On Thu 27-07-17 14:02:36, Liam R. Howlett wrote: > When a system runs out of memory it may be desirable to reclaim > unreserved hugepages. This situation arises when a correctly configured > system has a memory failure and takes corrective action of rebooting and > removing the memory from the memory pool results in a system failing to > boot. With this change, the out of memory handler is able to reclaim > any pages that are free and not reserved. I am sorry but I have to Nack this. You are breaking the basic contract of hugetlb user API. Administrator configures the pool to suit a workload. It is a deliberate and privileged action. We allow to overcommit that pool should there be a immediate need for more hugetlb pages and we do remove those when they are freed. If we don't then this should be fixed. Other than that hugetlb pages are not reclaimable by design and users do rely on that. Otherwise they could consider using THP instead. If somebody configures the initial pool too high it is a configuration bug. Just think about it, we do not want to reset lowmem reserves configured by admin just because we are hitting the oom killer and yes insanely large lowmem reserves might lead to early OOM as well. Nacked-by: Michal Hocko <mhocko@xxxxxxxx> -- 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>
