On Sat, Feb 18, 2012 at 07:49:13PM +0000, Mindaugas Rasiukevicius wrote: > > [...] > > I also implemented the idea of removing the mappings and freeing page > > in batch of 16 entries. Updated patch attached, I'm re-running the > > build.sh -jx release tests. This should also fix the problem in the native > > case as there's no #ifdef any more :) > > This is unnecessary (due to deferred invalidations), please keep it simple.
I guess it's the batch'ing of pmap_kremove that's unecessery. I'm not sure: some pmap_kremove() implementation do what looks like expensive calls (like PMAP_SYNC_ISTREAM_KERNEL on alpha, pmap_vac_me_harder() on arm, VAC flushing on m68k/motorola, and so on). Also, some platforms zero out pte using memset, and it's probably more efficient than zeroing one at a time > Note that the expensive TLB flushes is the reason why optimisations like > here exist: > > http://nxr.netbsd.org/xref/src/sys/uvm/uvm_map.c#2310 > > P.S. During rmind-uvmplock branch work, I checked all pmap_[k]remove() > cases, that they have pmap_update() and there are no race conditions, > so we should be fine. So should I move the pmap_update() back ? -- Manuel Bouyer <[email protected]> NetBSD: 26 ans d'experience feront toujours la difference --
