linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Hugh Dickins <hugh@veritas.com>
To: Yingchao Zhou <yc_zhou@ncic.ac.cn>
Cc: linux-kernel <linux-kernel@vger.kernel.org>, akpm <akpm@osdl.org>,
	alan <alan@redhat.com>, zxc <zxc@ncic.ac.cn>
Subject: Re: Re: Re: [RFC] PAGE_RW Should be added to PAGE_COPY ?
Date: Fri, 15 Sep 2006 05:30:18 +0100 (BST)	[thread overview]
Message-ID: <Pine.LNX.4.64.0609150514190.7397@blonde.wat.veritas.com> (raw)
In-Reply-To: <20060915033842.C205FFB045@ncic.ac.cn>

On Fri, 15 Sep 2006, Yingchao Zhou wrote:
> >On Fri, 15 Sep 2006, Yingchao Zhou wrote:
> >> It's ok to mmap MAP_SHARED. But is it not a normal way to malloc() a space and
> >> then registered to NIC ?
> >
> >Not that I know of.  How would one register malloc()ed space to a NIC?
> >Sorry, I may well be misunderstanding you.
> The user-level NIC does this, eg. Myrinet...

Okay, thanks, I know nothing of that, and must defer to those who do.

But it sounds broken to me, in the way that you have described.

And the fix would not be to change the kernel's semantics for private
mappings, but for the app to use a shared mapping instead of a private.

Which would indeed be more work for the app than just using malloc,
since it needs some memory object (e.g. tmpfs file?) to map shared.

Hugh

  reply	other threads:[~2006-09-15  4:33 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-09-15  3:38 Re: Re: [RFC] PAGE_RW Should be added to PAGE_COPY ? Yingchao Zhou
2006-09-15  4:30 ` Hugh Dickins [this message]
2006-09-15 14:19   ` Hugh Dickins
2006-09-16  7:42     ` Nick Piggin
2006-09-23 18:51       ` Hugh Dickins
2006-09-25  2:53         ` Nick Piggin

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=Pine.LNX.4.64.0609150514190.7397@blonde.wat.veritas.com \
    --to=hugh@veritas.com \
    --cc=akpm@osdl.org \
    --cc=alan@redhat.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=yc_zhou@ncic.ac.cn \
    --cc=zxc@ncic.ac.cn \
    /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;
as well as URLs for NNTP newsgroup(s).