On Wed 06-04-16 17:12:43, Frank Mehnert wrote: > Hi Michal, > > On Wednesday 06 April 2016 17:02:06 Michal Hocko wrote: > > [CCing linux-mm mailing list] > > > > On Wed 06-04-16 13:28:37, Frank Mehnert wrote: > > > Hi, > > > > > > Linux 4.5 introduced additional checks to ensure that compound pages are > > > never marked as reserved. In our code we use PG_reserved to ensure that > > > the kernel does never swap out such pages, e.g. > > > > Are you putting your pages on the LRU list? If not how they could get > > swapped out? > > No, we do nothing like that. It was my understanding that at least with > older kernels it was possible that pages allocated with alloc_pages() > could be swapped out or otherwise manipulated, I might be wrong. I do not see anything like that. All the evictable pages should be on a LRU. > For > instance, it's also necessary that the physical address of the page > is known and that it does never change. I know, there might be problems > with automatic NUMA page migration but that's another story. Do you map your pages to the userspace? If yes then vma with VM_IO or VM_PFNMAP should keep any attempt away from those pages. -- Michal Hocko SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>