Re: zmailer getpw* routines

[Felix Lee <flee@guardian.cs.psu.edu>]

Guy Middleton:
> Is it really "handled elsewhere"?

No.  The worst case behavior is always triggered by
	$(homedirectory "$user")
This always does a linear search, which is especially awful if you're
using YP.  This is the single slowest part of routing a local user.

The real problem is interaction between the router's memory-allocation
pattern and some implementations of malloc.  Calling getpwnam() is
going to call fopen/fclose, which is going to malloc/free an 8k
buffer.  The 8k chunk is later split to satisfy some other malloc
request, which means the next time you call getpwnam() you need
*another* 8k buffer.  Your data segment slowly grows without bound,
until you're out of vm.

You can avoid this problem by using a malloc that never splits chunks,
like the BSD/Caltech malloc.
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