Re: [PATCH] readahead:add blk_run_backing_dev

KOSAKI Motohiro
2009-05-27T03:26:17Z

> >> >The numbers look too small for a 7 disk RAID:
> >> >
> >> > > #dd if=testdir/testfile of=/dev/null bs=16384
> >> > >
> >> > > -2.6.30-rc6
> >> > > 1048576+0 records in
> >> > > 1048576+0 records out
> >> > > 17179869184 bytes (17 GB) copied, 224.182 seconds, 76.6 MB/s
> >> > >
> >> > > -2.6.30-rc6-patched
> >> > > 1048576+0 records in
> >> > > 1048576+0 records out
> >> > > 17179869184 bytes (17 GB) copied, 206.465 seconds, 83.2 MB/s
> >> >
> >> >I'd suggest you to configure the array properly before coming back to
> >> >measuring the impact of this patch.
> >>
> >>
> >> I created 16GB file to this disk array, and mounted to testdir, dd to
> >this directory.
> >
> >I mean, you should get >300MB/s throughput with 7 disks, and you
> >should seek ways to achieve that before testing out this patch :-)
>
> Throughput number of storage array is very from one product to another.
> On my hardware environment I think this number is valid and
> my patch is effective.

Hifumi-san, if you really want to merge, you should reproduce this
issue on typical hardware, I think.