.c
builtin-kallsyms.c
builtin-kmem.c
builtin-kvm.c
builtin-list.c
builtin-lock.c
builtin-mem.c
builtin-probe.c
builtin-record.c perf record: Support weak groups 2018-11-05 14:37:10 -03:00
builtin-report.c
builtin-sched.c
builtin-script.c perf script: Share code and output format for uregs and iregs output 2018-11-21 12:00:32 -03:00
builtin-stat.c perf evlist: Move perf_evsel__reset_weak_group into evlist 2018-11-05 14:37:09 -03:00
builtin-timechart.c
builtin-top.c perf top: Display the LBR stats in callchain entry 2018-11-05 14:37:11 -03:00
builtin-trace.c perf trace: Fill in BPF "filtered_pids" map when present 2018-11-21 12:00:31 -03:00
builtin-version.c
builtin.h
check-headers.sh tools include uapi: Grab a copy of linux/fs.h 2018-10-30 11:46:22 -03:00
command-list.txt
CREDITS
design.txt
Makefile
Makefile.config tools build feature: Check if eventfd() is available 2018-11-21 22:25:44 -03:00
Makefile.perf perf beauty: Use SRCARCH, ARCH=x86_64 must map to "x86" to find the headers 2018-11-05 15:46:51 -03:00
MANIFEST
perf-archive.sh
perf-completion.sh
perf-read-vdso.c
perf-sys.h
perf-with-kcore.sh
perf.c
perf.h