Subject: Re: tsleep
To: None <>
From: Mirian Crzig Lennox <>
List: tech-kern
Date: 07/06/1999 14:31:15
Jason Thorpe <> writes:
> Um... It's NOT "two distinct symbol tables".

In most cases, it really is.  For example, in /sys/kern/vfs_subr.c we

In vinvalbuf():
    tsleep((caddr_t)bp, slpflag | (PRIBIO + 1), "vinvalbuf",lptimeo);

In vflushbuf():
    tsleep((caddr_t)&vp->v_numoutput, PRIBIO + 1, "vflushbuf", 0);

In vget():
    tsleep((caddr_t)vp, PINOD, "vget", 0);

In vgone():
    tsleep((caddr_t)vp, PINOD, "vgone", 0);

In effect, we're duplicating information that already exists in the
kernel symbol table.

If tsleep() were changed such that the calls could be:
    tsleep((caddr_t)bp, slpflag | (PRIBIO + 1), (caddr_t)vinvalbuf,lptimeo);

Then we'd get back 27 bytes "for free".  Maybe not a lot, but why
waste any space if you don't need to?  And in the aggregate, it could
easily be a few K of kernel mem.

Mirian Crzig Lennox                                Systems Anarchist
  "Don't follow leaders... watch the parking meters."  --Bob Dylan