On Fri, Apr 22, 2016 at 11:49 PM, Andrew Morton <a...@linux-foundation.org> wrote: > On Fri, 15 Apr 2016 12:14:31 +0100 Chris Wilson <ch...@chris-wilson.co.uk> > wrote: > >> > > purge_fragmented_blocks() manages per-cpu lists, so that looks safe >> > > under its own rcu_read_lock. >> > > >> > > Yes, it looks feasible to remove the purge_lock if we can relax sync. >> > >> > what is still left is waiting on vmap_area_lock for !sync mode. >> > but probably is not that bad. >> >> Ok, that's bit beyond my comfort zone with a patch to change the free >> list handling. I'll chicken out for the time being, atm I am more >> concerned that i915.ko may call set_page_wb() frequently on individual >> pages. > > Nick Piggin's vmap rewrite. 20x (or more) faster. > https://lwn.net/Articles/285341/ > > 10 years ago, never finished.
But that's exactly what we are changing making 20.5x faster :) -- Roman
