xorg-x11-server/0001-xwayland-shm-block-signals-during-fallocate.patch
Hans de Goede 7084842c1c Update to 1.19.0-rc2
- Fix (hopefully) various crashes in FlushAllOutput() (rhbz#1382444)
- Fix Xwayland crashing in glamor on non glamor capable hw (rhbz#1390018)
2016-11-03 13:21:47 +01:00

55 lines
1.6 KiB
Diff

From 4cfee398726adf89db4b632ade7d6cab8b78282e Mon Sep 17 00:00:00 2001
From: Ian Ray <ian.ray@ge.com>
Date: Wed, 25 May 2016 10:41:53 +0300
Subject: [PATCH xserver v2 1/7] xwayland-shm: block signals during fallocate
posix_fallocate() does an explicit rollback if it gets EINTR, and
this is a problem on slow systems because when the allocation size
is sufficiently large posix_fallocate() will always be interrupted
by the smart scheduler's SIGALRM.
Changes since v1 - big comment in the code to explain what is going on
Reviewed-by: Adam Jackson <ajax@redhat.com>
Signed-off-by: Ian Ray <ian.ray@ge.com>
Acked-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Acked-by: Daniel Stone <daniels@collabora.com>
---
hw/xwayland/xwayland-shm.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/hw/xwayland/xwayland-shm.c b/hw/xwayland/xwayland-shm.c
index daf6148..452d1f5 100644
--- a/hw/xwayland/xwayland-shm.c
+++ b/hw/xwayland/xwayland-shm.c
@@ -28,6 +28,8 @@
#include <dix-config.h>
#endif
+#include "os.h"
+
#include "xwayland.h"
#include <sys/mman.h>
@@ -139,9 +141,17 @@ os_create_anonymous_file(off_t size)
return -1;
#ifdef HAVE_POSIX_FALLOCATE
+ /*
+ * posix_fallocate does an explicit rollback if it gets EINTR.
+ * Temporarily block signals to allow the call to succeed on
+ * slow systems where the smart scheduler's SIGALRM prevents
+ * large allocation attempts from ever succeeding.
+ */
+ OsBlockSignals();
do {
ret = posix_fallocate(fd, 0, size);
} while (ret == EINTR);
+ OsReleaseSignals();
if (ret != 0) {
close(fd);
--
2.9.3