From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <3C4CECAF.6050309@embeddededge.com> Date: Mon, 21 Jan 2002 23:38:07 -0500 From: Dan Malek MIME-Version: 1.0 To: Ralph Blach Cc: linuxppc-embedded@lists.linuxppc.org, Mark Wisner , Alan Booker Subject: Re: consistent_alloc changes for 4xx/8xx References: Content-Type: text/plain; charset=us-ascii; format=flowed Sender: owner-linuxppc-embedded@lists.linuxppc.org List-Id: Ralph Blach wrote: > On the IBM book E part, __va()/__pa() will have to be obsoleted. The > address space is > 36 bits. Better now than later. These macros are not used on I/O space addresses, and would continue to work properly on the Book E parts when used as intended. In fact they are still used in all kernel ports, people just had the tendency to take shortcuts and abuse them. I was just pointing out one case of abuse that will now break. > Dan, you saw netperf which demonstrated the benefit. Netperf is not an application that does any real work, it is simply an IP stack performance tool. In the real world in real products, you have to be concerned with resources consumed by applications. When you pin TLB entries, you steal resources from applications and could cause a decline in the overall system performance. > .... These were the very > test you > suggested we run and they showed a >10% performance increase on a 405. I suggested netperf in response to your question about which network performance test to use, not as a tool to measure system performance. When you look at applications like MP3 players that are nearly 100% in user space, they are very sensitive to instruction and data cache footprint. Increasing the complexity of TLB miss handlers by adding more code or requiring the fetching of additional data, causes these applications to actually require more processing time. Thanks. -- Dan ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/