From: Grant Grundler <iod00d@hp.com>
To: linux-ia64@vger.kernel.org
Subject: Re: [PATCH] SN2 user-MMIO CPU migration
Date: Tue, 24 Jan 2006 03:41:23 +0000 [thread overview]
Message-ID: <20060124034123.GS29214@esmail.cup.hp.com> (raw)
In-Reply-To: <20060118163305.Y42462@chenjesu.americas.sgi.com>
On Mon, Jan 23, 2006 at 06:33:39PM -0600, Brent Casavant wrote:
> However, when MMIO writes can be performed from user space (e.g. DRM)
> there are no such guarantees and mechanisms, as the process may
> context-switch at any time, and may migrate to a different CPU as part
> of the switch. For such programs/hardware to operate correctly, it is
> required that the MMIO writes from the old CPU be accepted by the IO
> hardware before subsequent writes from the new CPU can be issued.
Would an app first need to mmap an uncached address?
Or some other obvious "marker" that might warn the kernel?
I'm wondering if one could check some easily reachable state
(or flag) before calling platform_switch_from() and thus
mitigate Tony's concern.
grant
next prev parent reply other threads:[~2006-01-24 3:41 UTC|newest]
Thread overview: 73+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-01-20 0:06 [PATCH] SN2 user-MMIO CPU migration Brent Casavant
2006-01-20 2:18 ` Jesse Barnes
2006-01-20 6:47 ` Brent Casavant
2006-01-20 17:36 ` Jesse Barnes
2006-01-20 20:01 ` Brent Casavant
2006-01-20 13:26 ` Jack Steiner
2006-01-20 17:31 ` Jesse Barnes
2006-01-20 19:00 ` Jack Steiner
2006-01-20 8:36 ` Ingo Molnar
2006-01-20 16:14 ` Brent Casavant
2006-01-24 0:33 ` Brent Casavant
2006-01-24 0:48 ` Luck, Tony
2006-01-24 1:23 ` Brent Casavant
2006-01-24 1:42 ` Keith Owens
2006-01-24 3:41 ` Grant Grundler [this message]
2006-01-24 6:30 ` Brent Casavant
2006-01-24 6:41 ` Brent Casavant
2006-01-24 7:04 ` Grant Grundler
2006-01-24 9:02 ` Ingo Molnar
2006-01-24 9:14 ` Jes Sorensen
2006-01-24 12:10 ` Robin Holt
2006-01-24 16:40 ` Grant Grundler
2006-01-24 16:52 ` Brent Casavant
2006-01-24 16:57 ` Brent Casavant
2006-01-24 17:00 ` Robin Holt
2006-01-24 17:33 ` Luck, Tony
2006-01-24 18:42 ` Grant Grundler
2006-01-24 21:12 ` Brent Casavant
2006-01-24 21:41 ` Ingo Molnar
2006-01-24 21:43 ` Chen, Kenneth W
2006-01-24 21:51 ` Luck, Tony
2006-01-24 22:04 ` Brent Casavant
2006-01-24 22:07 ` Chen, Kenneth W
2006-01-24 22:12 ` Brent Casavant
2006-01-24 22:19 ` Chen, Kenneth W
2006-01-24 22:31 ` Chen, Kenneth W
2006-01-24 22:41 ` Brent Casavant
2006-01-24 23:25 ` Chen, Kenneth W
2006-01-24 23:28 ` Brent Casavant
2006-01-24 23:36 ` Chen, Kenneth W
2006-01-24 23:54 ` Brent Casavant
2006-01-25 0:10 ` Brent Casavant
2006-01-25 0:29 ` Chen, Kenneth W
2006-01-25 6:27 ` Keith Owens
2006-01-25 9:04 ` Chen, Kenneth W
2006-01-25 9:24 ` Chen, Kenneth W
2006-01-25 17:04 ` Brent Casavant
2006-01-25 17:45 ` Brent Casavant
2006-01-25 17:48 ` Brent Casavant
2006-01-25 19:01 ` Chen, Kenneth W
2006-01-25 19:15 ` Brent Casavant
2006-01-25 19:43 ` Jack Steiner
2006-01-25 22:49 ` Brent Casavant
2006-01-25 23:09 ` Brent Casavant
2006-01-25 23:49 ` Brent Casavant
2006-01-25 23:56 ` Chen, Kenneth W
2006-01-26 1:06 ` Luck, Tony
2006-01-26 1:31 ` Prarit Bhargava
2006-01-26 2:43 ` Keith Owens
2006-01-26 4:40 ` Brent Casavant
2006-01-26 16:29 ` Brent Casavant
2006-01-26 16:41 ` Prarit Bhargava
2006-01-26 19:29 ` Brent Casavant
2006-01-26 19:54 ` Luck, Tony
2006-01-26 20:28 ` Brent Casavant
2006-01-26 21:05 ` Luck, Tony
2006-01-26 21:34 ` Prarit Bhargava
2006-01-26 22:11 ` Luck, Tony
2006-01-26 23:08 ` Luck, Tony
2006-01-26 23:21 ` Prarit Bhargava
2006-01-26 23:44 ` Prarit Bhargava
2006-01-27 0:07 ` Chen, Kenneth W
2006-01-27 14:01 ` Prarit Bhargava
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=20060124034123.GS29214@esmail.cup.hp.com \
--to=iod00d@hp.com \
--cc=linux-ia64@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