Re: [RFC v1][PATCH]page_fault retry with NOPAGE_RETRY

["Török Edwin" <edwintorok@gmail.com>]

On 2008-12-05 00:27, Ying Han wrote:
> I am trying your test program(scalability) in house, but somehow i got
> different result as you saw. i created 8 files each with 1G size on
> separate drives( to avoid the latency disturbing of disk seek). I got
> this number without applying the batch based on 2.6.26. May i ask how
> to reproduce the mmap issue you mentioned?
>   

Hi,

Try using more files, and of smaller size.  I was using /usr/bin, which
has 3632 files, and 571M total.
I am using XFS filesystem: /dev/mapper/vg--all-lv--usr on /usr type xfs
(rw,noatime,logbsize=262144,logbufs=8,logdev=/dev/sdg6,inode64)


> 8 CPU
> read_worker
> 1 threads Real time: 101.058262 s (since task start)
> 2 threads Real time: 50.670456 s (since task start)
> 4 threads Real time: 25.904657 s (since task start)
> 8 threads Real time: 20.090677 s (since task start)
> --------------------------------------------------------------------------------
> mmap_worker
> 1 threads Real time: 101.340662 s (since task start)
> 2 threads Real time: 51.484646 s (since task start)
> 4 threads Real time: 28.414534 s (since task start)
> 8 threads Real time: 21.785818 s (since task start)
>   


Try 16 threads, so that there is more contention on the read side as well.

Best regards,
--Edwin