From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <504EBA13.30909@ebus.com> Date: Mon, 10 Sep 2012 21:12:03 -0700 From: Doug Brunner MIME-Version: 1.0 References: <50483A49.5090100@ebus.com> <504C7797.8040201@xenomai.org> <504D3216.7030401@ebus.com> In-Reply-To: <504D3216.7030401@ebus.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Xenomai] Queue corruption from XDDP in Xenomai 2.6.1 List-Id: Discussions about the Xenomai project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Philippe Gerum Cc: xenomai@xenomai.org On 09/09/2012 05:19 PM, Doug Brunner wrote: > On 09/09/2012 04:03 AM, Philippe Gerum wrote: >> On 09/06/2012 07:53 AM, Doug Brunner wrote: >>> It looks like the bug I wrote about back in June still exists in >>> Xenomai >>> 2.6.1 (with Linux 3.2.21). I ran the same test case (an RT thread opens >>> an XDDP socket, then a Linux thread opens its end of the pipe, then the >>> RT thread stops, then with the Linux thread still holding its end of >>> the >>> pipe another RT thread tries to open an XDDP socket with the same minor >>> number). With Xenomai queue and I-pipe debugging enabled, I got a >>> report >>> of a corrupted queue. I've attached my config, test case, and serial >>> console log. >>> >>> So far I haven't found anything in the XDDP or underlying xnpipe_* code >>> that would suggest why this is happening. However something is >>> definitely going wrong, since xnpipe_minor_free should not be called >>> until my Linux task closes its end of the pipe, so the call by the >>> second RT thread to open the pipe should fail with -EBUSY. Any thoughts >>> on why this might be happening? >>> >> Yes, please have a look at the commit log there: >> http://git.xenomai.org/?p=xenomai-2.6.git;a=commit;h=283c5f6eae1d1d7c65073e2f30fd40abdcf2c1ca >> >> >> This patch should fix the issue raised by the test case you sent >> (actually, it does, it was very useful to spot the problem - thanks for >> this). > Thanks Philippe--I will patch this in and try it on my test hardware > tomorrow. (Unfortunately my KVM virtual machine will not boot any 3.2 > kernel with I-pipe AFAICT; around the time it remounts the root FS > read-write it begins waiting for something that never happens :( ) > > --Doug Brunner Works fine (passes regression test and appears to run my application OK), thanks again. I don't suppose anyone has a suggestion for what I might do to debug the hang during boot in KVM? :) --Doug Brunner