Merge branch 'linus' into tracing/ftrace

[linux-2.6-omap-h63xx.git] / arch / x86 / kernel / process_64.c

diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index dd349c92f051f73ef9a0491309edce0fc056e56f..dc534f40c8d3c68a810c7addf6ae69deb88b08f9 100644 (file)
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -661,8 +661,11 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
        /* 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
+        *
+        * tsk_used_math() checks prevent calling math_state_restore(),
+        * which can sleep in the case of !tsk_used_math()
         */
-       if (next_p->fpu_counter>5)
+       if (tsk_used_math(next_p) && next_p->fpu_counter > 5)
                math_state_restore();
        return prev_p;
 }