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To: Peter Wemm <peter@spinner.dialix.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 18:03:16 +0800."
             <199612151003.SAA14741@spinner.DIALix.COM> 
Date: Sun, 15 Dec 1996 11:17:14 +0100
Message-ID: <9319.850645034@critter.tfs.com>
From: Poul-Henning Kamp <phk@critter.tfs.com>
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In message <199612151003.SAA14741@spinner.DIALix.COM>, Peter Wemm writes:
>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();

Well more like:

	for (i=0;i<NCPU;i++)
		if (is_userland(i) && curproc[i]->p_vmspace->vm_refcnt > 1)
			send_tlb_invalidate(i);

--
Poul-Henning Kamp           | phk@FreeBSD.ORG       FreeBSD Core-team.
http://www.freebsd.org/~phk | phk@login.dknet.dk    Private mailbox.
whois: [PHK]                | phk@tfs.com           TRW Financial Systems, Inc.
Power and ignorance is a disgusting cocktail.