anyone understand torvald's critique of freebsd?
tedm at toybox.placo.com
Mon Apr 24 10:19:37 UTC 2006
>From: Chuck Swiger [mailto:cswiger at mac.com]
>Sent: Saturday, April 22, 2006 7:51 PM
>To: Ted Mittelstaedt
>Subject: Re: anyone understand torvald's critique of freebsd?
>Ted Mittelstaedt wrote:
>> Then why does Linus think manipulating the VM page table mappings
>> is bad? That is, why does he -really- think it's bad, not the
>> publically-given reason? Is it because Linux is extrordinairly
>> inefficient in page table mappings due to some structural decision
>> that Linus made that cannot be reversed now, that it could never
>> be any good at it? Or is there some other reason?
>I can't speak with certainty as to what someone else might
>think; no doubt Linus
>is entirely capable of explaining his own position should you
>wish to inquire,
The guy is bitching about an option that's not even turned on,
thus it's not a legitimate criticism - there's an ulterior motive
somewhere. He isn't going to explain this of course - if he was
being honest he never would have bitched about it in the first place.
>I think Linus doesn't care much for Zero-copy sockets because
>for the common
>case of 1500/1504-byte MTU, you end up wasting at least 60% of
>a 4096-byte page
>for each packet, and maybe ?three? times that much if your
>hardware splits the
>packet into separate pages for the mbuf header, the packet
>headers, and the
ram is cheap these days.
I've seen things before that are a lot faster to do the memory-hogging
way. If this is one of these then the ram usage shouldn't be an
More information about the freebsd-questions