If I remove the changes I'm not available to reach the previous result, and to perform the test I use an external traffic generator ( Smartbit) and this has an hight precision. So the problem in some way should be tied to cache but I don't know what I can try.I blocked some critical function (in term of cpu cycles) in istruction cache but I didn't obtained a good result Let me know if you have some idea
Thanks Aldo On 11/15/06, Dan Malek <[EMAIL PROTECTED]> wrote: > > On Nov 15, 2006, at 11:21 AM, Jeff Mock wrote: > > > I'm no big help, but the problem might be TLB related instead of cache > > related. The performance of embedded PPCs with small TLBs requiring > > software assist for TLB misses can be performance sensitive to TLB > > misses. > > The 82xx is fully cache coherent and has BATs for > mapping the kernel space. This is not a PPC with > a small TLB, but rather one of the most efficient. > The TLBs are not an issue, and I doubt the caches > are as well. > > I don't know what kind of test is used to measure this > performance, but the first thing you must always scrutinize > are your testing methods and procedures. Just using > a user application to measure network performance > enables a large number of variables that must be > properly understood and controlled. Some other > thread could have switched in and stolen CPU cycles, > you could have some sampling rate and time > measurement hysteresis due to buffering, > you need to find and control such things. > > Can you "undo" the changes and get the old > results? That's the first thing I would verify, > and then verify the results are repeatable. > If that's the case, I'd carefully try to understand > what this "unrelated" change really affects > in terms of using CPU cycles. > > Thanks. > > -- Dan > > _______________________________________________ Linuxppc-embedded mailing list [email protected] https://ozlabs.org/mailman/listinfo/linuxppc-embedded
