On Sun, 2013-10-20 at 17:29 -0400, Neil Horman wrote: > On Fri, Oct 18, 2013 at 02:15:52PM -0700, Eric Dumazet wrote: > > On Fri, 2013-10-18 at 16:11 -0400, Neil Horman wrote: > > > > > #define BUFSIZ_ORDER 4 > > > #define BUFSIZ ((2 << BUFSIZ_ORDER) * (1024*1024*2)) > > > static int __init csum_init_module(void) > > > { > > > int i; > > > __wsum sum = 0; > > > struct timespec start, end; > > > u64 time; > > > struct page *page; > > > u32 offset = 0; > > > > > > page = alloc_pages((GFP_TRANSHUGE & ~__GFP_MOVABLE), BUFSIZ_ORDER); > > > > Not sure what you are doing here, but its not correct. > > > Why not? You asked for a test with 32 hugepages, so I allocated 32 hugepages.
Not really. We cannot allocate 64 Mbytes in a single alloc_pages() call on x86. (MAX_ORDER = 11) You noticed nothing because you did not write anything on the 64Mbytes area (and corrupt memory) or use CONFIG_DEBUG_PAGEALLOC=y. Your code read data out of bounds and was lucky, thats all... You in fact allocated a page of (4096<<4) bytes -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/