Re: Performance

>[mirian@cosmic.com (Mirian Crzig Lennox) writes:]
>
> >Linux gets a lot of its superior subjective performance from the fact
> >that it caches disk writes so aggressively. VSTa, on the other hand,
>always
> >tries to keep the disk in sync.
>
>This is true... it really costs quite a bit of performance. But as an OS
>experimenter, I find the hardness of the filesystem to be well worth the
>slowdown on the occasional bulk data operations I do.

I see your point.

>One other thing to note is that when doing "tar -z..." operations, you're
>going through a pipe server which does very, very little buffering.

I figured alot of it had to do with the piping system in VSTa more than
anything else. I hadn't considered the disk caching though.

>An
>interesting project for somebody would be to revisit this design aspect of
>VSTa pipes. Right now the pipe server doesn't maintain a private copy of
>the data (it blocks the writer until it can point the reader's I/O vectors
>directly at the writer's data). This is cool, and shows the flexibility of
>vectored I/O messages, but I suspect in the big picture it'd be better for
>the pipe server to buffer quite a bit of data, to permit more concurrency
>between reader and writer.
>
> >>Also, untarring and gunzipping the vsta_src.tz file never finishes. It
> >>always prematurely exits with a 'broken pipe' error.
>
>It probably finished OK... Dave Hudson made the pipe server play with
>compressed tar. But it has seemed like there's a race condition in there
>somewhere. The few times I've looked, the final file of the archive had
>been extracted OK, and thus I never gave much priority to fixing that
>spurious error message.
>
>Andy Valencia

I'm not sure since I don't know what the last file was. I'll try creating my
own tarred, gzipped files and see what happens. The curious thing is, it
only happens sometimes. If, as the previous person mentioned, it's because
of an EOF on the pipe, then it would happen for every pipe, but it doesn't.
It just happens on the larger archives. I'll do a little more testing.

Thanks for all your help and suggestions! :-)

Sincerely,
Sandro
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Received on Mon Dec 25 12:52:20 2000