A bit dirty patch to collect and print latency histogram for disk
access. Example outputs:

kirr@deco:~/src/tools/fs/ioping$ ./ioping -i 100ms -D .
4 KiB <<< . (ext4 /dev/sda3): request=1 time=128.7 us (warmup)
4 KiB <<< . (ext4 /dev/sda3): request=2 time=262.9 us
4 KiB <<< . (ext4 /dev/sda3): request=3 time=282.2 us
...
4 KiB <<< . (ext4 /dev/sda3): request=170 time=259.5 us
^C
--- . (ext4 /dev/sda3) ioping statistics ---
169 requests completed in 45.8 ms, 676 KiB read, 3.69 k iops, 14.4 MiB/s
generated 170 requests in 17.0 s, 680 KiB, 10 iops, 40.0 KiB/s
min/avg/max/mdev = 142.9 us / 270.9 us / 378.1 us / 28.8 us
< 142.9 us      0       |
< 165.7 us      0       |
< 188.5 us      0       |
< 211.2 us      0       |
< 234.0 us      0       |
< 256.8 us      21      | ******
< 279.6 us      29      | ********
< 302.3 us      8       | **
< 325.1 us      5       | *
< 347.9 us      4       | *
< 370.7 us      1       |
<       +∞      1       |

kirr@deco:~/src/tools/fs/ioping$ ./ioping -R -S 1024M -k .

--- . (ext4 /dev/sda3) ioping statistics ---
17.1 k requests completed in 2.90 s, 66.7 MiB read, 5.89 k iops, 23.0 MiB/s
generated 17.1 k requests in 3.00 s, 66.8 MiB, 5.70 k iops, 22.2 MiB/s
min/avg/max/mdev = 119.4 us / 169.8 us / 3.83 ms / 260.2 us
< 298.2 us      16623   | ************************************************
< 651.4 us      110     |
< 1.00 ms       64      |
< 1.36 ms       35      |
< 1.71 ms       37      |
< 2.06 ms       33      |
< 2.42 ms       20      |
< 2.77 ms       17      |
< 3.12 ms       19      |
< 3.48 ms       25      |
< 3.83 ms       4       |
<       +∞      0       |

Makefile and man page nitpicks

In case we'd want to use some extra fancy tag.
Signed-off-by: Kir Kolyshkin <kir@openvz.org>

Otherwise, after the previous commit, we can't build it :)
Signed-off-by: Kir Kolyshkin <kir@openvz.org>

It's a common situation when git tag was updated, but a version in
the source code was not (or vice versa), and it's easy to catch it.

This is exactly what the code does.

Note we can still build the binary, but can no longer build rpm or
pack a source or binary tarball.

Alternatively, we can just send -DVERSION from the command line, but
it won't work in case .git is not present, so we just stop the build
(and let the human sort it out).
Signed-off-by: Kir Kolyshkin <kir@openvz.org>

Signed-off-by: Kir Kolyshkin <kir@openvz.org>

This is what CPPFLAGS is for.
Signed-off-by: Kir Kolyshkin <kir@openvz.org>

Signed-off-by: Kir Kolyshkin <kir@openvz.org>

Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com>

Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com>

example: -s 3/4m -- 768k, -i 1/10s -- 10 iops
Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com>

Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com>

Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com>

Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com>

Handle interval time as interval between requests starts.
Speed limit just set interval according to request size.
Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com>

Normal results exclude cache hits and intervals between requests.
This prints results for all requests and total running time.
Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com>

some crappy OSes don't have one.
Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com>

Couple new keys: -y for O_DSYNC and -Y for D_SYNC.
Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com>

This is just a hint, so print warning it fails.
Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com>

This call wakeups device, as a result first ping is much faster.

Now non-cached write will simply fail if target doesn't support
fdatasync (for example /dev/null).

Also tweak errors and warnings a little.
Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com>
Reported-by: Yuri Volchkov <yuri.volchkov@gmail.com>
Link: https://github.com/koct9i/ioping/pull/30

various build improvements

The -s flag to install breaks things when you cross-compile because
it only understands the native `strip`.  Just drop the flag and let
distros manage things themselves.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

This way people can replace the -O/-g settings w/out also messing up
the -std/-W settings.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

These contain user flags like -I/-D options.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

The makedev prototype is in sys/sysmacros.h, so include it.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com>

Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com>

Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com>

Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com>

Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com>

Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com>

Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com>

Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com>

Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com>

Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com>

Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com>

Updated Readme with Examples