From: Andrew Morton <akpm@osdl.org>
To: James Bottomley <James.Bottomley@SteelEye.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: [PATCH] Proposed update to the kernel kmap/kunmap API
Date: Sun, 6 Aug 2006 12:48:27 -0700 [thread overview]
Message-ID: <20060806124827.7f0e1993.akpm@osdl.org> (raw)
In-Reply-To: <1154876516.3683.201.camel@mulgrave.il.steeleye.com>
On Sun, 06 Aug 2006 10:01:55 -0500
James Bottomley <James.Bottomley@SteelEye.com> wrote:
> The simple part of the proposal is to give non-highmem architectures
> access to the kmap API for the purposes of overriding (this is what the
> attached patch does).
>
> The more controversial part of the proposal is that we should now
> require all architectures with coherence issues to manage data coherence
> via the kmap/kunmap API. Thus driver writers never have to write code
> like
kmap() is a nasty thing. It has theoretical deadlock problems (which used
to be real ones back in the 2.4 days) and the present implementation uses a
kernel-wide lock.
We've been gradually and sporadically working to make kmap() go away, so
please let's not do anything which encourages its use.
kmap_atomic() is much preferred. Can this initiative be recast around
kmap_atomic()?
next prev parent reply other threads:[~2006-08-06 19:48 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-08-06 15:01 James Bottomley
2006-08-06 19:48 ` Andrew Morton [this message]
2006-08-06 20:33 ` James Bottomley
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20060806124827.7f0e1993.akpm@osdl.org \
--to=akpm@osdl.org \
--cc=James.Bottomley@SteelEye.com \
--cc=linux-kernel@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®