Article View: comp.os.mach
Article #922Re: interrupt and simple_locks
From: Rong Chen
Date: Thu, 04 Apr 1991 03:55
Date: Thu, 04 Apr 1991 03:55
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1363 bytes
dswartz@bigbootay.sw.stratus.com (Dan Swartzendruber) writes: >Interrupts must be masked first, since otherwise you have a race condition >where the lock is acquired on call-side and an interrupt comes in before >the spl call. If the interrupt handler tries to acquire the same lock, >you're stuck, since the only code which can release the lock is the same >thread which is now servicing the interrupt. Why do we want the interrupt handlers to acquire locks? I thought the interrupt handlers should always be executed from begin to end without any complications. Usually the handlers will only change some volatile data structures in the kernel space. Shouldn't we limit interrupt interface only between kernel and hardware, and spin-locks only among kernel objects? -Rong Chen Department of Computer Science University of Illinois at Urbana-Champaign
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Newsgroups: comp.os.mach Path: arc1-ca.pugleaf.net!utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!wuarchive!m.cs.uiuc.edu!rchen From: rchen@m.cs.uiuc.edu (Rong Chen) Subject: Re: interrupt and simple_locks Message-ID: <1991Apr4.035548.25439@m.cs.uiuc.edu> Organization: University of Illinois, Dept. of Comp. Sci., Urbana, IL References: <1991Apr3.184610.12580@m.cs.uiuc.edu> <4799@lectroid.sw.stratus.com> Distribution: comp Date: Thu, 4 Apr 91 03:55:48 GMT Lines: 18