cvs commit: src/sys/alpha/alpha pmap.c src/sys/amd64/amd64pmap.c src/sys/i386/i386 pmap.c src/sys/vm vm_page.c

[Scott Long]

On Thu, 29 Jul 2004, Alan Cox wrote:
> alc         2004-07-29 18:56:31 UTC
>
>   FreeBSD src repository
>
>   Modified files:
>     sys/alpha/alpha      pmap.c
>     sys/amd64/amd64      pmap.c
>     sys/i386/i386        pmap.c
>     sys/vm               vm_page.c
>   Log:
>   Advance the state of pmap locking on alpha, amd64, and i386.
>
>    - Enable recursion on the page queues lock.  This allows calls to
>      vm_page_alloc(VM_ALLOC_NORMAL) and UMA's obj_alloc() with the page
>      queues lock held.  Such calls are made to allocate page table pages
>      and pv entries.

My understanding is that recursive mutexes are quite expensive.  Is
recursion a common occurrance now, and is there a good way to
profile/measure these paths?

Scott