Messages in this thread | | | Date | Thu, 27 Apr 2006 13:45:06 +0200 | From | Jens Axboe <> | Subject | Re: Lockless page cache test results |
| |
On Thu, Apr 27 2006, KAMEZAWA Hiroyuki wrote: > On Thu, 27 Apr 2006 13:16:25 +0200 > Jens Axboe <axboe@suse.de> wrote: > > > Added, 1 vs 2/3/4 clients isn't very interesting, so to keep it short > > here are numbers for 2 clients to /dev/null and localhost. > > > Thank you! looks splice has significant advantage :) > > > Sending to /dev/null > > > > ml370:/data # ./splice-bench -n2 -l10 -a -s -z file > > Waiting for clients > > Client1 (splice): 19030 MiB/sec (10240MiB in 551 msecs) > > Client0 (splice): 18961 MiB/sec (10240MiB in 553 msecs) > This maybe shows cost of gathering page-cache.
Precisely, it's basically the cost of looking up the pages and adding them to the pipe.
> > Client1 (mmap): 158875 MiB/sec (10240MiB in 66 msecs) > > Client0 (mmap): 158875 MiB/sec (10240MiB in 66 msecs) > This shows read/write system-call and user program cost. right ?
It shows the cost of write()'ing the mmap'ed file area to /dev/null.
> > Client1 (rw): 1691 MiB/sec (10240MiB in 6200 msecs) > > Client0 (rw): 1690 MiB/sec (10240MiB in 6201 msecs) > > > This shows 10240MiB copy_to_user() cost. > BTW, How big are cpu-cache-size and read/write buffer size in this test ?
This was done on a xeon with 2mb l2. The buffers size used was 64k in all cases.
> > Sending/receiving over lo > > > read from a file and write to lo ?
I'd rather say input is a file and output is a socket going to lo, that is a little more precisely given the differing methods the clients use. But I suspect this is what you meant.
-- Jens Axboe
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |