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

1 files changed, 4 insertions, 0 deletions

diff --git a/qemu-tool.c b/qemu-tool.c
index 63e205675c..87cc2949b2 100644
--- a/qemu-tool.c
+++ b/qemu-tool.c
@@ -26,6 +26,10 @@ struct QEMUBH
     void *opaque;
 };
 
+void qemu_service_io(void)
+{
+}
+
 void term_printf(const char *fmt, ...)
 {
 }