On Thu, May 17, 2012 at 6:50 PM, Dave Hansen <dave@xxxxxxxxxxxxxxxxxx> wrote: > On 05/17/2012 02:07 PM, Christoph Lameter wrote: >> >> On 2.6.32 and 3.4-rc6 mmap failure of a huge page causes a memory >> leak. The 32 byte kmalloc cache grows by 10 mio entries if running >> the following code: > > When called for anonymous (non-shared) mappings, hugetlb_reserve_pages() > does a resv_map_alloc(). It depends on code in hugetlbfs's > vm_ops->close() to release that allocation. > > However, in the mmap() failure path, we do a plain unmap_region() > without the remove_vma() which actually calls vm_ops->close(). > > As the code stands today, I think we can fix this by just making sure we > release the resv_map after hugetlb_acct_memory() fails. But, this seems > like a bit of a superficial fix and if we end up with another path or > two that can return -ESOMETHING, this might get reintroduced. The > assumption that vm_ops->close() will get called on all VMAs passed in to > hugetlbfs_file_mmap() seems like something that needs to get corrected. I agree. Now, resv_map_alloc() is called file open path and resv_map_free() is called vma close path. It seems asymmetry. It would be nice if resv_map_alloc can use vma->open ops. -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href