Kyunghwan Kim writes:
 > On Wed, Dec 18, 2002 at 04:53:00AM +0900, Kyunghwan Kim wrote:
 > > On Tue, Dec 17, 2002 at 02:31:31PM -0500, Andrew Gallatin wrote:
 > > >  > mbuf and bpf routines are all mp-safe, so it seems that
 > > >  > it is safe to make network device drivers out of Giant lock.
 > > >  > Or is there any unresolved related issues?
 > > > 
 > > > Yes, the mbuf allocator must occasionally call kmem_malloc(), which
 > > > requires Giant.    This means no net driver can be made INTR_MPSAFE,
 > > > or it will eventually panic when kmem_malloc is called. 
 > > 
 > > I found and read the thread that you and Alan had discussed about this
 > > problem just before. Then what about making updated version of mb_pop_cont()
 > > that accepts occasionally acquiring Giant?
 > Oh, sorry. Conclusion of the thread was preallocation.
 > But it doesn't seem that preallocation is the correct way.

Well, the "right" way is bringing kmem_malloc() out from under Giant.
Preallocation would just be an interim measure until kmem_malloc() was

The VM maintainers were only recently made aware of this issue. I have
no idea what the scope of the changes to make kmem_malloc() mpsafe
would be, so I have no idea when kmem_malloc() will become mpsafe.


To Unsubscribe: send mail to [EMAIL PROTECTED]
with "unsubscribe freebsd-current" in the body of the message

Reply via email to