Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6

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

diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index e2319f39988b042f364a73174a0d2ac254a5b60d..ac54ff56df80e407f927af322714c7c7b5ed41e2 100644 (file)
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -658,8 +658,11 @@ __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;
 }