From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anthony Liguori Subject: Re: [PATCH] Cleanup rmb()/wmb() usage Date: Wed, 23 Feb 2005 01:57:41 -0600 Message-ID: <421C3775.30609@codemonkey.ws> References: <421BFACD.7090606@us.ibm.com> <274e9a0afab152618221454d6db8acff@cl.cam.ac.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit In-Reply-To: <274e9a0afab152618221454d6db8acff@cl.cam.ac.uk> Sender: xen-devel-admin@lists.sourceforge.net Errors-To: xen-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , List-Archive: To: Keir Fraser Cc: Anthony Liguori , xen-devel List-Id: xen-devel@lists.xenproject.org Keir Fraser wrote: > > On 23 Feb 2005, at 03:38, Anthony Liguori wrote: > > asm/system.h is a private kernel header so should not be directly > included from user space. Inlcuding it may not work for all versions > of Linux, or for other architectures. Actually, asm/system.h is designed for inclusion in userspace apps (and kernel space). Hence the __KERNEL__ guards around certain sections. It's used in a few notable userspace apps including glibc and MySQL. That said, Xen should not depend on Linux if it doesn't have to. > We should probably merge the barrier defs we have scattered in the > tools directory into one low-level architectural header that we > include everywhere, and extend for x86/64, ia64, and so on. Agreed. Any ideas on where it would live? I didn't see any likely place which is why I used asm/system. io/ring.h seemed the closest fit but that's not architecture specific. > Only Centaur clones that have been set up by the kernel to do write > combining. Xen does not ever enable write-combining on normal RAM and > so a barrier is never required. Ah, that makes sense. It still would be nice to have the barriers in a single location. Pick a place and I'll submit a patch. Regards, -- Anthony Liguori anthony@codemonkey.ws ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click