core/cpu: do not inline cpu_relax

The added nops now push it up in size, and -Os uninlines it for every
compilation unit that calls it more than once, so it's much better to
just uninline.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Stewart Smith <stewart@linux.ibm.com>

1 files changed, 12 insertions, 0 deletions

diff --git a/core/cpu.c b/core/cpu.c
index 1542776..ad64b6e 100644
--- a/core/cpu.c
+++ b/core/cpu.c
@@ -91,6 +91,18 @@ unsigned long __attrconst cpu_emergency_stack_top(unsigned int pir)
 		NORMAL_STACK_SIZE + EMERGENCY_STACK_SIZE - STACK_TOP_GAP;
 }
 
+void __nomcount cpu_relax(void)
+{
+	/* Relax a bit to give sibling threads some breathing space */
+	smt_lowest();
+	asm volatile("nop; nop; nop; nop;\n"
+		     "nop; nop; nop; nop;\n"
+		     "nop; nop; nop; nop;\n"
+		     "nop; nop; nop; nop;\n");
+	smt_medium();
+	barrier();
+}
+
 static void cpu_wake(struct cpu_thread *cpu)
 {
 	/* Is it idle ? If not, no need to wake */