Linus vs. NVidia

[Robin Humble]

On Tue, Jun 19, 2012 at 04:50:48PM -0400, William Muriithi wrote:
>I just remembered something I did not understand and I am wondering if
>there is anyone here who can clarify what he meant.
>
>Someone had asked him if there was any other language other than C
>that can fit operating system development. He said no and he showed a
>couple of reasons why that is the case.  One of that case was the
>ability to optimize, as he can see the assembly lines that will be
>generated by just looking at the C code.  At that point he brought up
>a fact that Linux is the only language that can parse file without
>cache miss and apparently this has only been possible the last 18
>months.

here's a recent example of the micro-optimisations for pathname
checking he was referring to
  http://lwn.net/SubscriberLink/501492/3623664825cadb0f/

and I'm guessing a bit, but I think the '1000 core'(*) lookups in
parallel scalability that he "thought we'd never get there" is
probably the dentry scalabilty and lockless pagecache work done over
many years by (mostly) Nick Piggin
  https://lwn.net/Articles/419811/
  https://lwn.net/Articles/291826/

FYI, Linus's commits are
  http://git.kernel.org/?p=linux%2Fkernel%2Fgit%2Ftorvalds%2Flinux.git&a=search&h=HEAD&st=author&s=Linus+Torvalds
(hopefully someone smarter than me can figure out how to grep the
Merge's out and just show his own code?)

cheers,
robin

(*) currently only big ccNuma SGI machines, one day your cell phone?
--
The Toronto Linux Users Group.      Meetings: http://gtalug.org/
TLUG requests: Linux topics, No HTML, wrap text below 80 columns
How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists