Linux MIPS Architecture development
 help / color / mirror / Atom feed
From: Ralf Baechle <ralf@linux-mips.org>
To: "Kevin D. Kissell" <kevink@mips.com>
Cc: Franck Bui-Huu <vagabon.xyz@gmail.com>,
	Andrew Haley <aph-gcc@littlepinkcloud.com>,
	David Daney <ddaney@avtrex.com>,
	linux-mips@linux-mips.org,
	Richard Sandiford <rsandifo@nildram.co.uk>,
	gcc@gcc.gnu.org
Subject: Re: Cannot unwind through MIPS signal frames with ICACHE_REFILLS_WORKAROUND_WAR
Date: Tue, 13 Nov 2007 15:08:20 +0000	[thread overview]
Message-ID: <20071113150820.GB6582@linux-mips.org> (raw)
In-Reply-To: <019e01c82602$f5463bf0$10eca8c0@grendel>

On Tue, Nov 13, 2007 at 03:37:39PM +0100, Kevin D. Kissell wrote:

> True, though it should perhaps be noted that currently it's only on 4KSc/Sd
> systems (which I know you work on) where it's even possible for the stack
> *not* to have exec permissions, since the classical MIPS MMU gives
> execute permission to any page that is readable.

Disabling PROT_EXEC on a mapping tells the kernel it doesn't need to take
care of I-cache coherency.  So it's somewhat beneficial even in absence of
a protection bit in the actual TLB hardware.

Some of these performance optimizations are impossible because the kernel
can't have definate knowledge that certain addresses have never entered the
I-cache.

  Ralf

  parent reply	other threads:[~2007-11-13 15:11 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-11-13  7:52 Cannot unwind through MIPS signal frames with ICACHE_REFILLS_WORKAROUND_WAR David Daney
2007-11-13 11:48 ` Andrew Haley
2007-11-13 12:10   ` Ralf Baechle
2007-11-13 13:14     ` Franck Bui-Huu
2007-11-13 14:00       ` Ralf Baechle
2007-11-13 14:22         ` Franck Bui-Huu
2007-11-13 15:01           ` Ralf Baechle
2007-11-13 22:11             ` Andrew Pinski
2007-11-13 14:37       ` Kevin D. Kissell
2007-11-13 14:37         ` Kevin D. Kissell
2007-11-13 14:49         ` Franck Bui-Huu
2007-11-13 15:08         ` Ralf Baechle [this message]
2007-11-13 22:49           ` Cannot unwind through MIPS signal frames withICACHE_REFILLS_WORKAROUND_WAR Kevin D. Kissell
2007-11-13 22:49             ` Kevin D. Kissell
2007-11-13 21:26       ` VDSO on mips (was Re: Cannot unwind through MIPS signal frames with ICACHE_REFILLS_WORKAROUND_WAR) Franck Bui-Huu
2007-11-15  8:46     ` Cannot unwind through MIPS signal frames with ICACHE_REFILLS_WORKAROUND_WAR Franck Bui-Huu
2007-11-15 11:53       ` Ralf Baechle
2007-11-15 17:21         ` David Daney
2007-11-17  8:38           ` Franck Bui-Huu
2007-11-13 16:12 ` David Daney

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=20071113150820.GB6582@linux-mips.org \
    --to=ralf@linux-mips.org \
    --cc=aph-gcc@littlepinkcloud.com \
    --cc=ddaney@avtrex.com \
    --cc=gcc@gcc.gnu.org \
    --cc=kevink@mips.com \
    --cc=linux-mips@linux-mips.org \
    --cc=rsandifo@nildram.co.uk \
    --cc=vagabon.xyz@gmail.com \
    /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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox