[PATCH] i386: paravirt CPU hypercall batching mode

[safe/jmp/linux-2.6] / arch / i386 / kernel / process.c

diff --git a/arch/i386/kernel/process.c b/arch/i386/kernel/process.c
index 23ae198..cfae587 100644 (file)
--- a/arch/i386/kernel/process.c
+++ b/arch/i386/kernel/process.c
@@ -670,14 +670,6 @@ struct task_struct fastcall * __switch_to(struct task_struct *prev_p, struct tas
        load_TLS(next, cpu);
 
        /*
-        * Restore %gs if needed (which is common)
-        */
-       if (prev->gs | next->gs)
-               loadsegment(gs, next->gs);
-
-       write_pda(pcurrent, next_p);
-
-       /*
         * Now maybe handle debug registers and/or IO bitmaps
         */
        if (unlikely((task_thread_info(next_p)->flags & _TIF_WORK_CTXSW)
@@ -686,6 +678,15 @@ struct task_struct fastcall * __switch_to(struct task_struct *prev_p, struct tas
 
        disable_tsc(prev_p, next_p);
 
+       /*
+        * Leave lazy mode, flushing any hypercalls made here.
+        * This must be done before restoring TLS segments so
+        * the GDT and LDT are properly updated, and must be
+        * done before math_state_restore, so the TS bit is up
+        * to date.
+        */
+       arch_leave_lazy_cpu_mode();
+
        /* If the task has used fpu the last 5 timeslices, just do a full
         * restore of the math state immediately to avoid the trap; the
         * chances of needing FPU soon are obviously high now
@@ -693,6 +694,14 @@ struct task_struct fastcall * __switch_to(struct task_struct *prev_p, struct tas
        if (next_p->fpu_counter > 5)
                math_state_restore();
 
+       /*
+        * Restore %gs if needed (which is common)
+        */
+       if (prev->gs | next->gs)
+               loadsegment(gs, next->gs);
+
+       write_pda(pcurrent, next_p);
+
        return prev_p;
 }