On Thu 28-04-16 11:40:59, Mikulas Patocka wrote: [...] > There are many users that use one of these patterns: > > if (size <= some_threshold) > p = kmalloc(size); > else > p = vmalloc(size); > > or > > p = kmalloc(size); > if (!p) > p = vmalloc(size); > > > For example: alloc_fdmem, seq_buf_alloc, setxattr, getxattr, ipc_alloc, > pidlist_allocate, get_pages_array, alloc_bucket_locks, > frame_vector_create. If you grep the kernel for vmalloc, you'll find this > pattern over and over again. It is certainly good to address a common pattern by a helper if it makes to code easier to follo IMHO. > > In alloc_large_system_hash, there is > table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL); > - that is clearly wrong because __vmalloc doesn't respect GFP_ATOMIC I have seen this code some time already. I guess it was Al complaining about it but then I just forgot about it. I have no idea why GFP_ATOMIC was used there. This predates git times but it should be https://www.kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.10/2.6.10-mm1/broken-out/alloc_large_system_hash-numa-interleaving.patch The changelog is quite verbose but no mention about this ugliness. So I do agree that the above should be fixed and a common helper might be interesting but I am afraid we are getting off topic here. Thanks! -- Michal Hocko SUSE Labs -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
