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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Brough, Tom wrote: > > IIRC HP-UX had a feature that uses (or used to use) sticky bit on executables to keep them > in memory even when nobody is using it. Urm scratched head..... shared libraries maybe, I don't think the address space was shared/sharable for executable code but shared libraries had to use position independent code.... But my recollection is a bit vague. The only thing I remember clearly was the way the HP-UX boxes crashed and burned when we were trying out funky optimisations like these. HP-UX doesn't often crash, so when it happens it tends to stick in your mind. They had an option for paging out, rather than discarding NFS loaded code pages as well. The idea being rereading code from the NFS server might be slower than local swap access. I suspect we were playing with both these when the boxes were crashing... it was a little while before I realised it was the combination of synchronous I/O and NFS, that was causing the worst performance problems (HP-UX NFS write performance - test it if it is important to you). I learnt a lot about HP-UX I/O sorting that beastie out. I also learnt not to fiddle with funky sounding opimisations that aren't widely used unless you're absolutely sure you need those last few percentage points of performance. Simon -----BEGIN PGP SIGNATURE----- Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQE/ITm6GFXfHI9FVgYRAvF8AJ9LT3FsrBV+XThODYL2Iru3BE/OrQCgvJ2C g0WKOC8br17jVWVjBBLD90g= =MyXM -----END PGP SIGNATURE----- -- The Mailing List for the Devon & Cornwall LUG Mail majordomo@xxxxxxxxxxxx with "unsubscribe list" in the message body to unsubscribe.