New FreeBSD 5.3 e-mail server extremely slow - traced to getpwnam maybe ?

[Bruce Campbell]

Quoting Bruce Campbell <bruce at engmail.uwaterloo.ca>:
> Quoting Bruce Campbell <bruce at engmail.uwaterloo.ca>:
> > > On Tue, Jan 04, 2005 at 09:27:27PM -0500, Bruce Campbell wrote:
> > > 
> > > > I wrote a small program:
> > > > 
> > > >   #include <sys/types.h>
> > > >   #include <pwd.h>
> > > > 
> > > >   main( int argc, char *argv[] )
> > > >   {
> > > >   getpwuid( 13076 );
> > > >   }
> > > > 
> > > > and ran it under truss on 5.x and it generated 178,711 lines of output.
> > > > (the bulk of which is those lseek/read calls as above)
> 
> It looks like the overhaul of getpwent Apr/2003 to make it thread safe:
> 
>   http://www.freebsd.org/cgi/cvsweb.cgi/src/lib/libc/gen/getpwent.c
> 
> may be the problem.
> 
> I've tested the dbm_fetch function independently on a large
> file, and it is fine.
> 
> I've opened a bug report, and plan to build a replacement 4.x
> mail server, as the most deterministic path to restoring
> adequate e-mail service to our users.
> 
> Can anyone suggest a workaround ?

Well, somewhat unbelievably, copying a getpwent.c from 4.7
and remaking libc on 5.3 with it worked.  Load average
has gone from 70 to 2.

And, so that this qualifies as a question...

Am I crazy to pull an old getpwnam from 4.7 and blindly
build it on 5.3 ?

-- 
Bruce Campbell
Engineering Computing
CPH-2374B
University of Waterloo
(519)888-4567 ext 5889

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