From: Andrew Vasquez <andrew.vasquez@qlogic.com>
To: jvrao <jvrao@linux.vnet.ibm.com>
Cc: LKML <linux-kernel@vger.kernel.org>,
rt-users <linux-rt-users@vger.kernel.org>,
Mike Anderson <andmike@linux.vnet.ibm.com>,
"Luis Claudio R. Goncalves" <lgoncalv@redhat.com>,
Linux Driver <Linux-Driver@qlogic.com>
Subject: Re: Interrupts are being dropped under heavy IO on -rt .
Date: Wed, 15 Apr 2009 12:48:02 -0700 [thread overview]
Message-ID: <20090415194802.GD1382@plap4-2.local> (raw)
In-Reply-To: <49DF71CF.7070509@linux.vnet.ibm.com>
On Fri, 10 Apr 2009, jvrao wrote:
> Qlogic driver uses MSI-EDGE interrupts by default.
>
> On -rt kernel under heavy IO load we observed that the driver missed
> interrupts occasionally.
>
> Missing interrupts caused spurious mailbox timeouts and path failovers.
>
> Suspecting MSI interrupts, we disabled MSI and forcing the driver to use
> APIC interrupts (Patch attached).
>
> With this change, our IO tests ran for extended period of time without
> any issues.
>
> It would be interesting to see if the MSI infrastructure itself has
> issues on realtime, or it is the combination of qla2xxx/MSI.
>
> Right now we don't have any setup to test out MSI with other adapters.
> Hence, wondering if anyone faced similar issues.
Could you perhaps provide some details on hardware used within your
testing -- HBA type, storage, etc? Also, can you share any logs of
the failures with extended-error-logging enabled
(ql2xextended_error_logging)?
Regards,
Andrew Vasquez
next prev parent reply other threads:[~2009-04-15 19:48 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-04-10 16:20 Interrupts are being dropped under heavy IO on -rt jvrao
2009-04-10 21:59 ` Thomas Gleixner
2009-04-15 19:48 ` Andrew Vasquez [this message]
2009-04-23 21:38 ` jvrao
2009-04-27 5:13 ` jvrao
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=20090415194802.GD1382@plap4-2.local \
--to=andrew.vasquez@qlogic.com \
--cc=Linux-Driver@qlogic.com \
--cc=andmike@linux.vnet.ibm.com \
--cc=jvrao@linux.vnet.ibm.com \
--cc=lgoncalv@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-rt-users@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.