From: Arjan van de Ven <arjan@infradead.org>
To: Arnd Bergmann <arnd@arndb.de>
Cc: David Woodhouse <dwmw2@infradead.org>,
"Randy.Dunlap" <rddunlap@osdl.org>,
Matthew Wilcox <matthew@wil.cx>, Tonnerre <tonnerre@thundrix.ch>,
David Howells <dhowells@redhat.com>,
torvalds@osdl.org, hch@infradead.org, aoliva@redhat.com,
linux-kernel@vger.kernel.org, libc-hacker@sources.redhat.com
Subject: Re: [RFC] Splitting kernel headers and deprecating __KERNEL__
Date: Sun, 28 Nov 2004 13:19:45 +0100 [thread overview]
Message-ID: <1101644385.2638.11.camel@laptop.fenrus.org> (raw)
In-Reply-To: <200411281303.46609.arnd@arndb.de>
> > The problem with these (atomic.h
> >
> > that is a very non portable header and there are several good
> > alternatives (see the apr library for example). In fact. atomic.h is
> > *dangerous* in userspace, it is only atomic if CONFIG_SMP is set, so if
> > you compile your app on a machine without that set and then run it on an
> > smp machine, you are not atomic.
>
> Yes, it appears that most people who attempted to use this
> have already been bitten so hard that they stopped trying.
and for people who'd be tempted for new code it should at least warn if
not error even right now
> > > , byteorder.h,
> >
> > there are perfectly good alternatives in glibc
>
> Google found abuses of byteorder.h in kdeedu, dbootstrap and netatalk,
> I would expect to find many more if I kept looking.
it's still very much abuse, and quite nasty for dual endian platforms ;)
> > > , spinlock.h
> >
> > EHHHH????? Spinlocks in userland? You got to be kidding.
>
> I don't think it's that uncommon to use spinlocks in user
> space, IIRC samba (tdb) and some databases implement their
> own version of user spinlocks.
implementing your own is still evil, but glibc provides similar
constructs already. busy waiting in userspace is evil anyway (use futex
:) and.... just as with atomic.h, spinlock.h only gets compiled in for
CONFIG_SMP so the same caveats apply
> The kernel implementation
> is used at least in "Open Runtime Platform" and in "Chrony".
> Chrony even has an FAQ entry on how to circumvent the
> "#ifndef __KERNEL__" that was added in Red Hat Linux...
Chrony then needs to make their own (by copying and cleaning up for all
I care).
next prev parent reply other threads:[~2004-11-28 12:20 UTC|newest]
Thread overview: 185+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-11-25 15:13 [RFC] Splitting kernel headers and deprecating __KERNEL__ David Howells
2004-11-25 15:23 ` David Woodhouse
2004-11-25 16:54 ` Matthew Wilcox
2004-11-25 18:17 ` David Woodhouse
2004-11-27 3:24 ` Greg KH
2004-11-28 23:37 ` Paul Mackerras
2004-11-29 1:28 ` Linus Torvalds
2004-11-29 4:36 ` Jeff Garzik
2004-11-29 4:57 ` Al Viro
2004-11-29 5:27 ` Tim Hockin
2004-11-29 7:51 ` Arjan van de Ven
2004-12-05 0:49 ` Rob Landley
2004-12-05 2:26 ` Andries Brouwer
2004-12-05 13:19 ` David Greaves
2004-12-05 15:57 ` Andries Brouwer
2004-12-05 23:05 ` Rob Landley
2004-12-06 9:56 ` Andries Brouwer
2004-11-29 9:42 ` David Woodhouse
2004-11-30 8:08 ` Alex Riesen
2004-11-30 8:57 ` Alex Riesen
2004-12-01 11:46 ` Ralf Baechle
2004-12-02 1:21 ` H. Peter Anvin
2004-11-29 9:53 ` Paul Mackerras
2004-11-29 9:57 ` Arjan van de Ven
2004-11-29 10:01 ` David Woodhouse
2004-11-29 11:41 ` Mariusz Mazur
2004-11-29 17:09 ` Alexandre Oliva
2004-11-29 17:41 ` Linus Torvalds
2004-11-29 22:44 ` Al Viro
2004-12-01 11:36 ` Roman Zippel
[not found] ` <oract0thnj.fsf@livre.redhat.lsd.ic.unicamp.br>
2004-11-29 23:00 ` Linus Torvalds
2004-11-30 0:45 ` H. Peter Anvin
2004-11-30 5:31 ` Herbert Poetzl
2004-11-30 6:44 ` bert hubert
2004-11-30 21:22 ` Alexandre Oliva
2004-11-30 22:22 ` Linus Torvalds
2004-11-30 22:57 ` Alexandre Oliva
2004-11-30 23:12 ` Linus Torvalds
2004-12-01 19:41 ` Alexandre Oliva
2004-12-01 19:54 ` Matthew Wilcox
2004-12-02 3:58 ` Linus Torvalds
2004-12-02 4:28 ` Bernd Eckenfels
2004-12-02 5:11 ` Peter Williams
2004-12-02 11:30 ` Tomas Carnecky
2004-12-02 22:17 ` Peter Williams
2004-12-02 9:29 ` Pekka Enberg
2004-12-02 15:35 ` Linus Torvalds
2004-12-02 21:46 ` Pekka Enberg
2004-11-30 15:35 ` David Woodhouse
2004-11-30 15:58 ` Linus Torvalds
2004-11-30 16:28 ` David Woodhouse
2004-11-30 16:53 ` Linus Torvalds
2004-11-30 17:52 ` David Woodhouse
2004-11-30 18:21 ` Linus Torvalds
2004-11-30 20:28 ` Mariusz Mazur
2004-11-30 20:47 ` Linus Torvalds
2004-11-30 22:33 ` Sam Ravnborg
2004-11-30 22:44 ` Mariusz Mazur
2004-11-30 23:03 ` Al Viro
2004-11-30 23:08 ` Mariusz Mazur
2004-12-01 5:23 ` Sam Ravnborg
2004-12-01 10:52 ` Mariusz Mazur
2004-12-01 18:08 ` Sam Ravnborg
2004-11-30 23:13 ` Alexandre Oliva
2004-11-30 23:36 ` Chris Friesen
2004-12-01 5:50 ` H. Peter Anvin
2004-11-30 22:48 ` Matt Mackall
2004-11-30 22:51 ` Christoph Hellwig
2004-11-30 23:09 ` Chris Friesen
2004-11-30 23:35 ` Matt Mackall
2004-12-01 0:23 ` Miquel van Smoorenburg
2004-11-30 22:55 ` Linus Torvalds
2004-11-30 23:29 ` Matt Mackall
2004-12-03 1:03 ` Krzysztof Halasa
2004-11-30 23:51 ` David Woodhouse
2004-11-30 17:55 ` Al Viro
2004-11-30 16:33 ` David Howells
2004-11-30 16:57 ` Linus Torvalds
2004-11-30 15:33 ` David Howells
2004-11-30 15:51 ` Linus Torvalds
2004-11-30 20:47 ` Alexandre Oliva
2004-11-30 20:56 ` Linus Torvalds
2004-11-30 21:30 ` Alexandre Oliva
2004-11-30 21:39 ` Alexandre Oliva
2004-11-30 23:33 ` Matthew Wilcox
2004-11-30 22:25 ` Linus Torvalds
2004-11-30 22:34 ` David Woodhouse
2004-11-30 22:51 ` Linus Torvalds
2004-11-30 23:50 ` David Woodhouse
2004-12-01 0:10 ` Linus Torvalds
2004-12-01 0:18 ` Linus Torvalds
2004-12-01 8:10 ` Arjan van de Ven
2004-12-01 0:24 ` David Woodhouse
2004-12-01 0:37 ` Linus Torvalds
2004-12-01 0:47 ` David Woodhouse
2004-12-01 0:57 ` Linus Torvalds
2004-12-01 1:06 ` David Woodhouse
2004-12-01 1:23 ` Linus Torvalds
2004-12-01 6:48 ` BAIN
2004-12-01 2:02 ` cdrom.h (was Re: [RFC] Splitting kernel headers...) Matthew Wilcox
2004-11-30 22:52 ` [RFC] Splitting kernel headers and deprecating __KERNEL__ Mariusz Mazur
2004-11-30 23:05 ` Linus Torvalds
2004-11-30 23:05 ` Alexandre Oliva
2004-11-30 16:18 ` David Howells
2004-12-14 5:51 ` Werner Almesberger
2004-12-14 15:49 ` Linus Torvalds
2004-12-14 16:50 ` Werner Almesberger
2004-12-14 17:58 ` Linus Torvalds
2004-12-14 21:46 ` Werner Almesberger
2004-12-14 21:58 ` Linus Torvalds
2004-12-14 23:49 ` Krzysztof Halasa
2004-12-15 0:09 ` Werner Almesberger
2004-12-16 0:58 ` Krzysztof Halasa
2004-12-14 19:23 ` Horst von Brand
2004-12-14 19:45 ` Sam Ravnborg
2004-12-14 19:58 ` Linus Torvalds
2004-12-14 20:25 ` Andreas Schwab
2004-12-14 20:33 ` Linus Torvalds
2004-12-14 16:55 ` Andreas Schwab
2004-12-14 17:59 ` Linus Torvalds
2004-11-27 20:39 ` Sam Ravnborg
2004-11-25 18:20 ` Alexandre Oliva
2004-11-25 21:01 ` Matthew Wilcox
2004-11-25 22:35 ` David Woodhouse
2004-11-26 11:42 ` Alexandre Oliva
2004-11-27 0:13 ` Andreas Steinmetz
2004-11-27 0:26 ` David Woodhouse
2004-11-27 0:30 ` Andreas Steinmetz
2004-11-27 0:38 ` David Woodhouse
2004-11-26 11:47 ` Alexandre Oliva
2004-11-26 11:53 ` David Woodhouse
2004-11-27 16:12 ` Krzysztof Halasa
2004-11-26 11:58 ` David Howells
2004-11-26 12:00 ` David Woodhouse
2004-11-26 14:19 ` Matthew Wilcox
2004-11-26 14:33 ` David Woodhouse
2004-11-27 12:10 ` Alexander Stohr
2004-11-27 3:46 ` Adam Heath
2004-11-30 12:18 ` Horst von Brand
2004-11-29 16:34 ` Alexandre Oliva
2004-11-25 18:45 ` Matthew Wilcox
2004-11-26 11:52 ` David Howells
2004-11-26 23:56 ` Grzegorz Kulewski
2004-11-27 1:27 ` Tomas Carnecky
2004-11-27 1:41 ` Grzegorz Kulewski
2004-11-27 2:03 ` Tomas Carnecky
2004-11-27 3:07 ` Kyle Moffett
2004-11-27 4:29 ` Tonnerre
2004-11-27 3:51 ` Matthew Wilcox
2004-11-27 16:47 ` Randy.Dunlap
2004-11-27 17:16 ` David Woodhouse
2004-11-27 22:53 ` Arnd Bergmann
2004-11-27 23:12 ` David Woodhouse
2004-11-27 23:27 ` Randy.Dunlap
2004-11-27 23:32 ` David Woodhouse
2004-11-27 23:56 ` Arnd Bergmann
2004-11-28 7:13 ` Arjan van de Ven
2004-11-28 12:03 ` Arnd Bergmann
2004-11-28 12:19 ` Arjan van de Ven [this message]
2004-11-28 16:34 ` Kevin Puetz
2004-11-28 12:28 ` Wichert Akkerman
2004-11-28 12:44 ` Arjan van de Ven
2004-11-28 16:21 ` Jakub Jelinek
2004-11-28 7:20 ` Christoph Hellwig
2004-11-27 4:05 ` Chris Friesen
2004-11-27 4:30 ` Tomas Carnecky
2004-11-27 21:03 ` Sam Ravnborg
2004-11-27 21:11 ` Andreas Steinmetz
2004-11-27 21:19 ` Sam Ravnborg
2004-11-27 21:49 ` Andreas Steinmetz
2004-11-27 23:21 ` Arnd Bergmann
2004-11-28 13:24 ` Andreas Steinmetz
2004-11-28 13:40 ` Arnd Bergmann
2004-11-29 11:08 ` David Howells
2004-11-29 20:01 ` H. Peter Anvin
2004-11-30 0:34 ` Kyle Moffett
2004-11-30 0:51 ` H. Peter Anvin
2004-12-14 7:07 ` Werner Almesberger
2004-11-27 19:43 Dan Kegel
2004-11-27 21:06 ` Sam Ravnborg
[not found] <34Xo6-2P0-19@gated-at.bofh.it>
[not found] ` <35i9f-2vZ-25@gated-at.bofh.it>
[not found] ` <35iLS-2Uo-1@gated-at.bofh.it>
[not found] ` <35kb6-46Q-25@gated-at.bofh.it>
2004-11-28 0:55 ` ak
2004-11-28 13:32 ` Arnd Bergmann
2004-11-30 1:43 Jean Tourrilhes
2004-11-30 4:22 ` Linus Torvalds
2004-11-30 6:51 ` H. Peter Anvin
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