Re: CVS commit: src/sys/uvm

[Matt Thomas <matt%3am-software.com@localhost>]

On Sep 3, 2012, at 3:33 PM, Mindaugas Rasiukevicius wrote:

> "Matt Thomas" <matt%netbsd.org@localhost> 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.