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, 0 insertions, 35 deletions

diff --git a/configure b/configure
index 9192fcf94b..ba80f1c557 100755
--- a/configure
+++ b/configure
@@ -113,8 +113,6 @@ aio="yes"
 nptl="yes"
 mixemu="no"
 bluez="yes"
-signalfd="no"
-eventfd="no"
 
 # OS specific
 targetos=`uname -s`
@@ -930,33 +928,6 @@ EOF
   fi
 fi
 
-##########################################
-# signalfd probe
-cat > $TMPC << EOF
-#define _GNU_SOURCE
-#include <unistd.h>
-#include <sys/syscall.h>
-#include <signal.h>
-int main(void) { return syscall(SYS_signalfd, -1, NULL, _NSIG / 8); }
-EOF
-
-if $cc $ARCH_CFLAGS -o $TMPE $TMPC 2> /dev/null ; then
-  signalfd=yes
-fi
-
-##########################################
-# eventfd probe
-cat > $TMPC << EOF
-#define _GNU_SOURCE
-#include <unistd.h>
-#include <sys/syscall.h>
-int main(void) { return syscall(SYS_eventfd, 0); }
-EOF
-
-if $cc $ARCH_CFLAGS -o $TMPE $TMPC 2> /dev/null ; then
-  eventfd=yes
-fi
-
 # Check if tools are available to build documentation.
 if [ -x "`which texi2html 2>/dev/null`" ] && \
    [ -x "`which pod2man 2>/dev/null`" ]; then
@@ -1297,12 +1268,6 @@ if test "$aio" = "yes" ; then
   echo "#define CONFIG_AIO 1" >> $config_h
   echo "CONFIG_AIO=yes" >> $config_mak
 fi
-if test "$signalfd" = "yes" ; then
-  echo "#define CONFIG_signalfd 1" >> $config_h
-fi
-if test "$eventfd" = "yes" ; then
-  echo "#define CONFIG_eventfd 1" >> $config_h
-fi
 
 # XXX: suppress that
 if [ "$bsd" = "yes" ] ; then