From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 11 Aug 1999 21:40:49 -0700 From: Richard Henderson To: Paul.Mackerras@cs.anu.edu.au Cc: Jes.Sorensen@cern.ch, Geert.Uytterhoeven@cs.kuleuven.ac.be, linuxppc-dev@lists.linuxppc.org, linux-fbdev@vuser.vu.union.edu Subject: Re: [linux-fbdev] Re: readl() and friends and eieio on PPC Message-ID: <19990811214049.A14692@cygnus.com> References: <199908100100.LAA28784@tango.anu.edu.au> <199908110023.KAA23996@tango.anu.edu.au> <19990811003805.A11890@cygnus.com> <199908120017.KAA25043@tango.anu.edu.au> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <199908120017.KAA25043@tango.anu.edu.au>; from Paul Mackerras on Thu, Aug 12, 1999 at 10:17:34AM +1000 Sender: owner-linuxppc-dev@lists.linuxppc.org List-Id: On Thu, Aug 12, 1999 at 10:17:34AM +1000, Paul Mackerras wrote: > Sync and eieio are different in that for sync, the cpu actually stops > and waits for all memory accesses to complete, whereas for eieio the > cpu doesn't have to stop and wait for anything. Do alpha's mb and wmb > work the same way? Yes. (Except for EV4, in which wmb == mb, but we don't care about that.) > My position is that if you can provide the ordering at essentially > zero cost, then it is an advantage to have it since more drivers will > work that way. But it isn't zero cost. It's not high cost, but that's not the same thing. r~ [[ This message was sent via the linuxppc-dev mailing list. Replies are ]] [[ not forced back to the list, so be sure to Cc linuxppc-dev if your ]] [[ reply is of general interest. Please check http://lists.linuxppc.org/ ]] [[ and http://www.linuxppc.org/ for useful information before posting. ]]