Fix IO performance regression in sparc
Replace signalfd with signal handler/pipe. There is no way to interrupt
the CPU execution loop when a file descriptor becomes readable. This
results in a large performance regression in sparc emulation during
bootup.
This patch switches us to signal handler/pipe which was originally
suggested by Ian Jackson. The signal handler lets us interrupt the
CPU emulation loop while the write to a pipe lets us avoid the
select/signal race condition.
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5451 c046a42c-6fe2-441c-8c8c-71466251a162
diff --git a/vl.c b/vl.c
index 5fe288e..e8410a8 100644
--- a/vl.c
+++ b/vl.c
@@ -7475,6 +7475,19 @@
return 0;
}
+void qemu_service_io(void)
+{
+ CPUState *env = cpu_single_env;
+ if (env) {
+ cpu_interrupt(env, CPU_INTERRUPT_EXIT);
+#ifdef USE_KQEMU
+ if (env->kqemu_enabled) {
+ kqemu_cpu_interrupt(env);
+ }
+#endif
+ }
+}
+
/***********************************************************/
/* bottom halves (can be seen as timers which expire ASAP) */
