Hi... On Wed, May 30, 2012 at 6:50 AM, Abu Rasheda <rcpilot2010@xxxxxxxxx> wrote: > So obviously, CPU is stalling when it is copying data and there are > more cache misses. My question is, is there a difference calling > copy_from_user from kernel proper compared to calling from LKM ? Theoritically, it should be the same. However, one thing that might interest you is that the fact that linux kernel module memory area is prepared through vmalloc(), thus there is a chance they are not physically contigous...whereas the main kernel image are using page_alloc() IIRC thus physically contigous. What I meant here is, there must be difference speed when you copy onto something contigous vs non contigous. IIRC at least it will waste some portion of L1/L2 cache. Just my 2 cents, maybe I am wrong somewhere... -- 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
