From: "Nigel Roles" <nigel@9fs.org>
To: <9fans@cse.psu.edu>
Subject: RE: [9fans] Threads: Sewing badges of honor onto a Kernel
Date: Sat, 28 Feb 2004 18:16:50 +0000 [thread overview]
Message-ID: <001d01c3fe27$09478e90$2bdcfea9@blue> (raw)
In-Reply-To: <20040228141458.GD16357@parcelfarce.linux.theplanet.co.uk>
9fans-admin@cse.psu.edu wrote:
> Subject: Re: [9fans] Threads: Sewing badges of honor onto a Kernel
>
>
> On Sat, Feb 28, 2004 at 01:40:48PM -0000, Nigel Roles wrote:
>> Whilst writing the email, it occurred to me that you could
>> probably pull stunts with mmap/mremap and catching signals,
>> and get what is wanted.
>
> mmap(2)
> MAP_GROWSDOWN
> Used for stacks. Indicates to the kernel VM system that
> the map- ping should extend downwards in memory.
>
> See mm/mmap.c:expand_stack() for details.
>
> So no signals involved and that's precisely what is used for stack
> anyway - anonymous VM_GROWSDOWN mapping.
>
> Note: from my reading of the calc_vm_flag_bits() there is a problem on
> parisc, what with the stack growing up - no way to get VM_GROWSUP from
> mmap() and that's what would be needed to act as stacks there. For
> that matter, parisc do_page_fault() looks fishy in that area, but I'm
> not familiar enough with that platform.
Fair point; I had missed the utility of MAP_ANON.
So there it is, Martin. Near enough the same semantics.
It's not pretty, and not obvious, but equivalent. With a helper
function it could be transparent to the user level (i.e. as
easy to deploy as rfork()), and apparently more MMU efficient.
I say apparently because I don't feel qualified to judge.
The question is, does this make Linux 'right' and Plan 9 'wrong',
which was quite a bit of what touched off the thread?
Neither, I would have thought.
next prev parent reply other threads:[~2004-02-28 18:16 UTC|newest]
Thread overview: 191+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-02-27 4:45 dbailey27
2004-02-27 5:05 ` Scott Schwartz
2004-02-27 5:06 ` andrey mirtchovski
2004-02-27 5:05 ` dbailey27
2004-02-27 5:26 ` Rob Pike
2004-02-27 5:37 ` dbailey27
2004-02-27 5:47 ` ron minnich
2004-02-27 7:43 ` boyd, rounin
2004-02-27 5:54 ` Rob Pike
2004-02-27 6:01 ` dbailey27
2004-02-29 21:14 ` boyd, rounin
2004-03-01 4:40 ` Kenji Okamoto
2004-02-27 5:06 ` dbailey27
2004-02-27 5:28 ` Rob Pike
2004-02-27 6:19 ` Scott Schwartz
2004-02-28 9:38 ` Bruce Ellis
2004-02-28 10:10 ` Charles Forsyth
2004-02-28 10:28 ` Bruce Ellis
2004-02-28 10:11 ` [9fans] limbo? David Tolpin
2004-02-28 10:22 ` Geoff Collyer
2004-02-28 19:27 ` Charles Forsyth
2004-02-28 21:16 ` Russ Cox
2004-02-28 13:28 ` [9fans] Threads: Sewing badges of honor onto a Kernel boyd, rounin
2004-02-29 20:59 ` boyd, rounin
2004-02-27 5:43 ` ron minnich
2004-02-27 5:50 ` George Michaelson
2004-02-27 5:59 ` ron minnich
2004-02-27 6:07 ` George Michaelson
2004-02-27 7:47 ` boyd, rounin
2004-02-27 6:20 ` [9fans] " Linus Torvalds
2004-02-27 6:31 ` dbailey27
2004-02-27 6:49 ` Linus Torvalds
2004-02-27 6:48 ` dbailey27
2004-02-27 7:04 ` Linus Torvalds
2004-02-27 7:06 ` dbailey27
2004-02-27 7:30 ` a
2004-02-27 7:49 ` dbailey27
2004-02-27 7:39 ` Lucio De Re
2004-02-27 7:57 ` Linus Torvalds
2004-02-27 8:00 ` Rob Pike
2004-02-27 8:05 ` Lucio De Re
2004-02-27 8:06 ` boyd, rounin
2004-02-27 7:47 ` Linus Torvalds
2004-02-27 7:46 ` dbailey27
2004-02-27 8:08 ` Linus Torvalds
2004-02-27 8:04 ` dbailey27
2004-02-27 8:19 ` Geoff Collyer
2004-02-27 15:28 ` Rob Pike
2004-02-27 16:57 ` Linus Torvalds
2004-02-27 8:11 ` Lucio De Re
2004-02-27 8:17 ` Rob Pike
2004-02-27 8:31 ` Lucio De Re
2004-02-27 9:46 ` Linus Torvalds
2004-02-27 8:44 ` boyd, rounin
2004-02-27 10:00 ` Linus Torvalds
2004-02-27 9:52 ` Lucio De Re
2004-02-27 10:00 ` Charles Forsyth
2004-02-27 10:07 ` Lucio De Re
2004-02-27 10:14 ` Charles Forsyth
2004-02-27 10:24 ` Lucio De Re
2004-02-27 11:40 ` C H Forsyth
2004-02-28 9:58 ` Bruce Ellis
2004-02-27 10:11 ` Linus Torvalds
2004-02-27 10:13 ` Lucio De Re
2004-02-27 10:36 ` Linus Torvalds
2004-02-27 19:07 ` Donald Brownlee
2004-02-27 7:47 ` Fco.J.Ballesteros
2004-02-27 8:04 ` boyd, rounin
2004-02-29 21:17 ` boyd, rounin
2004-02-27 7:12 ` Rob Pike
2004-02-27 7:17 ` Charles Forsyth
2004-02-27 8:01 ` boyd, rounin
2004-02-27 8:06 ` Scott Schwartz
2004-02-27 8:15 ` Rob Pike
2004-02-27 7:06 ` Lucio De Re
2004-02-27 7:53 ` boyd, rounin
2004-02-27 12:23 ` Dave Lukes
2004-02-27 16:08 ` Linus Torvalds
2004-02-27 16:39 ` Dave Lukes
2004-02-27 17:05 ` Linus Torvalds
2004-02-27 17:03 ` Fco.J.Ballesteros
2004-02-27 17:50 ` Dave Lukes
2004-02-27 18:26 ` Linus Torvalds
2004-02-27 18:27 ` matt
2004-02-27 18:39 ` andrey mirtchovski
2004-02-27 23:39 ` boyd, rounin
2004-03-01 8:44 ` Fco.J.Ballesteros
2004-03-01 8:48 ` Fco.J.Ballesteros
2004-03-01 8:59 ` Lucio De Re
2004-03-01 9:04 ` Fco.J.Ballesteros
2004-03-01 9:16 ` Kenji Okamoto
2004-03-01 9:19 ` Kenji Okamoto
2004-03-01 15:47 ` ron minnich
2004-03-01 16:23 ` lucio
2004-03-01 18:04 ` viro
2004-03-02 9:37 ` Douglas A. Gwyn
2004-03-02 10:16 ` lucio
2004-03-03 1:36 ` Kenji Okamoto
2004-03-02 1:40 ` rob pike, esq.
2004-02-27 23:20 ` boyd, rounin
2004-03-01 10:34 ` Bengt Kleberg
2004-03-01 14:40 ` Russ Cox
2004-03-01 15:17 ` boyd
2004-03-02 9:42 ` Bengt Kleberg
2004-03-02 9:53 ` Fco.J.Ballesteros
2004-03-02 14:51 ` ron minnich
2004-03-03 9:33 ` Bengt Kleberg
2004-03-03 12:59 ` ron minnich
2004-03-03 13:10 ` Fco.J.Ballesteros
2004-03-03 13:21 ` ron minnich
2004-03-04 10:00 ` Yi Li
2004-03-04 11:22 ` Fco.J.Ballesteros
2004-03-05 15:17 ` Yi Li
2004-03-03 13:38 ` rog
2004-03-03 17:57 ` a
2004-03-01 15:56 ` ron minnich
2004-03-02 9:42 ` Bengt Kleberg
2004-02-27 17:32 ` C H Forsyth
2004-02-29 21:10 ` boyd, rounin
2004-03-01 8:19 ` Charles Forsyth
2004-03-01 8:46 ` dbailey27
2004-03-01 9:34 ` David Tolpin
2004-03-01 10:02 ` Charles Forsyth
2004-03-01 10:12 ` David Tolpin
2004-03-01 10:40 ` Charles Forsyth
2004-03-01 11:56 ` David Tolpin
2004-03-01 17:29 ` rog
2004-03-02 6:38 ` 9nut
2004-03-01 19:02 ` Taj Khattra
2004-03-01 19:15 ` David Tolpin
2004-03-01 19:22 ` Joel Salomon
2004-03-01 19:43 ` David Tolpin
2004-03-01 21:07 ` Derek Fawcus
2004-03-01 21:12 ` David Tolpin
2004-03-02 2:46 ` boyd, rounin
2004-03-02 6:02 ` David Tolpin
2004-03-02 12:31 ` Bruce Ellis
2004-03-02 18:46 ` boyd, rounin
2004-03-02 12:19 ` Dick Davies
2004-03-02 18:40 ` boyd, rounin
2004-03-04 3:52 ` Martin C.Atkins
2004-03-04 9:07 ` Bruce Ellis
2004-03-01 21:15 ` Charles Forsyth
2004-03-01 21:20 ` rog
2004-03-02 2:48 ` Joel Salomon
2004-03-03 3:58 ` Martin C.Atkins
2004-03-01 9:36 ` Geoff Collyer
2004-03-01 12:06 ` boyd
2004-03-01 14:55 ` David Presotto
2004-03-01 12:18 ` boyd
2004-03-01 13:29 ` Fco.J.Ballesteros
2004-03-01 13:33 ` lucio
2004-03-01 13:55 ` boyd
2004-03-02 4:13 ` Taj Khattra
2004-03-02 4:34 ` Roman Shaposhnick
2004-03-02 4:47 ` ron minnich
2004-03-02 5:53 ` Roman Shaposhnick
2004-03-02 5:58 ` ron minnich
2004-03-02 15:49 ` boyd, rounin
2004-03-02 7:00 ` rob pike, esq.
2004-03-02 20:58 ` Andrew Simmons
2004-03-02 21:23 ` boyd, rounin
2004-03-03 7:05 ` Anastasopoulos S
2004-03-03 5:11 ` Kenji Okamoto
2004-03-03 5:26 ` boyd, rounin
2004-03-03 9:49 ` Bruce Ellis
2004-03-03 12:41 ` boyd, rounin
2004-03-03 9:42 ` Bruce Ellis
2004-03-03 7:55 ` 9nut
2004-02-27 6:59 ` Donald Brownlee
2004-02-27 7:49 ` boyd, rounin
2004-02-27 10:11 ` [9fans] " Douglas A. Gwyn
2004-02-28 5:20 ` Martin C.Atkins
2004-02-28 9:44 ` Nigel Roles
2004-02-28 11:08 ` viro
2004-02-28 13:40 ` Nigel Roles
2004-02-28 13:36 ` boyd, rounin
2004-02-28 14:14 ` viro
2004-02-28 18:16 ` Nigel Roles [this message]
2004-02-28 18:53 ` viro
2004-02-28 19:44 ` Charles Forsyth
2004-02-28 20:13 ` Rob Pike
2004-03-01 11:50 ` viro
2004-03-01 11:49 ` dbailey27
2004-02-28 13:32 ` boyd, rounin
2004-03-01 10:35 ` Douglas A. Gwyn
2004-03-01 11:01 ` Geoff Collyer
2004-03-01 19:13 ` Joel Salomon
2004-03-01 10:35 ` Douglas A. Gwyn
2004-02-28 13:41 ` David Presotto
2004-03-02 21:59 Keith Nash
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='001d01c3fe27$09478e90$2bdcfea9@blue' \
--to=nigel@9fs.org \
--cc=9fans@cse.psu.edu \
/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).