Date: Tue, 18 Dec 2001 16:05:37 -0800 (PST) From: John Baldwin <jhb@FreeBSD.org> To: alpha@FreeBSD.org Subject: Found bug with interrupts on current Message-ID: <XFMail.011218160537.jhb@FreeBSD.org>
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I have been having problems on the DS20 I have here with it getting interrupts stuck disabled under load when SMP is enabled, and I think I've found the problem. The various places in the platform code where we enable and disable an interrupt don't use any locks. At best, some of them use splhigh/splx (which doesn't do any good), so it seems there are several places where races could clobber interrupt masks on both UP and SMP systems. I've added a new spin lock to fix this but haven't tested it yet. :) (So it's currently in the smpng p4 tree until I can confirm that it works.) FWIW, x86 UP also was subject to some potential races as well I think. Also, there are a couple of minor notes: 1) The EBPC164 and PC164 interrupt enable/disable code is all in assembly, so I may need to add C wrappers around them that grab and release the lock as needed. 2) The dwlpx code in alpha/tlsb doesn't even have enable/disable hooks for interrupts at all, so it's likely very broken on current at the moment. I havent' fixed this yet because there was discussion a while back about dropping support for it, but fixing it wouldn't be that hard as the code to do it is already present. All that is needed are some wrapper functions to enable/disable and to take a vector and extract the intpin from it. -- John Baldwin <jhb@FreeBSD.org> <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve!" - http://www.FreeBSD.org/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-alpha" in the body of the message
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