Commits
Li Zhong committed 21acd0e4df0
KVM: PPC: Book 3S: XICS: Don't lock twice when checking for resend This patch improves the code that takes lock twice to check the resend flag and do the actual resending, by checking the resend flag locklessly, and add a boolean parameter check_resend to icp_[rm_]deliver_irq(), so the resend flag can be checked in the lock when doing the delivery. We need make sure when we clear the ics's bit in the icp's resend_map, we don't miss the resend flag of the irqs that set the bit. It could be ordered through the barrier in test_and_clear_bit(), and a newly added wmb between setting irq's resend flag, and icp's resend_map. Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>