lkml.org 
[lkml]   [2015]   [Oct]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH v2 00/36] x86: Rewrite all syscall entries except native 64-bit
On Oct 6, 2015 1:39 AM, "Linus Torvalds" <torvalds@linux-foundation.org> wrote:
>
> On Tue, Oct 6, 2015 at 1:47 AM, Andy Lutomirski <luto@kernel.org> wrote:
> >
> > The patchset is structured as a removal of the old fast syscall
> > code, then the change that makes syscalls into real functions, then
> > a clean re-implementation of fast syscalls.
> >
> > If we want some of the 25 cycles back, we could consider open-coding
> > a new C fast path.
>
> Ok, the 25 cycles are apparently just 12 cycles. Did you forget to
> update that after doing some of the optimizations - or is it 25 cycles
> on 64-bit and 12 cycles on 32-bit?

Forgot to update. I'll fix this in v3. I'll also re-benchmark on
native 32-bit, which is a bit easier now that I figured out why my
Debian VM couldn't do fast syscalls. (Hint: if you have a 32-bit
Debian or Debian-derived setup without libc6-i686 installed, install
it and everything works better.)

--Andy


\
 
 \ /
  Last update: 2015-10-06 20:41    [W:0.454 / U:1.004 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site