httpd-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Rodent of Unusual Size <Ken.C...@Golux.Com>
Subject Re: some reasons why Apache 2.0 threaded is slower than prefork
Date Thu, 01 Mar 2001 20:42:54 GMT
Cliff Woolley wrote:
> It's the "lock-free operations" part that I've been stumbling over
> so far.

OpenVMS on the VAX dealt with this by using the low bit of the
pointer as a lock.  Blocks were always 64-bit aligned, so it
was free.  They used interlocked instructions that were guaranteed
atomic:  BBSSI (branch on bit set and set, interlocked) and BBCCI.
I do not know how we could use that here, but it was simple and
elegant.. thread, process, and SMP safe.
#ken    P-)}

Ken Coar                    <http://Golux.Com/coar/>
Apache Software Foundation  <>
"Apache Server for Dummies" <http://Apache-Server.Com/>
"Apache Server Unleashed"   <http://ApacheUnleashed.Com/>

ApacheCon 2001!
Four tracks with over 70+ sessions. Free admission to exhibits
and special events - keynote presentations by John 'maddog' Hall
and David Brin. Special thanks to our Platinum Sponsors IBM and
Covalent, Gold Sponsor Thawte, and Silver Sponsor Compaq.  Attend
only Apache event designed and fully supported by the members of
the ASF. See more information and register at <http://ApacheCon.Com/>!

View raw message