From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Smith Subject: [PATCH 2/3] c/r: Add CR_COPY() macro (v4) Date: Thu, 19 Mar 2009 15:41:18 -0400 Message-ID: <1237491679-14433-3-git-send-email-danms@us.ibm.com> References: <1237491679-14433-1-git-send-email-danms@us.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1237491679-14433-1-git-send-email-danms-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: containers-qjLDD68F18O7TbgM5vRIOg@public.gmane.org List-Id: containers.vger.kernel.org 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: Mar 04: . Removed semicolons . Added build-time check for __must_be_array in CR_COPY_ARRAY 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 1: https://lists.linux-foundation.org/pipermail/containers/2009-February/015821.html (all the way at the bottom) --- include/linux/checkpoint.h | 23 +++++++++++++++++++++++ 1 files changed, 23 insertions(+), 0 deletions(-) diff --git a/include/linux/checkpoint.h b/include/linux/checkpoint.h index e77393f..f748a75 100644 --- a/include/linux/checkpoint.h +++ b/include/linux/checkpoint.h @@ -120,6 +120,29 @@ static inline int cr_enabled(void) return 1; } +#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) + +/* Copy @count items from @b to @a if op is CR_CPT (otherwise, + * copy in the reverse direction) + */ +#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 (__must_be_array(a) && __must_be_array(b) && 0) + #else /* !CONFIG_CHECKPOINT_RESTART */ static inline void files_deny_checkpointing(struct files_struct *files) {} -- 1.6.1