From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from oss.sgi.com (localhost [127.0.0.1]) by oss.sgi.com (8.12.3/8.12.3) with ESMTP id g4TLRinC031150 for ; Wed, 29 May 2002 14:27:44 -0700 Received: (from majordomo@localhost) by oss.sgi.com (8.12.3/8.12.3/Submit) id g4TLRi2Q031149 for linux-mips-outgoing; Wed, 29 May 2002 14:27:44 -0700 X-Authentication-Warning: oss.sgi.com: majordomo set sender to owner-linux-mips@oss.sgi.com using -f Received: from dea.linux-mips.net (localhost [127.0.0.1]) by oss.sgi.com (8.12.3/8.12.3) with ESMTP id g4TLRfnC031146 for ; Wed, 29 May 2002 14:27:41 -0700 Received: (from ralf@localhost) by dea.linux-mips.net (8.11.6/8.11.1) id g4TLStu01350; Wed, 29 May 2002 14:28:55 -0700 Date: Wed, 29 May 2002 14:28:55 -0700 From: Ralf Baechle To: "Kevin D. Kissell" Cc: Justin Carlson , linux-mips@oss.sgi.com Subject: Re: __flush_cache_all() miscellany Message-ID: <20020529142855.C888@dea.linux-mips.net> References: <1022691053.7644.16.camel@ldt-sj3-022.sj.broadcom.com> <1022700389.7644.155.camel@ldt-sj3-022.sj.broadcom.com> <01cb01c20754$4c14e400$10eca8c0@grendel> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5.1i In-Reply-To: <01cb01c20754$4c14e400$10eca8c0@grendel>; from kevink@mips.com on Wed, May 29, 2002 at 11:03:20PM +0200 X-Accept-Language: de,en,fr Sender: owner-linux-mips@oss.sgi.com Precedence: bulk On Wed, May 29, 2002 at 11:03:20PM +0200, Kevin D. Kissell wrote: > While trampolines, breakpointing and JITing are the main > uses of user-mode cache manipulation (drivers are a whole > 'nother story), we really should have distinct capabilities for > I-stream modification and for explicit synchronizations of > the data storage hierarchy, for non-coherent multiprocessors > and user-manipulated DMA buffers. As to whether > those capabilities should be distinguished by system > call (sysmips vs. cacheflush) or by parameter to the > same system call, I don't have enough data to form > an opinion at this point. It should clearly be cacheflush(2); sysmips(2) is too coarse, too ugly interface. Another thing we'll still have to implement is the cachectl(2) syscall; for certain systems and applications fine control of the caching mode use for a memory mapping may result in major performance improvments. Ralf