We recently noticed that reboot of a 1024 cpu machine takes approx 16 minutes of just stopping the cpus. The slowdown was tracked to commit f96972f.
The current implementation does all the work of hot removing the cpus before halting the system. We are switching to just migrating to the reboot_cpu and then continuing with shutdown/reboot. The patch set is broken into five parts. The first two are planned for the stable release. The others move the halt/shutdown/reboot related functions to their own kernel/reboot.c file and then introduce the kernel boot parameter. Changes since -v5. - Moved the arch/x86 reboot= up to the generic kernel code. Changes since -v4. - Integrated Srivatsa S. Bhat creating cpu_hotplug_disable() function - Integrated comments by Srivatsa S. Bhat. - Made one more comment consistent with others in function. Changes since -v3. - Added a tested-by for the original reporter. - Fix compile failure found by Joe Perches. - Integrated comments by Joe Perches. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
