Linux-kernel mailing list archive 1999-34,: Re: Streaming disk I/O kills file buffering and makes Linux unusable

# Re: Streaming disk I/O kills file buffering and makes Linux unusable

Benno Senoner (sbenno@gardena.net)
Mon, 23 Aug 1999 23:54:07 +0200

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On Mon, 23 Aug 1999, Andrea Arcangeli wrote:
> On Mon, 23 Aug 1999, Benno Senoner wrote:
>
> >No , I'm not saying that there is a bug, I'm saying that the
> >filebuffering works very well in almost all cases , except of reading large
> >files from disk continuously.
>
> Could you check `vmstat 1` and verify if you have continous
> swapin/swapout? (I bet yes) If I am right then you'll probably want to
> apply this my patch and try again and notice the performance difference
> with eyes.
>
> ftp://ftp.suse.com/pub/people/andrea/kernel-patches/my-2.2.12-final3/no-swapout-2.2.10-B
>
> Andrea

No , have very little swapin/swapouts (only occasionally) when clicking on the
xterm icon.
Since I run on a 256MB RAM box, I have to wait 30-40sec for the xterm
executable disappearing from buffers ( since I stream about 5MB/sec).
After this time when I must wait up to 5-6sec from clicking to the icon to the
actual launch of the xterm.
Of course this is because the disk is under high load , and loads the
executable slowly, but if I I click on the icon again after only a few secs
(instead of waiting 30-40secs) the 2nd xterm starts up almost immediately since
it's still cached, 200MB filebuffer buffer/5MB/sec = takes about 40secs to fill
all buffers.

Browsing the web while runnig the streaming app, becomes frustrating because
you have no caching at all while working on a very slow disk (due to disk I/O).
IMHO with direct I/O the rest of the system will remain quite snappy.

regards,
Benno.

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- Next message: Kevin Kunzelman: "Re: ISSUE: Writing to mmap creates duplicate pages in 2.2.5 and 2.2.11 kernels"
- Previous message: Andrea Arcangeli: "[patch] SA_INTERRUPT broken for SA_SHIRQ"
- Maybe in reply to: Benno Senoner: "Streaming disk I/O kills file buffering and makes Linux unusable"
- Next in thread: Andrea Arcangeli: "Re: Streaming disk I/O kills file buffering and makes Linux unusable"
- Next in thread: Florian Weimer: "Re: Streaming disk I/O kills file buffering and makes Linux unusable"
- Reply: Andrea Arcangeli: "Re: Streaming disk I/O kills file buffering and makes Linux unusable"