From: Andrew Donnellan <andrew.donnellan@au1•ibm.com>
To: Michael Neuling <mikey@neuling•org>, mpe@ellerman•id.au
Cc: Joerg-Stephan Vogt <JSVOGT@de•ibm.com>,
Frederic Barrat <frederic.barrat@fr•ibm.com>,
Vaibhav Jain <vaibhav@linux•vnet.ibm.com>,
Wolfgang Bolz1 <Wolfgang.Bolz@de•ibm.com>,
imunsie@au1•ibm.com, Frank Haverkamp <HAVERKAM@de•ibm.com>,
linuxppc-dev@lists•ozlabs.org
Subject: Re: [PATCH 1/2] cxl: Keep IRQ mappings on context teardown
Date: Fri, 22 Apr 2016 15:14:14 +1000 [thread overview]
Message-ID: <5719B326.7030500@au1.ibm.com> (raw)
In-Reply-To: <1461301069-12331-1-git-send-email-mikey@neuling.org>
On 22/04/16 14:57, Michael Neuling wrote:
> Keep IRQ mappings on context teardown. This won't leak IRQs as if we
> allocate the mapping again, the generic code will give the same
> mapping used last time.
>
> Doing this works around a race in the generic code. Masking the
> interrupt introduces a race which can crash the kernel or result in
> IRQ that is never EOIed. The lost of EOI results in all subsequent
> mappings to the same HW IRQ never receiving an interrupt.
>
> We've seen this race with cxl test cases which are doing heavy context
> startup and teardown at the same time as heavy interrupt load.
>
> A fix to the generic code is being investigated also.
>
> Signed-off-by: Michael Neuling <mikey@neuling•org>
> cc: stable@vger•kernel.org # 3.8
Tested on top of 4.6-rc3 using the genwqe-echo test utility[0].
Tested-by: Andrew Donnellan <andrew.donnellan@au1•ibm.com>
[0]
https://github.com/ibm-genwqe/genwqe-user/blob/master/tools/genwqe_echo.c
--
Andrew Donnellan OzLabs, ADL Canberra
andrew.donnellan@au1•ibm.com IBM Australia Limited
next prev parent reply other threads:[~2016-04-22 5:15 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-22 4:57 [PATCH 1/2] cxl: Keep IRQ mappings on context teardown Michael Neuling
2016-04-22 4:57 ` [PATCH 2/2] cxl: Poll for outstanding IRQs when detaching a context Michael Neuling
2016-04-22 5:14 ` Andrew Donnellan
2016-04-22 5:18 ` Ian Munsie
2016-04-22 6:05 ` Vaibhav Jain
2016-04-28 1:52 ` [2/2] " Michael Ellerman
2016-04-22 5:14 ` Andrew Donnellan [this message]
2016-04-22 5:18 ` [PATCH 1/2] cxl: Keep IRQ mappings on context teardown Ian Munsie
2016-04-22 6:03 ` Vaibhav Jain
2016-04-28 1:52 ` [1/2] " Michael Ellerman
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=5719B326.7030500@au1.ibm.com \
--to=andrew.donnellan@au1$(echo .)ibm.com \
--cc=HAVERKAM@de$(echo .)ibm.com \
--cc=JSVOGT@de$(echo .)ibm.com \
--cc=Wolfgang.Bolz@de$(echo .)ibm.com \
--cc=frederic.barrat@fr$(echo .)ibm.com \
--cc=imunsie@au1$(echo .)ibm.com \
--cc=linuxppc-dev@lists$(echo .)ozlabs.org \
--cc=mikey@neuling$(echo .)org \
--cc=mpe@ellerman$(echo .)id.au \
--cc=vaibhav@linux$(echo .)vnet.ibm.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
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