cvs commit: src/sys/vm vm_kern.c

M. Warner Losh imp at bsdimp.com
Mon Feb 16 13:23:16 PST 2004


In message: <20040216120153.S80753 at pooker.samsco.home>
            Scott Long <scottl at FreeBSD.org> writes:
: On Mon, 16 Feb 2004, Robert Watson wrote:
: >
: > On Mon, 16 Feb 2004, Dag-Erling Smorgrav wrote:
: >
: > >   Log:
: > >   Don't panic if we fail to satisfy an M_WAITOK request; return 0 instead.
: > >   The calling code will either handle that gracefully or cause a page fault.
: >
: > Also, this turns an easily understood and widely documented kernel panic
: > message into a page fault.  Prior to this, users could google for the
: > message and find documentation on increasing the size of the kernel
: > address space.  Now, it requires facility with the source code in order to
: > figure out what it is going on (since the page fault trace won't include
: > the memory allocation).
: >
: 
: Agreed on all points.  I thought that there was along discussion on this
: in the last 1-2 weeks and that all of these issues were brought up.
: Please back this out, and lets focus on getting the sematics that you need
: for procfs rather than just ruining the sematics for everything else.

Please back this out.  We worked for a long time to make M_WAITOK mean
that the return value is never null.

Warner


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