Date: Mon, 2 Jun 1997 09:09:32 -0700 (MST) From: Terry Lambert <terry@lambert.org> To: tom@sdf.com (Tom Samplonius) Cc: terry@lambert.org, jkh@time.cdrom.com, hackers@FreeBSD.ORG Subject: Re: LINT and GENERIC - between a rock and a generic place. Message-ID: <199706021609.JAA14593@phaeton.artisoft.com> In-Reply-To: <Pine.BSF.3.95q.970531173527.5274A-100000@misery.sdf.com> from "Tom Samplonius" at May 31, 97 05:41:18 pm
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> > Jordan is speaking to hard limits. The login.conf speaks to soft > > limits, and is still limited to what it can set by the hard limits. > > Well, login.conf does allow you set hard and soft limits, at least in > the language of setrlimit() A hard limit is a limit imposed by system limits. A quota limit is a limit imposed by the system on a particular user. A soft limit or "working set" is the limit imposed on the user by himself, or by his acceptance of less-than-quota-limit defaults for soft limits. It's not my fault that the man pages don't make the distinction so that it's clear that a kernel recompile is needed to raise quota limits above hard limits. Talk to the documentation people. > > The hard limits are the result of static allocations, general at > > initialization time before the kernel is really running, like > > globally declared arrays. > > The only two things I can think of is the maximum number of open files, > and mbufs clusters. > > Why can't these be handled like setting device setttings (IRQs, > baseports, etc)? Boot with a "-c" to change them, before the kernel is > really running, and then write the changes into kernel after boot with > dset. Because they are used as static initializers in the code; the areas are not allocated so much as they are staked out in the kernel data segment via declaration. It is somewhat faster to reference a statically declared area (no pointer dereference). I think the utility outweighs the penalty, however. > > AIX was probably right when it made all this stuff dynamic. Then you > > could at least sysctl the "hard limit" after the machine was up. > > I guess there is performance penalty? Additional pointer dereference per access (as above). Regards, Terry Lambert terry@lambert.org --- Any opinions in this posting are my own and not those of my present or previous employers.
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