Module Name: src
Committed By: snj
Date: Thu Jul 14 06:56:03 UTC 2016
Modified Files:
src/sys/kern [netbsd-6]: kern_softint.c
Log Message:
Pull up following revision(s) (requested by knakahara in ticket #1356):
sys/kern/kern_softint.c: revision 1.42
fix the following softint parallel operation problem.
(0) softint handler "handler A" is established
(1) CPU#X does softint_schedule() for "handler A"
- the softhand_t is set SOFTINT_PENDING flag
- the softhand_t is NOT set SOFTINT_ACTIVE flag yet
(2) CPU#X begins other H/W interrupt processing
(3) CPU#Y does softint_disestablish() for "handler A"
- waits until softhand_t's SOFTINT_ACTIVE of all CPUs is clear
- the softhand_t is set not SOFTINT_ACTIVE but SOFTINT_PENDING,
so CPU#Y does not wait
- unset the function of "handler A"
(4) CPU#X does softint_execute()
- the function of "handler A" is already clear, so panic
To generate a diff of this commit:
cvs rdiff -u -r1.38.8.1 -r1.38.8.2 src/sys/kern/kern_softint.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
