From: Richard Henderson <rth@twiddle.net>
To: qemu-devel@nongnu.org
Cc: Aurelien Jarno <aurelien@aurel32.net>
Subject: [Qemu-devel] [PATCH v2] qemu-timer: Check for usable fields for SIGEV_THREAD_ID
Date: Tue, 23 Oct 2012 07:33:00 +1000 [thread overview]
Message-ID: <1350941580-7807-1-git-send-email-rth@twiddle.net> (raw)
Older glibc (RHEL 5.x, Debian 5.x) does not have the _sigev_un._tid
member in its structure definition, while the accompanying kernel
headers do define SIGEV_THREAD_ID. We need configure to check for
both before using it.
Signed-off-by: Richard Henderson <rth@twiddle.net>
---
configure | 22 ++++++++++++++++++++++
qemu-timer.c | 4 ++--
2 files changed, 24 insertions(+), 2 deletions(-)
Version 2 avoids a warning in the test program.
r~
diff --git a/configure b/configure
index 9f33c7d..358a3aa 100755
--- a/configure
+++ b/configure
@@ -2813,6 +2813,24 @@ if compile_prog "" "" ; then
fi
##########################################
+# check if we have usable SIGEV_THREAD_ID
+
+sigev_thread_id=no
+cat > $TMPC << EOF
+#include <signal.h>
+int main(void) {
+ struct sigevent ev;
+ ev.sigev_notify = SIGEV_THREAD_ID;
+ ev._sigev_un._tid = 0;
+ asm volatile("" : : "g"(&ev));
+ return 0;
+}
+EOF
+if compile_prog "" "" ; then
+ sigev_thread_id=yes
+fi
+
+##########################################
# check if trace backend exists
$python "$source_path/scripts/tracetool.py" "--backend=$trace_backend" --check-backend > /dev/null 2> /dev/null
@@ -3159,6 +3177,7 @@ echo "preadv support $preadv"
echo "fdatasync $fdatasync"
echo "madvise $madvise"
echo "posix_madvise $posix_madvise"
+echo "sigev_thread_id $sigev_thread_id"
echo "uuid support $uuid"
echo "libcap-ng support $cap_ng"
echo "vhost-net support $vhost_net"
@@ -3443,6 +3462,9 @@ fi
if test "$posix_madvise" = "yes" ; then
echo "CONFIG_POSIX_MADVISE=y" >> $config_host_mak
fi
+if test "$sigev_thread_id" = "yes" ; then
+ echo "CONFIG_SIGEV_THREAD_ID=y" >> $config_host_mak
+fi
if test "$spice" = "yes" ; then
echo "CONFIG_SPICE=y" >> $config_host_mak
diff --git a/qemu-timer.c b/qemu-timer.c
index 908a103..ede84ff 100644
--- a/qemu-timer.c
+++ b/qemu-timer.c
@@ -494,12 +494,12 @@ static int dynticks_start_timer(struct qemu_alarm_timer *t)
memset(&ev, 0, sizeof(ev));
ev.sigev_value.sival_int = 0;
ev.sigev_notify = SIGEV_SIGNAL;
-#ifdef SIGEV_THREAD_ID
+#ifdef CONFIG_SIGEV_THREAD_ID
if (qemu_signalfd_available()) {
ev.sigev_notify = SIGEV_THREAD_ID;
ev._sigev_un._tid = qemu_get_thread_id();
}
-#endif /* SIGEV_THREAD_ID */
+#endif /* CONFIG_SIGEV_THREAD_ID */
ev.sigev_signo = SIGALRM;
if (timer_create(CLOCK_REALTIME, &ev, &host_timer)) {
--
1.7.11.7
next reply other threads:[~2012-10-22 21:33 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-22 21:33 Richard Henderson [this message]
2012-10-29 14:34 ` [Qemu-devel] [PATCH v2] qemu-timer: Check for usable fields for SIGEV_THREAD_ID Aurelien Jarno
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