From: Frederic Weisbecker Date: Fri, 7 Oct 2011 16:22:09 +0000 (+0200) Subject: x86: Call idle notifier after irq_enter() X-Git-Tag: v3.3-rc1~193^2^2~43 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=98ad1cc14a5c4fd658f9d72c6ba5c86dfd3ce0d5;p=pandora-kernel.git x86: Call idle notifier after irq_enter() Interrupts notify the idle exit state before calling irq_enter(). But the notifier code calls rcu_read_lock() and this is not allowed while rcu is in an extended quiescent state. We need to wait for irq_enter() -> rcu_idle_exit() to be called before doing so otherwise this results in a grumpy RCU: [ 0.099991] WARNING: at include/linux/rcupdate.h:194 __atomic_notifier_call_chain+0xd2/0x110() [ 0.099991] Hardware name: AMD690VM-FMH [ 0.099991] Modules linked in: [ 0.099991] Pid: 0, comm: swapper Not tainted 3.0.0-rc6+ #255 [ 0.099991] Call Trace: [ 0.099991] [] warn_slowpath_common+0x7a/0xb0 [ 0.099991] [] warn_slowpath_null+0x15/0x20 [ 0.099991] [] __atomic_notifier_call_chain+0xd2/0x110 [ 0.099991] [] atomic_notifier_call_chain+0x11/0x20 [ 0.099991] [] exit_idle+0x43/0x50 [ 0.099991] [] smp_apic_timer_interrupt+0x39/0xa0 [ 0.099991] [] apic_timer_interrupt+0x13/0x20 [ 0.099991] [] ? default_idle+0xa7/0x350 [ 0.099991] [] ? default_idle+0xa5/0x350 [ 0.099991] [] amd_e400_idle+0x8b/0x110 [ 0.099991] [] ? rcu_enter_nohz+0x8f/0x160 [ 0.099991] [] cpu_idle+0xb0/0x110 [ 0.099991] [] rest_init+0xe5/0x140 [ 0.099991] [] ? rest_init+0x48/0x140 [ 0.099991] [] start_kernel+0x3d1/0x3dc [ 0.099991] [] x86_64_start_reservations+0x131/0x135 [ 0.099991] [] x86_64_start_kernel+0xed/0xf4 Signed-off-by: Frederic Weisbecker Cc: Paul E. McKenney Cc: Ingo Molnar Cc: Thomas Gleixner Cc: H. Peter Anvin Cc: Andy Henroid Signed-off-by: Paul E. McKenney Reviewed-by: Josh Triplett --- Reading git-diff-tree failed