Skip site navigation (1)Skip section navigation (2)
Date:      Wed, 1 Oct 2003 04:40:34 -0400 (EDT)
From:      Jeff Roberson <jroberson@chesapeake.net>
To:        Alan Cox <alc@cs.rice.edu>
Cc:        cvs-all@FreeBSD.org
Subject:   Re: cvs commit: src/sys/i386/i386 support.s src/sys/i386/include md_var.h
Message-ID:  <20031001043125.P99666-100000@mail.chesapeake.net>
In-Reply-To: <20031001082834.GT20747@cs.rice.edu>

next in thread | previous in thread | raw e-mail | index | archive | help
On Wed, 1 Oct 2003, Alan Cox wrote:

> On Wed, Oct 01, 2003 at 01:39:03AM -0400, Jeff Roberson wrote:
> > This moves data 3.8x faster than bzero on my laptop.  In a moment I will
> > commit pmap bits to make use of it.  This improved my 'make kernel' times
> > by almost 2%.  It will do even better in workloads that demand a lot of
> > zero pages.
> >
>
> An sfence at the end of sse2_pagezero() is probably prudent.
>
> Alan

Thanks.  I misunderstood the manual the first time and thought it was only
necessary if the memory was accessed using different MTRR types.

>
> > On Tue, 30 Sep 2003, Jeff Roberson wrote:
> >
> > > jeff        2003/09/30 22:25:27 PDT
> > >
> > >   FreeBSD src repository
> > >
> > >   Modified files:
> > >     sys/i386/i386        support.s
> > >     sys/i386/include     md_var.h
> > >   Log:
> > >    - Add ss2_pagezero() for zeroing pages using the movnti instruction.  This
> > >      instruction is enabled with SSE2 but does not use SSE registers.  It is a
> > >      "non-temporal" move which bypasses the cache and does not dirty lines.
> > >
> > >   Revision  Changes    Path
> > >   1.98      +14 -0     src/sys/i386/i386/support.s
> > >   1.65      +1 -0      src/sys/i386/include/md_var.h
> > >
>



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20031001043125.P99666-100000>