Hi, The discussion in a recent thread on Linux-PM has indicated that it's necessary to call pm_ops->finish() before devce_resume(), but enable_nonboot_cpus() has to be called before pm_ops->finish() (cf. http://lists.osdl.org/pipermail/linux-pm/2006-November/004164.html). For consistency, it seems reasonable to call disable_nonboot_cpus() after device_suspend(). This way the suspend code will remain symmetrical with respect to the resume code and it may allow us to speed up things in the future by suspending and resuming devices and/or saving the suspend image in many threads, but for this purpose we first need to make freeze_processes() SMP-safe. The following series of patches makes freeze_processes() SMP-safe and reorders the suspend and resume code so that nonboot CPUs are disabled after devices have been suspended and enabled before the devices are resumed. It also causes pm_ops->finish() to be called after enable_nonboot_cpus() wherever necessary. The first four patches have been tested on two different x86-64 SMP boxes and they don't seem to break anything. Still, if anyone can test them on some other SMP boxes (especially on i386 ones), please do so and tell me if there are any problems. The last patch is untested. All of the patches are against 2.6.19-rc6-mm1. Greetings, Rafael -- You never change things by fighting the existing reality. R. Buckminster Fuller
