On Tue, 2014-08-12 at 09:07 +0300, Kirill A. Shutemov wrote: > On Tue, Aug 12, 2014 at 08:00:54AM +0300, Oren Twaig wrote: > >Does memory allocated using vmalloc() will be mapped using huge > >pages either directly or later by THP ? > > No. It's neither aligned properly, nor physically contiguous. > > >If not, is there any fast way to change this behavior ? Maybe by > >changing the granularity/alignment of such allocations to allow such > >mapping ? > > What's the point to use vmalloc() in this case? Look at various large hashes we have in the system, all using vmalloc() : [ 0.006856] Dentry cache hash table entries: 16777216 (order: 15, 134217728 bytes) [ 0.033130] Inode-cache hash table entries: 8388608 (order: 14, 67108864 bytes) [ 1.197621] TCP established hash table entries: 524288 (order: 11, 8388608 bytes) I would imagine a performance difference if we were using hugepages. -- 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>