From mboxrd@z Thu Jan  1 00:00:00 1970
From: yi li <liyi.dev@gmail.com>
Subject: A question about cpu_idle()
Date: Wed, 21 Oct 2009 11:07:38 +0800
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Hi RT users,

While reading patch-2.6.31.4-rt14, there is a patch for cpu_idle()
which I cannot understand.

Could anyone kindly enough to tell me what is patch used for?


diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index ebefb54..c8d0ece 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -152,9 +152,11 @@ void cpu_idle(void)
                }

                tick_nohz_restart_sched_tick();
-               preempt_enable_no_resched();
-               schedule();
+               local_irq_disable();
+               __preempt_enable_no_resched();
+               __schedule();
                preempt_disable();
+               local_irq_enable();
        }
 }

Regards,
-Yi