Module Name: src
Committed By: mrg
Date: Thu Jan 27 05:31:14 UTC 2011
Modified Files:
src/sys/arch/sparc/sparc: cpu.c cpuvar.h intr.c
Log Message:
to quote a new comment:
* There's a deadlock potential between multiple CPUs trying
* to xcall() at the same time, and the thread that loses the
* race to get xpmsg_lock is at an IPL above the incoming IPI
* IPL level, so it sits around waiting to take the lock while
* the other CPU is waiting for this CPU to handle the IPI and
* mark it as completed.
*
* If we fail to get the mutex, and we're at high enough IPL,
* call xcallintr() if there is a valid msg.tag.
this seems to fix the xcall() failed to ping cpus problem.
idea from martin, tested by macallan and myself.
To generate a diff of this commit:
cvs rdiff -u -r1.225 -r1.226 src/sys/arch/sparc/sparc/cpu.c
cvs rdiff -u -r1.84 -r1.85 src/sys/arch/sparc/sparc/cpuvar.h
cvs rdiff -u -r1.109 -r1.110 src/sys/arch/sparc/sparc/intr.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
