On Mon, 22 Mar 2010, Johannes Weiner wrote: > > entries while walking the page tables! Go incrementally use what > > is there. > > That only works if you merely read the tables. If the VMA gets broken > up in the middle of a huge page, you definitely have to map ptes again. Yes then follow the established system for remapping stuff. > And as already said, allowing it to happen always-succeeding and > atomically allows to switch users step by step. It results in a volatility in the page table entries that requires new synchronization procedures. It also increases the difficulty in establishing a reliable state of the pages / page tables for operations since there is potentially on-the-fly atomic conversion wizardry going on. > That sure sounds more incremental to me than being required to do > non-trivial adjustments to all the places at once! You do not need to do this all at once. Again the huge page subsystem has been around for years and we have established mechanisms to move/remap. There nothing hindering us from implementing huge page -> regular page conversion using the known methods or also implementing explicit huge page support in more portions of the kernel. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>