Subject: Re: kern/1515 [Re: PR-7148 (causes kernel panic)]
To: None <>
From: Manuel Bouyer <>
List: tech-net
Date: 11/07/1999 19:42:45
working on the RTM_IFINFO message I ran into a problem:
now the kernel will panic in rt_msg1() when trying to send a RTM_IFINFO
message, because the size of the message is greater than MHLEN when stats
are 64bit counters. On alpha, MSIZE is 256, on all others 128 (which means
sparc64 is probably brocken at this time :).
I can see 3 ways of solving this:
1) remove the stats from the RTM_IFINFO message. I wonder if any program
   use this part of the message but this breaks compatibility.
2) bump MSIZE to 256 on all port. I don't know what impact this will have
   on memory usage.
3) Define a new type (ifstat_t) which can be either 32 or 64 bit, defined
   per port in a machine-dependant header (which one ? machine/types.h ?).
   So we could keep 32 bit counters and MSIZE to 128 on machines with slow CPU
   or low memory and 64bit otherwise.

1) is probably evil. I would go for 2), given that even a vax can
stay up enouth to overflow 32 bit counters ... I think a vax is able to push
out 1G or data per week, isn't it ? This makes the counter overflow
after 4 weeks.

Comments ?

Manuel Bouyer <>