(2013/03/27 11:22), Minchan Kim wrote: > Swap subsystem does lazy swap slot free with expecting the page > would be swapped out again so we can't avoid unnecessary write. > > But the problem in in-memory swap is that it consumes memory space > until vm_swap_full(ie, used half of all of swap device) condition > meet. It could be bad if we use multiple swap device, small in-memory swap > and big storage swap or in-memory swap alone. > > This patch changes vm_swap_full logic slightly so it could free > swap slot early if the backed device is really fast. > For it, I used SWP_SOLIDSTATE but It might be controversial. > So let's add Ccing Shaohua and Hugh. > If it's a problem for SSD, I'd like to create new type SWP_INMEMORY > or something for z* family. > > Other problem is zram is block device so that it can set SWP_INMEMORY > or SWP_SOLIDSTATE easily(ie, actually, zram is already done) but > I have no idea to use it for frontswap. > > Any idea? > Another thinking....in what case, in what system configuration, vm_swap_full() should return false and delay swp_entry freeing ? Thanks, -Kame -- 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>