From: Ashok Raj <ashok.raj@intel.com>
To: Michael Raymond <mraymond@sgi.com>
Cc: "Luck, Tony" <tony.luck@intel.com>,
linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] User Level Interrupts
Date: Wed, 23 Mar 2005 22:57:39 +0000 [thread overview]
Message-ID: <20050323145738.A29828@unix-os.sc.intel.com> (raw)
In-Reply-To: <20050323103832.A108873@goliath.americas.sgi.com>; from mraymond@sgi.com on Wed, Mar 23, 2005 at 08:38:33AM -0800
Hi Michael
have you thought about how this infrastructure would play well with
existing CPU hotplug code for ia64?
Once you return to user mode via the iret, is it possible that user mode
thread could get switched due to a pending cpu quiese attempt to remove
a cpu? (Current cpu removal code would bring the entire system to knees
by scheduling a high priority thread and looping with intr disabled, until the
target cpu is removed)
the cpu removal code would also attempt to migrate user process to another cpu,
retarget interrupts to another existing cpu etc. I havent tested the hotplug
code on sgi boxes so far. (only tested on some hp boxes by Alex Williamson
and on tiger4 boxes so far)
Cheers,
ashok
On Wed, Mar 23, 2005 at 08:38:33AM -0800, Michael Raymond wrote:
>
> Allow fast (1+us) user notification of device interrupts. This
> allows
> more powerful user I/O applications to be written. The process of
> porting
> to other architectures is straight forward and fully documented. More
> information can be found at [1]http://oss.sgi.com/projects/uli/.
>
>
next prev parent reply other threads:[~2005-03-23 22:57 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-03-23 16:38 [PATCH] User Level Interrupts Michael Raymond
2005-03-23 22:57 ` Ashok Raj [this message]
2005-03-23 23:59 ` Michael Raymond
2005-03-24 14:50 ` Michael Raymond
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=20050323145738.A29828@unix-os.sc.intel.com \
--to=ashok.raj@intel.com \
--cc=linux-ia64@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mraymond@sgi.com \
--cc=tony.luck@intel.com \
/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