Very interesting!! Both the link and the movntq instruction. I'll read and study.
Thanks Tobias!! 2012/12/8 Tobias Boege <[email protected]> > On Sat, 08 Dec 2012, Gustavo da Silva wrote: > > Hello Kernel Brothers!! How are you??? > > > > So, I would like test the performance of my notebook, developing one or > two > > utilities, and have a better > > mensurement about the speed. > > > > But it can help all of us. > > > > 1st: I would like mensure the speed making a counter (exacly bogomips? > may > > be). Loop+counter during 1 tickrate. > > 2nd: The most interesting: How many memory cells in ram can we > > access during 1tickrate? How could we develop this?! > > > > Both utils may run in long mode (64bits). Well, in real mode too; so, we > > can compare the speed in the two modes! > > > > Some one knows how to develop a very small program/routine about that?! > > > > For the 2nd situation, a simple idea wrote in codesnipet form (consider > the > > intention, not the sintax! there are bugs! I know. Intel syntax.) > > Obviously! ;-) > > > > > dw the_counter_cell 0 > > lea bx, the_counter_cell > > xor bx,bx > > label: > > inc [bx] # Could not be so simple like this, because the address can > > be cached. Right? > > loop label # breaked by an interruption. Just to express the intention. > > > > How could we create a small code for the 2nd situation, tring to force > the > > processor to not use the cache? > > As Drepper says[0], use the movntq instruction on x86_64 to bypass the > cache. > > Regards, > Tobi > > [0] http://www.akkadia.org/drepper/cpumemory.pdf p. 47ff. > > > _______________________________________________ > Kernelnewbies mailing list > [email protected] > http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies > -- Atenciosamente, Gustavo da Silva [email protected]
_______________________________________________ Kernelnewbies mailing list [email protected] http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
