On Tue, May 27, 2014 at 12:19:16AM +0400, Konstantin Khlebnikov wrote: > On Mon, May 26, 2014 at 6:56 PM, Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote: > > Hi all, > > > > I mentioned at LSF/MM that I wanted to revive this, and at the time there were > > no disagreements. > > > > I finally got around to refreshing the patch(es) so here goes. > > > > These patches introduce VM_PINNED infrastructure, vma tracking of persistent > > 'pinned' page ranges. Pinned is anything that has a fixed phys address (as > > required for say IO DMA engines) and thus cannot use the weaker VM_LOCKED. One > > popular way to pin pages is through get_user_pages() but that not nessecarily > > the only way. > > Lol, this looks like resurrection of VM_RESERVED which I've removed > not so long time ago. Not sure what VM_RESERVED did, but there might be a similarity. > Maybe single-bit state isn't flexible enought? Not sure what you mean, the one bit is perfectly fine for what I want it to do. > This supposed to supports pinning only by one user and only in its own mm? Pretty much, that's adequate for all users I'm aware of and mirrors the mlock semantics. > This might be done as extension of existing memory-policy engine. > It allows to keep vm_area_struct slim in normal cases and change > behaviour when needed. > memory-policy might hold reference-counter of "pinners", track > ownership and so on. That all sounds like raping the mempolicy code and massive over engineering. -- 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>