Hi... On Mon, Nov 26, 2012 at 1:51 PM, Vijay Chauhan <kernel.vi...@gmail.com> wrote: > Is it necessary that vmalloc always allocate virtually contiguous > memory and not physically contiguous?
to the best I know, yes vmalloc allocate virtually contigous. However, since they manage the pages by fiddling with the page tables, there is a chance that some of them are physically contigous IMHO > Except large size memory allocation why one needs to use vmalloc? Can > we say that use kmalloc and if it fails retry with kmalloc? nice question: AFAIK vmalloc() is made to tackle large size memory allocation, or in other word to side step memory fragmentation issue. IIRC too, that by using vmalloc, the vmalloc-ed area are guarded by guard pages on both start and end address. So it's like stack overflow guard pages. But don't count me on this info. Check it by yourself. -- regards, Mulyadi Santosa Freelance Linux trainer and consultant blog: the-hydra.blogspot.com training: mulyaditraining.blogspot.com _______________________________________________ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
