From: Jeremy Fitzhardinge <jeremy@goop.org>
To: Earl Chew <earl_chew@agilent.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: Using remap_pfn_range() to increase total_vm beyond RLIMIT_AS
Date: Mon, 19 Oct 2009 11:20:42 +0900 [thread overview]
Message-ID: <4ADBCCFA.1020507@goop.org> (raw)
In-Reply-To: <4AD7916A.2080200@agilent.com>
On 10/16/09 06:17, Earl Chew wrote:
> remap_pfn_range() is defined in mm/memory.c and as far as I
> can tell, does _not_ cause total_vm or reserved_vm to be updated.
>
> Is this right?
>
>
> RLIMIT_AS is only checked against total_vm in mm/mmap.c in the function
> may_expand_vm().
>
> I think this means that a device driver can map pages into
> a process and thus effectively increase address space of
> a process above and beyond the limit set by RLIMIT_AS.
I suspect this is justified because remap_pfn_range is generally
(always?) used to map device memory, and other memory which isn't
represented by struct pages, so it doesn't really count as real memory
usage.
J
next prev parent reply other threads:[~2009-10-19 2:40 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-10-15 21:17 Using remap_pfn_range() to increase total_vm beyond RLIMIT_AS Earl Chew
2009-10-19 2:20 ` Jeremy Fitzhardinge [this message]
2009-10-19 14:59 ` Earl Chew
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=4ADBCCFA.1020507@goop.org \
--to=jeremy@goop.org \
--cc=earl_chew@agilent.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.