On Thu, Feb 5, 2015 at 2:58 AM, Philipp Tölke <philipp.toelke@xxxxxxxx> wrote: > Hi everybody, > > Paul Gortmaker <paul.gortmaker <at> windriver.com> writes: >> -this patch is against 3.10-rt, but the code for all recent -rt >> that include the recent linux-stable rtmutex changes should have >> the same issue. [The 3.14-rt has a trivial path change where the >> kernel/rtmutex.c of v3.10 becomes kernel/locking/rtmutex.c but >> aside from that it applies to 3.14 too] >> >> -I'd got a report of this BUG_ON triggering on a v3.4-rt based >> kernel; that kernel was using my integration of the tglx rtmutex >> stable changes into 3.4-rt as described here: >> https://lkml.org/lkml/2014/9/23/944 >> but the related code in rostedt's 3.10.53-rt56 (in linux-stable-rt) >> and in tglx's 3.14.12-rt9 patch queue is AFAICT identical. So I >> have to conclude that anything using the stable rtmutex changes >> can inadvertently suffer the same BUG trigger. >> >> -this change gets us back to the pre-rtmutex stable commit behaviour, >> but I suspect that smarter people than me can advise on a way to >> achieve the same end result. So I'll wait before adding anything >> to the linux-stable-rt branches I'd put here at: >> https://git.kernel.org/cgit/linux/kernel/git/paulg/linux-stable-rt.git > > What is the status of this patch? I have a machine here I can get to crash in > about half an hour by doing a bidirectional iperf as proposed in > <http://thread.gmane.org/gmane.linux.rt.user/12681>. > > Ffor posterity: The command is "iperf -c 1.2.3.4 -i 10 -d -l 64k -t 50400" > which would normally do a 14 hour-iperf test against 1.2.3.4. > > My machine crashes with both 3.10.53-rt56 and 3.14.29-rt26. After > applying your patch to 3.14 the machine has not crashed in 24 hours. Yeah, FWIW, I've been using it on 3.4, 3.10 and 3.14 since my original post. > > Have "smarter people" had a chance to advise about this patch? Is there any > reason not to use it? 1) No, and 2) not AFAIK. I've added Steve to Cc: hopefully he can take a look and decide whether to merge it to stable-rt git repo. It seems like the results from you, myself and others do indicate it is a real issue though... and if this isn't the way to fix it then we will need some other fix. Paul. -- > > Regards, > Philipp Tölke -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
