From: Andi Kleen <andi@firstfloor.org>
To: Andy Lutomirski <luto@MIT.EDU>
Cc: Andi Kleen <andi@firstfloor.org>, Ingo Molnar <mingo@elte.hu>,
linux-kernel@vger.kernel.org, libc-alpha@sourceware.org,
Andi Kleen <ak@linux.intel.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Andrew Morton <akpm@linux-foundation.org>,
Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH 4/5] Add a sysconf syscall
Date: Mon, 16 May 2011 18:08:10 +0200 [thread overview]
Message-ID: <20110516160810.GB25898@one.firstfloor.org> (raw)
In-Reply-To: <4DD14814.8080305@mit.edu>
> You could also add a vsyscall function and have that function pull the
> values from vvar data. It would be very fast (i.e. almost as fast as
> mmaping some data) and it would be more portable.
vvar is a global. The variable data in sysconf is per thread
(and not even per mm)
Even if you ignore the semantic problem of thread versus mm, you would
need a new writable page per process and update it any time
the rlimits and other information is updated.
On the other hand my solution is dead simple and already solves
the problem.
-Andi
next prev parent reply other threads:[~2011-05-16 16:08 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-13 23:24 Andi Kleen
2011-05-13 23:24 ` [PATCH 1/5] VFS: Make symlink nesting limit a define Andi Kleen
2011-05-13 23:24 ` [PATCH 2/5] Move max_threads variable declaration into include file Andi Kleen
2011-05-13 23:24 ` [PATCH 3/5] EXEC: Use define for stack to argument size limit Andi Kleen
2011-05-13 23:24 ` [PATCH 4/5] Add a sysconf syscall Andi Kleen
2011-05-14 6:57 ` Ingo Molnar
2011-05-14 16:34 ` Andi Kleen
2011-05-16 13:36 ` Ingo Molnar
2011-05-17 11:25 ` Ingo Molnar
2011-05-16 15:51 ` Andy Lutomirski
2011-05-16 16:08 ` Andi Kleen [this message]
2011-05-16 17:06 ` Andrew Lutomirski
[not found] ` <OFCC4C610A.F152D00D-ON86257892.005E11F4-86257892.005E22BA@us.ibm.com>
[not found] ` <4DD15E9B.2090809@linux.intel.com>
2011-05-17 10:59 ` Ingo Molnar
2011-05-16 15:42 ` Denys Vlasenko
2011-05-16 16:01 ` Andi Kleen
[not found] ` <OF30360F87.5C6D6DCF-ON86257892.005D7E68-86257892.005E0059@us.ibm.com>
2011-05-16 17:39 ` Andi Kleen
[not found] ` <OFD2EE69FB.301A458A-ON86257892.00631BE8-86257892.006A93AF@us.ibm.com>
2011-05-16 20:51 ` Andi Kleen
2011-05-17 12:33 ` Denys Vlasenko
2011-05-13 23:24 ` [PATCH 5/5] Hook up sysconf syscall for all architectures Andi Kleen
2011-05-14 1:21 ` David Miller
2011-05-14 2:51 ` Andi Kleen
2011-05-14 2:23 ` Mike Frysinger
2011-05-24 1:46 ` Mike Frysinger
2011-05-26 18:04 ` Mike Frysinger
2011-05-26 18:45 ` Andi Kleen
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