x86-preempt-rt-scheduling-support-32bit.patch

From f885634adab8347527f902b8b54abc17cb9991d7 Mon Sep 17 00:00:00 2001
From: Ingo Molnar <mingo@elte.hu>
Date: Fri, 3 Jul 2009 08:30:06 -0500
Subject: [PATCH] x86: preempt-rt scheduling support (32bit)

commit 94b3cbf2548a023b4187e252043eac367f84740c in tip.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S
index 44a8e0d..57d3849 100644
--- a/arch/x86/kernel/entry_32.S
+++ b/arch/x86/kernel/entry_32.S
@@ -375,13 +375,13 @@ END(ret_from_exception)
 ENTRY(resume_kernel)
 	DISABLE_INTERRUPTS(CLBR_ANY)
 	cmpl $0,TI_preempt_count(%ebp)	# non-zero preempt_count ?
-	jnz restore_all
+	jnz restore_nocheck
 need_resched:
 	movl TI_flags(%ebp), %ecx	# need_resched set ?
 	testb $_TIF_NEED_RESCHED, %cl
-	jz restore_all
+	jz restore_nocheck
 	testl $X86_EFLAGS_IF,PT_EFLAGS(%esp)	# interrupts off (exception path) ?
-	jz restore_all
+	jz restore_nocheck
 	call preempt_schedule_irq
 	jmp need_resched
 END(resume_kernel)
@@ -639,12 +639,9 @@ work_pending:
 	testb $_TIF_NEED_RESCHED, %cl
 	jz work_notifysig
 work_resched:
-	call schedule
+	call __schedule
 	LOCKDEP_SYS_EXIT
-	DISABLE_INTERRUPTS(CLBR_ANY)	# make sure we don't miss an interrupt
-					# setting need_resched or sigpending
-					# between sampling and the iret
-	TRACE_IRQS_OFF
+
 	movl TI_flags(%ebp), %ecx
 	andl $_TIF_WORK_MASK, %ecx	# is there any work to be done other
 					# than syscall tracing?
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index 489cb0e..46f5881 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -112,10 +112,12 @@ void cpu_idle(void)
 			pm_idle();
 			start_critical_timings();
 		}
+		local_irq_disable();
 		tick_nohz_restart_sched_tick();
 		__preempt_enable_no_resched();
-		schedule();
+		__schedule();
 		preempt_disable();
+		local_irq_enable();
 	}
 }
 
-- 
1.7.1.1