Re: [LAD] a *simple* ring buffer, comments pls?

On 8 July 2011 12:24, James Morris <jwm.art.net@email-addr-hidden> wrote:

> So I'd thought I'd compare the execution time of 7000 items passing
> through the two 32-item ring buffers, with the execution time 7000
> items passing though 32-item jack-ringbuffers. details to come,
> probably to throw all this out the window.
>

    MSG_BUF_SIZE = 32,
    MSG_COUNT = 700000

JACK RING BUF:
[sirrom@email-addr-hidden msg_test]$ time ./msg_test
          msg_test.c: 164 main(): read
back loop count:700032

real 0m0.136s
user 0m0.260s
sys 0m0.003s
[sirrom@email-addr-hidden msg_test]$ time ./msg_test
          msg_test.c: 164 main(): read
back loop count:700032

real 0m0.136s
user 0m0.263s
sys 0m0.000s
[sirrom@email-addr-hidden msg_test]$ time ./msg_test
          msg_test.c: 164 main(): read
back loop count:700032

real 0m0.142s
user 0m0.273s
sys 0m0.003s

MY RING BUF WITH ATOMIC POINTERS

[sirrom@email-addr-hidden msg_test]$ time ./msg_test
          msg_test.c: 286 main(): read
back loop count:702657

real 0m0.169s
user 0m0.330s
sys 0m0.000s
[sirrom@email-addr-hidden msg_test]$ time ./msg_test
          msg_test.c: 286 main(): read
back loop count:738329

real 0m0.173s
user 0m0.337s
sys 0m0.000s
[sirrom@email-addr-hidden msg_test]$ time ./msg_test
          msg_test.c: 286 main(): read
back loop count:753976

real 0m0.171s
user 0m0.333s
sys 0m0.000s

A very simple data integrity check was used, (note: pointers to data
were stored in the rbufs rather than data), the main thread set the
items data to point to the item itself. the integrity check was that
it should come back intact, still pointing to itself. success in both
instances.

JACK's ringbuf, as most will have undoubtedly known all along, is
faster, and the test code required 50000 iterations less than when
using my ring buf. maybe somewhere, the atomics are required?
james.
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Received on Fri Jul 8 16:15:02 2011