From e85ca71aadcc42a3f7cc90e6cff96c28f1c54290 Mon Sep 17 00:00:00 2001 From: attilio Date: Thu, 13 Aug 2009 17:09:45 +0000 Subject: * Completely Remove the option STOP_NMI from the kernel. This option has proven to have a good effect when entering KDB by using a NMI, but it completely violates all the good rules about interrupts disabled while holding a spinlock in other occasions. This can be the cause of deadlocks on events where a normal IPI_STOP is expected. * Adds an new IPI called IPI_STOP_HARD on all the supported architectures. This IPI is responsible for sending a stop message among CPUs using a privileged channel when disponible. In other cases it just does match a normal IPI_STOP. Right now the IPI_STOP_HARD functionality uses a NMI on ia32 and amd64 architectures, while on the other has a normal IPI_STOP effect. It is responsibility of maintainers to eventually implement an hard stop when necessary and possible. * Use the new IPI facility in order to implement a new userend SMP kernel function called stop_cpus_hard(). That is specular to stop_cpu() but it does use the privileged channel for the stopping facility. * Let KDB use the newly introduced function stop_cpus_hard() and leave stop_cpus() for all the other cases * Disable interrupts on CPU0 when starting the process of APs suspension. * Style cleanup and comments adding This patch should fix the reboot/shutdown deadlocks many users are constantly reporting on mailing lists. Please don't forget to update your config file with the STOP_NMI option removal Reviewed by: jhb Tested by: pho, bz, rink Approved by: re (kib) --- sys/i386/conf/NOTES | 1 - 1 file changed, 1 deletion(-) (limited to 'sys/i386/conf/NOTES') diff --git a/sys/i386/conf/NOTES b/sys/i386/conf/NOTES index f442e24..f772b25 100644 --- a/sys/i386/conf/NOTES +++ b/sys/i386/conf/NOTES @@ -49,7 +49,6 @@ options MP_WATCHDOG # Debugging options. # -options STOP_NMI # Stop CPUS using NMI instead of IPI options COUNT_XINVLTLB_HITS # Counters for TLB events options COUNT_IPIS # Per-CPU IPI interrupt counters -- cgit v1.1