From: Greg Ungerer <gerg@snapgear.com>
To: "Robert P. J. Day" <rpjday@crashcourse.ca>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Linux-Arch <linux-arch@vger.kernel.org>
Subject: Re: should there still be arch-specific 4KSTACKS support?
Date: Fri, 29 Jun 2012 16:10:42 +1000 [thread overview]
Message-ID: <4FED46E2.3070008@snapgear.com> (raw)
In-Reply-To: <CAMuHMdXqieWY5C_C9ituryRwPSNDU__XL8X=g6EXF3-RH1DDdw@mail.gmail.com>
On 24/06/12 04:51, Geert Uytterhoeven wrote:
> Broadening the audience...
>
> On Sat, Jun 23, 2012 at 5:47 PM, Robert P. J. Day <rpjday@crashcourse.ca> wrote:
>> via some convoluted logic, i ended up doing the following search:
>>
>> $ grep -r 4KSTACKS *
>> arch/sh/configs/r7785rp_defconfig:CONFIG_4KSTACKS=y
>> arch/sh/Kconfig.debug:config 4KSTACKS
>> arch/sh/include/asm/thread_info.h:#if defined(CONFIG_4KSTACKS)
>> arch/mn10300/include/asm/thread_info.h:#ifdef CONFIG_4KSTACKS
>> arch/m68k/Kconfig.machine:config 4KSTACKS
>> arch/m68k/configs/m5208evb_defconfig:# CONFIG_4KSTACKS is not set
>> arch/m68k/configs/m5275evb_defconfig:# CONFIG_4KSTACKS is not set
>> arch/m68k/configs/m5475evb_defconfig:# CONFIG_4KSTACKS is not set
>> arch/m68k/include/asm/thread_info.h:#ifdef CONFIG_4KSTACKS
>> arch/c6x/include/asm/thread_info.h:#ifdef CONFIG_4KSTACKS
>> drivers/lguest/interrupts_and_traps.c: * Depending on the CONFIG_4KSTACKS option, the Guest can have one or
>> kernel/lockdep.c: * hardirq contexts (such as on 4KSTACKS), so only
>> $
>>
>> so even though 4KSTACKS support was officially removed in June of
>> 2010:
>>
>> $ git show dcfa7262
>>
>> there's still traces of it, some of it obviously harmless, leftover
>> cruft, but it would appear that both sh and m68k still provide a
>> 4KSTACKS config option.
>>
>> how much of that can be tossed as useless?
Well, it still works on non-mmu m68k. Yes, I am aware of the issues,
but for those types of small memory non-mmu systems 4k stacks is a
saving. And those types of systems don't tend to use the parts of
the kernel that have been known to want lots of kernel stack.
But if opposition was incredibly strong to having anything support
4k stacks, I probably won't loose any sleep over it being removed
for m68k.
Regards
Greg
------------------------------------------------------------------------
Greg Ungerer -- Principal Engineer EMAIL: gerg@snapgear.com
SnapGear Group, McAfee PHONE: +61 7 3435 2888
8 Gardner Close FAX: +61 7 3217 5323
Milton, QLD, 4064, Australia WEB: http://www.SnapGear.com
prev parent reply other threads:[~2012-06-29 6:12 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <alpine.DEB.2.02.1206231142150.14887@oneiric>
2012-06-23 18:51 ` should there still be arch-specific 4KSTACKS support? Geert Uytterhoeven
2012-06-29 6:10 ` Greg Ungerer [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=4FED46E2.3070008@snapgear.com \
--to=gerg@snapgear.com \
--cc=geert@linux-m68k.org \
--cc=linux-arch@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=rpjday@crashcourse.ca \
/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;
as well as URLs for NNTP newsgroup(s).