On Sep 3, 2012, at 3:33 PM, Mindaugas Rasiukevicius wrote: > "Matt Thomas" <m...@netbsd.org> wrote: >> Module Name: src >> Committed By: matt >> Date: Mon Sep 3 19:53:43 UTC 2012 >> >> Modified Files: >> src/sys/uvm: uvm_km.c uvm_map.c >> >> Log Message: >> Switch to a spin lock (uvm_kentry_lock) which, fortunately, was sitting >> there unused. > > - pmap_growkernel() may use adaptive locks, which cannot be acquired with > the spin lock held; so the change breaks at least x86 and alpha. > > - Why in the caller? I think it would be better do leave it for the pmaps, > e.g. they may re-use the locks which already provide the necessary > protection and which need to be taken anyway (like in x86 pmap).
uvm_maxkaddr need a lock for its updating growkernel can be called uvm_km_mem_alloc which might be called at interrupt level.
