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From: Linus Torvalds <torvalds@linux-foundation.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Nick Piggin <npiggin@suse.de>,
	Andrew Morton <akpm@linux-foundation.org>,
	shaggy@austin.ibm.com, axboe@kernel.dk, linux-mm@kvack.org,
	linux-arch@vger.kernel.org, Clark Williams <williams@redhat.com>,
	Ingo Molnar <mingo@elte.hu>,
	Jeremy Fitzhardinge <jeremy@goop.org>
Subject: Re: [patch 2/2]: introduce fast_gup
Date: Thu, 17 Apr 2008 09:18:52 -0700 (PDT)	[thread overview]
Message-ID: <alpine.LFD.1.00.0804170916470.2879@woody.linux-foundation.org> (raw)
In-Reply-To: <1208448768.7115.30.camel@twins>


On Thu, 17 Apr 2008, Peter Zijlstra wrote:
> 
> Jeremy, did I get the paravirt stuff right?

I don't think this is worth it to virtualize.

We access the page tables directly in any number of places, having a 
"get_pte()" indirection here is not going to help anything.

Just make it an x86-only inline function. In fact, you can keep it inside 
arch/x86/mm/gup.c, because nobody else is likely to ever even need it, 
since normal accesses are all supposed to be done under the page table 
spinlock, so they do not have this issue at all.

The indirection and virtualization thing is just going to complicate 
matters for no good reason.

		Linus

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  reply	other threads:[~2008-04-17 16:18 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-03-28  2:54 [patch 0/2]: lockless get_user_pages patchset Nick Piggin
2008-03-28  2:55 ` [patch 1/2]: x86: implement pte_special Nick Piggin
2008-03-28  3:23   ` David Miller, Nick Piggin
2008-03-28  3:31     ` Nick Piggin
2008-03-28  3:44       ` David Miller, Nick Piggin
2008-03-28  4:04         ` Nick Piggin
2008-03-28  4:09           ` David Miller, Nick Piggin
2008-03-28  4:15             ` Nick Piggin
2008-03-28  4:16               ` David Miller, Nick Piggin
2008-03-28  4:19                 ` Nick Piggin
2008-03-28  4:17               ` Nick Piggin
2008-03-28  3:00 ` [patch 2/2]: introduce fast_gup Nick Piggin
2008-03-28 10:01   ` Jens Axboe
2008-04-17 15:03   ` Peter Zijlstra
2008-04-17 15:25     ` Linus Torvalds
2008-04-17 16:12       ` Peter Zijlstra
2008-04-17 16:18         ` Linus Torvalds [this message]
2008-04-17 16:35           ` Peter Zijlstra
2008-04-17 16:40             ` Linus Torvalds
2008-04-17 17:23               ` Peter Zijlstra
2008-04-17 18:28                 ` Linus Torvalds
2008-04-22  3:14                   ` Nick Piggin
2008-04-18  6:31                 ` Geert Uytterhoeven
2008-04-18 14:40                   ` Linus Torvalds
2008-04-18  9:58         ` Jeremy Fitzhardinge
2008-04-21 12:00       ` Avi Kivity
2008-04-21 12:30         ` Peter Zijlstra
2008-04-21 13:26           ` Avi Kivity
2008-04-21 14:35             ` Peter Zijlstra
2008-04-22  3:23               ` Nick Piggin
2008-04-22  7:19                 ` Avi Kivity
2008-04-22  8:07                 ` Ingo Molnar
2008-04-22  9:42   ` Peter Zijlstra
2008-04-22  9:46     ` Nick Piggin
2008-05-14 18:33       ` Dave Kleikamp
2008-05-15  1:13         ` Nick Piggin

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