From: Ralf Baechle <ralf@linux-mips.org>
To: Jeffrey Baitis <baitisj@evolution.com>
Cc: linux-mips@linux-mips.org, Adam_Kiepul@pmc-sierra.com,
"Mr. Brian R. Gunnison" <brian@evolution.com>,
Francis Yu <francisyu@synergyrep.com>,
Johnny Lam <Johnny_Lam@pmc-sierra.com>
Subject: Re: Newbie R5K questions -- -mips2 vs -mips4; is n32 ABI supported by Linux?
Date: Mon, 17 Nov 2003 23:52:48 +0100 [thread overview]
Message-ID: <20031117225248.GA15868@linux-mips.org> (raw)
In-Reply-To: <1069106666.1829.323.camel@powerpuff.evo1.pas.lab>
On Mon, Nov 17, 2003 at 02:04:26PM -0800, Jeffrey Baitis wrote:
> I'm currently trying to increase performance on our PMC-Sierra RM5231
> system by taking advantage of the MIPS IV ISA. This processor has a
> 32-bit address bus interface with 64-bit GPRs, so I guess that the
> choice of -mabi=n32 is ideal for this processor.
In addition to what Daniel just said ...
N32 requires a 64-bit kernel to run on which is significantly larger
thereby causing more cache misses so a 64-bit kernel is often slower.
On the kernel side a 64-bit kernel is drastically better at handling
large amounts of memory, so once a 32-bit kernel needs highmem the
64-bit kernel will win the race. Often these effects influence
performance more than what you might gain from exploiting a new ISA.
Ralf
prev parent reply other threads:[~2003-11-17 22:53 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-11-17 22:04 Newbie R5K questions -- -mips2 vs -mips4; is n32 ABI supported by Linux? Jeffrey Baitis
2003-11-17 22:29 ` Daniel Jacobowitz
2003-11-17 22:52 ` Ralf Baechle [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20031117225248.GA15868@linux-mips.org \
--to=ralf@linux-mips.org \
--cc=Adam_Kiepul@pmc-sierra.com \
--cc=Johnny_Lam@pmc-sierra.com \
--cc=baitisj@evolution.com \
--cc=brian@evolution.com \
--cc=francisyu@synergyrep.com \
--cc=linux-mips@linux-mips.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.