linux/tools
Wang Nan f06149c0db perf session: Don't warn about out of order event if write_backward is used
If write_backward attribute is set, records are written into kernel
ring buffer from end to beginning, but read from beginning to end.
To avoid 'XX out of order events recorded' warning message (timestamps
of records is in reverse order when using write_backward), suppress the
warning message if write_backward is selected by at lease one event.

Result:

Before this patch:
  # perf record -m 1 -e raw_syscalls:sys_exit/overwrite/ \
                     -e raw_syscalls:sys_enter \
                     dd if=/dev/zero of=/dev/null count=300
  300+0 records in
  300+0 records out
  153600 bytes (154 kB) copied, 0.000601617 s, 255 MB/s
  [ perf record: Woken up 5 times to write data ]
  Warning:
  40 out of order events recorded.
  [ perf record: Captured and wrote 0.096 MB perf.data (696 samples) ]

After this patch:
  # perf record -m 1 -e raw_syscalls:sys_exit/overwrite/ \
                     -e raw_syscalls:sys_enter \
                     dd if=/dev/zero of=/dev/null count=300
  300+0 records in
  300+0 records out
  153600 bytes (154 kB) copied, 0.000644873 s, 238 MB/s
  [ perf record: Woken up 5 times to write data ]
  [ perf record: Captured and wrote 0.096 MB perf.data (696 samples) ]

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Nilay Vaish <nilayvaish@gmail.com>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1468485287-33422-15-git-send-email-wangnan0@huawei.com
Signed-off-by: He Kuang <hekuang@huawei.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-07-15 17:27:51 -03:00
..
arch tools: Copy the bitsperlong.h files from the kernel 2016-07-12 15:20:39 -03:00
build perf build: Add sdt feature detection 2016-07-13 23:09:09 -03:00
cgroup
firewire
gpio tools/gpio: Add missing initialization of device_name 2016-03-31 11:51:30 +02:00
hv tools: hv: lsvmbus: add pci pass-through UUID 2016-05-01 09:23:14 -07:00
iio iio: tools: generic_buffer: auto-enable channels 2016-04-19 19:58:13 +01:00
include tools: Simplify BITS_PER_LONG define 2016-07-15 17:26:41 -03:00
kvm/kvm_stat tools: kvm_stat: Add comments 2016-05-25 16:12:06 +02:00
laptop/freefall
lguest tools/lguest: Force disable tboot and APM 2016-04-22 10:29:03 +02:00
lib tools lib fd array: Allow associating a pointer cookie with each entry 2016-07-15 17:27:46 -03:00
net tools: bpf_jit_disasm: check for klogctl failure 2016-05-08 23:32:59 -04:00
nfsd
objtool objtool: Avoid checking code drift on busybox's diff 2016-07-13 23:08:54 -03:00
perf perf session: Don't warn about out of order event if write_backward is used 2016-07-15 17:27:51 -03:00
power Merge branch 'for-4.7/acpi6.1' into libnvdimm-for-next 2016-05-18 10:07:19 -07:00
scripts tools: Move utilities.mak from perf to tools/scripts/ 2016-03-18 13:57:20 -03:00
spi spi: spidev_test: Fix typo in error message 2015-12-08 17:58:56 +00:00
testing selftests/vm/compaction_test: fix write to restore nr_hugepages 2016-06-24 17:23:52 -07:00
thermal/tmon tools/thermal: tmon: use pkg-config also for CFLAGS 2015-10-10 11:32:31 +08:00
time
usb usbip: adding names db to port operation 2016-05-03 14:32:07 -07:00
virtio tools/virtio: add noring tool 2016-06-06 13:00:11 +03:00
vm tools/vm/slabinfo: fix spelling mistake: "Ocurrences" -> "Occurrences" 2016-06-24 17:23:52 -07:00
Makefile - move kvm_stat tool from QEMU repo into tools/kvm/kvm_stat 2016-05-27 13:41:54 -07:00