[PATCH 2/3] c/r: Add CR_COPY() macro (v3)

Dan Smith
2009-03-03T15:57:00Z

As suggested by Dave[1], this provides us a way to make the copy-in and
copy-out processes symmetric. CR_COPY_ARRAY() provides us a way to do
the same thing but for arrays. It's not critical, but it helps us unify
the checkpoint and restart paths for some things.

Changelog:
Feb 27:
. Changed CR_COPY() to use assignment, eliminating the need
for the CR_COPY_BIT() macro
. Add CR_COPY_ARRAY() macro to help copying register arrays,
etc
. Move the macro definitions inside the CR #ifdef
Feb 25:
. Changed WARN_ON() to BUILD_BUG_ON()

Signed-off-by: Dan Smith <danms@us.ibm.com>

1: https://lists.linux-foundation.org/pipermail/containers/2009-February/015821.html (all the way at the bottom)
---
include/linux/checkpoint.h | 20 ++++++++++++++++++++
1 files changed, 20 insertions(+), 0 deletions(-)

diff --git a/include/linux/checkpoint.h b/include/linux/checkpoint.h
index 217cf6e..735668f 100644
--- a/include/linux/checkpoint.h
+++ b/include/linux/checkpoint.h
@@ -142,6 +142,26 @@ static inline void __task_deny_checkpointing(struct task_struct *task,
#define task_deny_checkpointing(p) \
__task_deny_checkpointing(p, __FILE__, __LINE__)

+#define CR_CPT 1
+#define CR_RST 2
+
+#define CR_COPY(op, a, b) \
+ do { \
+ if (op == CR_CPT) \
+ a = b; \
+ else \
+ b = a; \
+ } while (0);
+
+#define CR_COPY_ARRAY(op, a, b, count) \
+ do { \
+ BUILD_BUG_ON(sizeof(*a) != sizeof(*b)); \
+ if (op == CR_CPT) \
+ memcpy(a, b, count * sizeof(*a)); \
+ else \
+ memcpy(b, a, count * sizeof(*a)); \
+ } while (0);
+
#else

static inline void task_deny_checkpointing(struct task_struct *task) {}
--
1.6.1