2011/9/1 Ivan Voras <[email protected]>: > On 1 September 2011 16:11, Attilio Rao <[email protected]> wrote: > >>> I mean, if we have 2 cpus in a machine, but MAXCPU is set to 256, there >>> is a bunch of "lost" memory and higher levels of lock contention? >>> >>> I thought that attilio was taking a stab at enhancing this, but at the >>> current time anything more than a value of 64 for MAXCPU is kind of a >>> "caveat emptor" area of FreeBSD. >> >> With newest current you can redefine MAXCPU in your kernel config, so >> you don't need to bump the default value. >> I think 64 as default value is good enough. >> >> Removing MAXCPU dependency from the KBI is an important project >> someone should adopt and bring to conclusion. > > That's certainly one half of it and thanks for the work, but the real > question in this thread is what Sean asked: what are the negative > side-effects of simply bumping MAXCPU to 256 by default? AFAIK, there > are not that many structures which are statically sized by MAXCMPU and > most use the runtime-detected smp_cpus? >
Well, there are quite a few statically allocated, but as I said, making the kernel MAXCPU-agnostic (or sort of agnostic) is a goal and a good project. Thanks, Attilio -- Peace can only be achieved by understanding - A. Einstein _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[email protected]"
