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From: Miklos Szeredi <miklos@szeredi.hu>
To: andi@firstfloor.org
Cc: harvey.harrison@gmail.com, jdike@addtoit.com,
	akpm@linux-foundation.org, linux-kernel@vger.kernel.org,
	user-mode-linux-devel@lists.sourceforge.net
Subject: Re: uml and -regparm=3
Date: Wed, 09 Jan 2008 22:50:48 +0100	[thread overview]
Message-ID: <E1JCioy-0006os-6i@pomaz-ex.szeredi.hu> (raw)
In-Reply-To: <20080109213258.GC15612@one.firstfloor.org> (message from Andi Kleen on Wed, 9 Jan 2008 22:32:58 +0100)

> FASTCALL is useless and should not make a difference. It enables
> regparm on specific functions, but that should not make a difference
> if it works or not.

__down_write() in include/asm-x86/rwsem.h seems to assume, that the
semaphore pointer is passed in %eax down to rwsem_down_write_failed(),
so regparm does make a difference there.

There's also some intervening magic in arch/x86/lib/semaphore_32.S,
that I don't quite understand, but which doesn't seem to make a
difference.

Miklos

  reply	other threads:[~2008-01-09 21:51 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-01-09 21:01 Miklos Szeredi
2008-01-09 21:12 ` Andi Kleen
2008-01-09 21:20   ` Miklos Szeredi
2008-01-09 21:32     ` Andi Kleen
2008-01-09 21:50       ` Miklos Szeredi [this message]
2008-01-10  2:14         ` Jeff Dike
2008-01-10  2:37           ` Andi Kleen
2008-01-10  2:45             ` H. Peter Anvin
2008-01-09 21:33     ` Adrian Bunk
2008-01-09 22:01 ` linux-os (Dick Johnson)
2008-01-10  7:32 ` Ingo Molnar
2008-01-10  9:05   ` Miklos Szeredi
2008-01-10  9:35     ` Ingo Molnar

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