Messages in this thread | | | Subject | Re: -rt doesn't compile for UML | From | Miklos Szeredi <> | Date | Wed, 28 Nov 2007 16:35:12 +0100 |
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> > When writing a big file to a ubd disk, everything in uml slows down to > > a crawl, even though CPU usage is minimal. > > What exactly is your test case?
Something like:
dd if=/host/tmp/bigfile of=/tmp/bigfile bs=1048576 count=100
and run 'top' or 'watch something' in another terminal, which sometimes completely stops updating during the write.
> I have some patches which theoretically should help I/O performance > which I've been sitting on because I can't find a case where they > help.
It's not I/O performance I'm worried about, but scheduling latencies. CPU use inside and outside the UML is minimal, so I can't see where this slowdown comes from.
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