This driver has one serious and one mild bug in its hot plug handling. First, whenever a new CPU goes on line, if the call to cpuidle_register_driver() should fail (say, due to lack of memory), then the driver frees its per-CPU region. On the *next* CPU_ONLINE event, the driver will happily use the region again and even free it again if the failure repeats.
Second, for each new on line CPU, a device is registered with the cpuidle layer. However, when a CPU goes down, its device is never unregistered, even if the module exits. Although this driver may not (yet?) be a built as a module, still this patch series cleans up the exit path in order to make the resource allocations clear. Richard Cochran (10): intel_idle: remove useless return from void function. intel_idle: Fix a helper function's return value. intel_idle: Remove redundant initialization calls. intel_idle: Fix deallocation order on the driver exit path. intel_idle: Fix dangling registration on error path. intel_idle: Avoid a double free of the per-CPU data. intel_idle: Setup the timer broadcast only on successful driver load. intel_idle: Don't overreact to a cpuidle registration failure. intel_idle: Propagate hot plug errors. intel_idle: Clean up all registered devices on exit. drivers/idle/intel_idle.c | 61 ++++++++++++++++++++++++----------------------- 1 file changed, 31 insertions(+), 30 deletions(-) -- 2.1.4
