From: willy@linux.intel.com (Matthew Wilcox)
Subject: IRQ allocation in nvme driver
Date: Wed, 17 Oct 2012 18:55:18 -0400 [thread overview]
Message-ID: <20121017225518.GK4244@linux.intel.com> (raw)
In-Reply-To: <E821E2F372F08945977BD15EAE588D610846763F@SACMBXIP02.sdcorp.global.sandisk.com>
On Wed, Oct 17, 2012@10:40:34PM +0000, Chayan Biswas wrote:
> Yes, that is a better approach.
>
> However, in the current Linux driver, the NVME queue pointer is passed in the IRQ handler and hence it will require lot more code to choose the correct NVME queue pointer for MSIX 0 handler. Hence I chose the easier approach of allocating an additional MSIX without changing a lot of tested code.
Huh? The Linux NVMe driver requests vector 0 twice; once for the
admin queue and once for the first I/O queue. The interrupt handler
is called twice on every interrupt; once with the admin queue as the
pointer and once with the I/O queue as the pointer. This uses the
existing functionality in the Linux IRQ system rather than duplicating
it in the driver. I bet you can't measure the difference in performance
between I/O on queue 1 and I/O on queue 2.
next prev parent reply other threads:[~2012-10-17 22:55 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-17 21:38 IRQ allocation in nvme driver Chayan Biswas
2012-10-17 22:11 ` Luse, Paul E
2012-10-17 22:40 ` Chayan Biswas
2012-10-17 22:55 ` Matthew Wilcox [this message]
2012-10-18 21:21 ` Chayan Biswas
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=20121017225518.GK4244@linux.intel.com \
--to=willy@linux.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 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.