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From Dan Kegel <d...@alumni.caltech.edu>
Subject Re: fix for hybrid server problems.
Date Mon, 17 May 1999 13:53:16 GMT
Vivek Sadananda Pai wrote:
> On Sun, 9 May 1999, Dean Gaudet <dgaudet@arctic.org> wrote:
> > So far my largest concern, which is the same as my concern with entirely
> > select-based servers, is disk i/o.  This all works wonderfully if you
> > rarely have to page from disk.  But for servers with large working sets,
> > aggregating like this hurts because you have only a single i/o request
> > outstanding at a time... with multiple processes we alleviate some of this
> > problem... there are probably other options...
> 
> I found two problems with purely select-based servers with regard to
> having only a disk single I/O available. The first, of course, is that
> you can't parallelize disk accesses (scheduling or multiple disks),
> but more importantly, while the process is blocked, no other
> user-level processing occurs.

No need for a second process on those OS's that support sendfile(),
I think, 'cause then the disk I/O is done in the background for
you by the kernel.
(Cool, another reason to try sendfile()!)
- Dan

(p.s. Sorry if this was a repost.)

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