[libvirt] [PATCH]lxc: don't do duplicate work when getting pagesize

[Chen Hanxiao]

From: Chen Hanxiao <chenhanxiao at cn.fujitsu.com>

Don't do duplicate work when getting pagesize.
With some debug logs added.

Signed-off-by: Chen Hanxiao <chenhanxiao at cn.fujitsu.com>
---
 src/lxc/lxc_container.c | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/src/lxc/lxc_container.c b/src/lxc/lxc_container.c
index 255c711..e85d01c 100644
--- a/src/lxc/lxc_container.c
+++ b/src/lxc/lxc_container.c
@@ -144,6 +144,7 @@ int lxcContainerHasReboot(void)
     int cmd, v;
     int status;
     char *tmp;
+    int stacksize = getpagesize() * 4;
 
     if (virFileReadAll("/proc/sys/kernel/ctrl-alt-del", 10, &buf) < 0)
         return -1;
@@ -160,10 +161,12 @@ int lxcContainerHasReboot(void)
     VIR_FREE(buf);
     cmd = v ? LINUX_REBOOT_CMD_CAD_ON : LINUX_REBOOT_CMD_CAD_OFF;
 
-    if (VIR_ALLOC_N(stack, getpagesize() * 4) < 0)
+    if (VIR_ALLOC_N(stack, stacksize) < 0) {
+        VIR_DEBUG("Unable to allocate stack");
         return -1;
+    }
 
-    childStack = stack + (getpagesize() * 4);
+    childStack = stack + stacksize;
 
     cpid = clone(lxcContainerRebootChild, childStack, flags, &cmd);
     VIR_FREE(stack);
@@ -2011,8 +2014,10 @@ int lxcContainerStart(virDomainDefPtr def,
     };
 
     /* allocate a stack for the container */
-    if (VIR_ALLOC_N(stack, stacksize) < 0)
+    if (VIR_ALLOC_N(stack, stacksize) < 0) {
+        VIR_DEBUG("Unable to allocate stack");
         return -1;
+    }
     stacktop = stack + stacksize;
 
     cflags = CLONE_NEWPID|CLONE_NEWNS|CLONE_NEWUTS|CLONE_NEWIPC|SIGCHLD;
@@ -2060,6 +2065,7 @@ int lxcContainerAvailable(int features)
     int cpid;
     char *childStack;
     char *stack;
+    int stacksize = getpagesize() * 4;
 
     if (features & LXC_CONTAINER_FEATURE_USER)
         flags |= CLONE_NEWUSER;
@@ -2067,12 +2073,12 @@ int lxcContainerAvailable(int features)
     if (features & LXC_CONTAINER_FEATURE_NET)
         flags |= CLONE_NEWNET;
 
-    if (VIR_ALLOC_N(stack, getpagesize() * 4) < 0) {
+    if (VIR_ALLOC_N(stack, stacksize) < 0) {
         VIR_DEBUG("Unable to allocate stack");
         return -1;
     }
 
-    childStack = stack + (getpagesize() * 4);
+    childStack = stack + stacksize;
 
     cpid = clone(lxcContainerDummyChild, childStack, flags, NULL);
     VIR_FREE(stack);
-- 
1.8.2.1