Subject: Re: inn and mmap()ing the active file
To: None <current-users@NetBSD.ORG>
From: der Mouse <mouse@Collatz.McRCIM.McGill.EDU>
Date: 08/11/1995 10:54:56
> You need to add an msync() call to the INN code where it syncs the
> active file (don't remember where, exactly). The idiot INN author
Whatever else the INN author may be, he(?) isn't an idiot. Idiots
can't write code as good as that.
> refuses to put this into his code, because he says only "broken"
> systems need it,
I agree with him. If we didn't have the disintegrated buffer and VM
caches, we wouldn't need it either, because writes to the memory area
would change (and dirty) the buffer cache pages, thus (a) affecting
future filesystem reads immediately and (b) effecting a file write when
the buffer cache page eventually gets cleaned.
No, I think the INN author is entirely right on this one. NetBSD's
memory-mapping support is broken - not severely, but broken enough -
and it will stay that way until someone puts in the work necessary to
unify those silly caches.