Re: Linux 2.4.17-rc1

[Roger Larsson <roger.larsson@skelleftea.mail.telia.com>]

On Thursday den 13 December 2001 21.44, Marcelo Tosatti wrote:
> Hi,
>
> I've just copied 2.4.17-rc1 to ftp.kernel.org... Its mirroring yet,
> probably.
>
> Well, I want people with the "unfreeable" buffer/cache problem to confirm
> with me that 2.4.17-rc1 is working ok.
>
> The same change which should fix that problem also should make 2.4 a bit
> less "swap happy".
>
>

Hi,

I have run some "files bigger than memory" (streaming) tests.
Some significant differences with earlier kernel:

* write - lowered throughput (26 MB/s => 22 MB/s)

* copy - throughput better by 2/3 (16 MB/s => 25 MB/s) !

* dbench 32 - back down to lower than 2.4.12 (due to increased fairness?)
	2.4.11				18.9 MB/s
	2.4.12				23.3 MB/s
	2.4.16				34.9 MB/s
	2.4.17-rc1			20.3 MB/s
	2.4.17-rc1 (file-readahead:1000)	24.5 MB/s
	[lets forget about them now...]

* diff - usage of "file-readahead" more than doubles efficency
	(most-kernels: 11 MB/s => 2.4.17-rc1 with readahead: 25 MB/s)

The nicest thing is that it is the first kernel where readahead tuning is not 
necessary for the copy operation.
Now it is only multiple-big-concurrent-reads that _needs_ "file-readahead"

/RogerL

-- 
Roger Larsson
Skellefteå
Sweden