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To: Poul-Henning Kamp <phk@critter.tfs.com>
cc: dyson@freebsd.org, smp@freebsd.org, haertel@ichips.intel.com
Subject: Re: some questions concerning TLB shootdowns in FreeBSD 
In-reply-to: Your message of "Sun, 15 Dec 1996 10:13:27 +0100."
             <9092.850641207@critter.tfs.com> 
Date: Sun, 15 Dec 1996 18:03:16 +0800
From: Peter Wemm <peter@spinner.dialix.com>
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Poul-Henning Kamp wrote:
> In message <199612150121.JAA12763@spinner.DIALix.COM>, Peter Wemm writes:
> 
> >However, the shared address space code that I was working on in
> >-current (for kernel assisted threading in the smp kernel) means
> >that a single vmspace/pmap/etc can be shared among multiple processes
> >and this changes the above picture since two cpu's can be using
> >the user mode parts of the same page tables at once, one in executing
> >in user mode, one in the kernel.
> 
> But we could still have a per-cpu flags:
> 	"I'm not in a shared address-space"
> 
> Ie, this would only be set if the CPU was in userland in a non-threaded
> process.

eg, something like: 
if (is_userland && curproc->p_vmspace->vm_refcnt > 1)
  send_tlb_invalidate();

Cheers,
-Peter