Re: [patch] new-vm improvement [Re: 2.2.0 Bug summary]

Steve Bergman
1999-01-02T08:34:51Z

Linus Torvalds wrote:
>
> On Fri, 1 Jan 1999, Steve Bergman wrote:
> >
> > I got the patch and I must say I'm impressed. I ran my "117 image" test
> > and got these results:
> >
> > 2.1.131-ac11 172 sec (This was previously the best)
> > 2.2.0-pre1 + Arcangeli's 1st patch 400 sec
> > test1-pre + Arcangeli's 2nd patch 119 sec (!)
>
> Would you care to do some more testing? In particular, I'd like to hear
> how basic 2.2.0pre3 works (that's essentially the same as test1-pre, with
> only minor updates)? I'd like to calibrate the numbers against that,
> rather than against kernels that I haven't actually ever run myself.
>
> The other thing I'd like to hear is how pre3 looks with this patch, which
> should behave basically like Andrea's latest patch

Hi Linus,

Andrea sent another patch to correct a problem with i/o bound processes,
which he also posted to linux-kernel. The performance in this test is
unchanged.

Here are the results:

2.1.131-ac11 172 sec

2.2.0-pre1 + Arcangeli's 1st patch 400 sec
test1-pre + Arcangeli's 2nd patch 119 sec
test1-pre + Arcangeli's 3rd patch 119 sec
test1-pre + Arcangeli's 3rd patch 117 sec
(changed to priority = 9 in mm/vmscan.c)

2.2.0-pre3 175 sec
2.2.0-pre3 + Linus's patch 129 sec

RH5.2 Stock (2.0.36-0.7) 280 sec

I noticed that in watching the 'vmstat 1' during the test that
'2.2.0+Linus patch' was not *quite* as smooth as the Archangeli patches,
in that there were periods of 2 or 3 seconds in which the swap out rate
would fall to ~800k/sec and then jump back up to 1.8-2.5MB/sec. I have
only run your patch once though. I'll check it further tomorrow to
confirm that that is really the case. Note how much better 2.2 is doing
compared to 2.0.36-0.7 in this situation.

I should be available for a good part of this weekend for further
testing; Just let me know.

As a reference:

AMD K6-2 300
128MB ram
2GB seagate scsi2 dedicated to swap
Data drive is 6.5GB UDMA

Steve Bergman
steve@netplus.net