[PATCH] x86: Don't use MWAIT on AMD Family 10

[linux-2.6-block.git] / arch / x86_64 / kernel / process.c

diff --git a/arch/x86_64/kernel/process.c b/arch/x86_64/kernel/process.c
index a418ee4c8c62a0d14102b22939dfa8c5b16d0f79..4f21765078b7a1520aceb07be78095e76b525f3e 100644 (file)
--- a/arch/x86_64/kernel/process.c
+++ b/arch/x86_64/kernel/process.c
@@ -109,7 +109,11 @@ void exit_idle(void)
 static void default_idle(void)
 {
        current_thread_info()->status &= ~TS_POLLING;
-       smp_mb__after_clear_bit();
+       /*
+        * TS_POLLING-cleared state must be visible before we
+        * test NEED_RESCHED:
+        */
+       smp_mb();
        local_irq_disable();
        if (!need_resched()) {
                /* Enables interrupts one instruction before HLT.
@@ -284,16 +288,18 @@ void __cpuinit select_idle_routine(const struct cpuinfo_x86 *c)
 
 static int __init idle_setup (char *str)
 {
-       if (!strncmp(str, "poll", 4)) {
+       if (!strcmp(str, "poll")) {
                printk("using polling idle threads.\n");
                pm_idle = poll_idle;
-       }
+       } else if (!strcmp(str, "mwait"))
+               force_mwait = 1;
+       else
+               return -1;
 
        boot_option_idle_override = 1;
-       return 1;
+       return 0;
 }
-
-__setup("idle=", idle_setup);
+early_param("idle", idle_setup);
 
 /* Prints also some state that isn't saved in the pt_regs */ 
 void __show_regs(struct pt_regs * regs)
@@ -378,14 +384,17 @@ void exit_thread(void)
 void flush_thread(void)
 {
        struct task_struct *tsk = current;
-       struct thread_info *t = current_thread_info();
 
-       if (t->flags & _TIF_ABI_PENDING) {
-               t->flags ^= (_TIF_ABI_PENDING | _TIF_IA32);
-               if (t->flags & _TIF_IA32)
+       if (test_tsk_thread_flag(tsk, TIF_ABI_PENDING)) {
+               clear_tsk_thread_flag(tsk, TIF_ABI_PENDING);
+               if (test_tsk_thread_flag(tsk, TIF_IA32)) {
+                       clear_tsk_thread_flag(tsk, TIF_IA32);
+               } else {
+                       set_tsk_thread_flag(tsk, TIF_IA32);
                        current_thread_info()->status |= TS_COMPAT;
+               }
        }
-       t->flags &= ~_TIF_DEBUG;
+       clear_tsk_thread_flag(tsk, TIF_DEBUG);
 
        tsk->thread.debugreg0 = 0;
        tsk->thread.debugreg1 = 0;