Hi Peter... On Sat, Feb 11, 2012 at 20:57, Peter Senna Tschudin <peter.senna@xxxxxxxxx> wrote: > Graeme, > > I found a problem on my code. I was calling kmalloc() only once for > both portions of code. The result is that the first loop that accessed > the memory was finding some penalty. Now I'm calling independent > kmalloc for each test. Sorry for jumping in the mid of discussion :) I read your code and I think kmalloc can be streamlined here. I recommend that kmalloc() allocate total memory needed to handle whole q->buf[] array. something like (CMIIW): q->buf=kmalloc(sizeof(struct vb_buffer)*q->num_buffers,GFP_KERNEL) then access q->buf[1], q->buf[2] etc. This way, AFAIK, you will likely get not only virtually continous pages, but also physical continous pages. And that will ease prefetching into L1/L2 cache. -- regards, Mulyadi Santosa Freelance Linux trainer and consultant blog: the-hydra.blogspot.com training: mulyaditraining.blogspot.com _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
