From: Andi Kleen <andi@firstfloor.org>
To: Vitaly Mayatskikh <v.mayatskih@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Andi Kleen <andi@firstfloor.org>,
linux-kernel@vger.kernel.org,
Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH 1/2] Introduce copy_user_handle_tail routine
Date: Mon, 7 Jul 2008 18:43:03 +0200 [thread overview]
Message-ID: <20080707164303.GD20428@one.firstfloor.org> (raw)
In-Reply-To: <m3zlotx587.fsf@gravicappa.englab.brq.redhat.com>
On Mon, Jul 07, 2008 at 02:12:56PM +0200, Vitaly Mayatskikh wrote:
> Vitaly Mayatskikh <v.mayatskih@gmail.com> writes:
>
> >> one), by limiting the byte-for-byte one to be within a page, but that
> >> would be a "future enhancement" thing.
> >
> > Btw, how much does it cost to CPU to do a fault? Can it be compared with
> > average time of find_vma()?
>
> Remark: this is for preventing fault in memset, not byte-to-byte copy.
memset never faults.
The current code doesn't handle it and it never happened.
-Andi
next prev parent reply other threads:[~2008-07-07 16:30 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-06-27 21:52 [PATCH 3/3] Fix copy_user on x86_64 Vitaly Mayatskikh
2008-06-28 18:26 ` Linus Torvalds
2008-06-30 15:12 ` Vitaly Mayatskikh
2008-06-30 15:55 ` Linus Torvalds
2008-06-30 16:16 ` Andi Kleen
2008-06-30 18:22 ` Kari Hurtta
2008-07-02 13:48 ` [PATCH 1/2] Introduce copy_user_handle_tail routine Vitaly Mayatskikh
2008-07-02 14:06 ` Andi Kleen
2008-07-02 14:31 ` Vitaly Mayatskikh
2008-07-02 15:06 ` Andi Kleen
2008-07-02 15:32 ` Vitaly Mayatskikh
2008-07-02 15:40 ` Andi Kleen
2008-07-02 15:58 ` Vitaly Mayatskikh
2008-07-02 18:54 ` Andi Kleen
2008-07-03 2:35 ` Linus Torvalds
2008-07-07 12:09 ` Vitaly Mayatskikh
2008-07-07 12:12 ` Vitaly Mayatskikh
2008-07-07 16:43 ` Andi Kleen [this message]
2008-07-07 16:21 ` Linus Torvalds
2008-07-07 17:05 ` Vitaly Mayatskikh
2008-07-09 13:03 ` Ingo Molnar
2008-07-09 13:16 ` Vitaly Mayatskikh
2008-07-09 13:52 ` Ingo Molnar
2008-07-02 13:53 ` [PATCH 2/2] Fix copy_user on x86 Vitaly Mayatskikh
2008-07-02 14:08 ` Andi Kleen
2008-07-02 14:36 ` Vitaly Mayatskikh
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