From: Manfred Spraul <manfred@colorfullife.com>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Ben LaHaise <bcrl@redhat.com>, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] zero^H^H^H^Hsingle copy pipe
Date: Mon, 07 May 2001 23:48:08 +0200 [thread overview]
Message-ID: <3AF71818.F58139C6@colorfullife.com> (raw)
In-Reply-To: <E14wscv-00046J-00@the-village.bc.nu>
Alan Cox wrote:
>
> > The main problem is that map_user_kiobuf() locks pages into memory.
> > It's a bad idea for pipes. Either we must severely limit the maximum
>
> You only have to map them for the actual copy.
The current map_user_kiobuf() doesn't have an 'mm' parameter, I can only
use it from the context of the writer.
I could use map_user_kiobuf_mm(), but the kiobuf structure is far too
large, I really don't want a huge structure (> 8 kB?) for a simple 4 kB
single copy transfer.
Including a memset(,0,sizeof(*iobuf) in kiobuf_init().
I think reusing the ptrace interface (access_process_vm()) is the better
solution.
--
Manfred
next parent reply other threads:[~2001-05-07 21:48 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <E14wscv-00046J-00@the-village.bc.nu>
2001-05-07 21:48 ` Manfred Spraul [this message]
[not found] <mailman.989055541.17259.linux-kernel2news@redhat.com>
2001-05-07 16:15 ` [PATCH] zero^H^H^H^Hsingle copy pipe Ben LaHaise
2001-05-07 16:35 ` Manfred Spraul
2001-05-07 16:49 ` Ben LaHaise
2001-05-07 23:04 ` David S. Miller
2001-05-07 23:05 ` David S. Miller
2001-05-05 13:05 Manfred Spraul
[not found] ` <m2wv7vk2xi.fsf@boreas.yi.org.>
[not found] ` <3AF45FAB.595951F8@colorfullife.com>
[not found] ` <m2k83vjyrz.fsf@boreas.yi.org.>
[not found] ` <3AF473F8.F01EF82A@colorfullife.com>
2001-05-07 17:01 ` John Fremlin
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