Messages in this thread | | | Date | Thu, 15 Dec 2005 15:38:18 -0500 | From | Jeff Dike <> | Subject | Re: [PATCH 1/19] MUTEX: Introduce simple mutex implementation |
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On Thu, Dec 15, 2005 at 09:45:10AM -0800, Luck, Tony wrote: > There was a USENIX paper a couple of decades ago that described how > to do a fast s/w disable of interrupts on machines where really disabling > interrupts was expensive. The rough gist was that the spl[1-7]() > functions would just set a flag in memory to hold the desired interrupt > mask. If an interrupt actually occurred when it was s/w blocked, the > handler would set a pending flag, and just rfi with interrupts disabled. > Then the splx() code checked to see whether there was a pending interrupt > and dealt with it if there was.
... and this is currently implemented (but not yet merged to mainline) in UML.
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