[Top] [All Lists]

Re: MIPS_ATOMIC_SET in sys_sysmips()

To: "Maciej W. Rozycki" <>
Subject: Re: MIPS_ATOMIC_SET in sys_sysmips()
From: Harald Koerfgen <>
Date: Tue, 19 Dec 2000 18:03:01 +0100 (CET)
Cc:, Ralf Baechle <>, Jun Sun <>
In-reply-to: <>
Organization: none
Reply-to: Harald Koerfgen <>
On 19-Dec-00 Maciej W. Rozycki wrote:
> On Mon, 18 Dec 2000, Jun Sun wrote:
>> What do we offer to machines without ll/sc?
>  I asked Ralf for a clarification of the sysmips(MIPS_ATOMIC_SET, ...) 
> call before I write better code.  No response so far.  I'm now really
> cosidering implementing the Ultrix atomic_op() syscall -- at least it has
> a well-known defined behaviour. 

Another possibility would be to rely on the userland ll/sc emulation in the
kernel. The one in the linux-vr tree seems to be working well and can easily be
backported to Linux/MIPS.

Advantage: userland binary compatibility.
Disadvantage: possibility for a lot of context switches for userland atomic
Having a sysmips(MIPS_ATOMIC_SET, ...) or atomic_op() solution would probably a
lot faster.

Maybe we should implement both :)


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