linux-mips
[Top] [All Lists]

Re: LTP testing

To: Carsten Langgaard <carstenl@mips.com>
Subject: Re: LTP testing
From: Ralf Baechle <ralf@oss.sgi.com>
Date: Tue, 25 Jun 2002 16:39:41 +0200
Cc: "linux-mips@oss.sgi.com" <linux-mips@oss.sgi.com>
In-reply-to: <3D186E76.63B33B0E@mips.com>; from carstenl@mips.com on Tue, Jun 25, 2002 at 03:21:58PM +0200
References: <3D186E76.63B33B0E@mips.com>
Sender: owner-linux-mips@oss.sgi.com
User-agent: Mutt/1.2.5.1i
On Tue, Jun 25, 2002 at 03:21:58PM +0200, Carsten Langgaard wrote:

> The problem is that the code is called with $a0 = 0. So the 'sw v0,
> 0(a0)' after the syscall generates a segmentation fault.
> Why are the pipe syscall implemented this way, where we return the two
> descriptors in v0 and v1 ?
> Why doesn't the kernel do these stores (this way we can do an access
> check, like i386 does) ?

Because the interface we're using here is even lighter, even faster.  Note
that by the time when I decieded to use this interface this was potencially
a huge difference as verify_area() was searching the mm AVL trees, so this
interface was potenciall much faster by that time.

  Ralf

<Prev in Thread] Current Thread [Next in Thread>