CVS commit: src/sys/netinet

[Thor Lancelot Simon <tls%netbsd.org@localhost>]

Module Name:    src
Committed By:   tls
Date:           Wed Mar 31 07:31:15 UTC 2010

Modified Files:
        src/sys/netinet: ip_input.c

Log Message:
Don't hold kernel lock across call to ip_input() -- it blocked *all*
hardware interrupts for the length of time it took for all dequeued
packets to flow up the stack (on multiprocessors only).  Initial testing
shows performance impact is minimal -- since this temporary fix actually
means taking/releasing the kernel lock per-packet, that seems
acceptable.

Holding the kernel lock across the ip_input() call duplicated the
exclusion intended to be provided by the socket locks/softnet lock
(same lock, for INET/INET6 sockets) and could mask serious bugs.  Several
hours' testing didn't turn any up but I'd be surprised if some don't now
appear.

Damon Permezel noticed the problem.  Temporary fix suggested by matt@.


To generate a diff of this commit:
cvs rdiff -u -r1.284 -r1.285 src/sys/netinet/ip_input.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.