[CRIU] [PATCH 02/11] lazy-pages: always compile uffd.c

[Adrian Reber]

Instead of adding ifdef's around the whole uffd.c content why didn't you
add your cr_lazy_pages()-without-UFFD implementation in the header file.

This would keep uffd.c free of ifdef's and should work just the way this
patch tries to implement it.

		Adrian

On Mon, Apr 11, 2016 at 09:19:45AM +0300, Mike Rapoport wrote:
> If CONFIG_HAS_UFFD is not defined an attempt to run the lazy pages daemon
> will result in error message
> 
> Signed-off-by: Mike Rapoport <rppt at linux.vnet.ibm.com>
> ---
>  criu/Makefile.crtools  |  2 --
>  criu/crtools.c         |  8 --------
>  criu/include/crtools.h |  4 ----
>  criu/uffd.c            | 12 ++++++++++++
>  4 files changed, 12 insertions(+), 14 deletions(-)
> 
> diff --git a/criu/Makefile.crtools b/criu/Makefile.crtools
> index d610d2f..79fd77a 100644
> --- a/criu/Makefile.crtools
> +++ b/criu/Makefile.crtools
> @@ -82,9 +82,7 @@ obj-y			+= pie-util-vdso.o
>  obj-y			+= vdso.o
>  endif
>  
> -ifeq ($(UFFD),1)
>  obj-y	+= uffd.o
> -endif
>  
>  PROTOBUF_GEN := $(SRC_DIR)/scripts/protobuf-gen.sh
>  
> diff --git a/criu/crtools.c b/criu/crtools.c
> index d4c5731..93ca90b 100644
> --- a/criu/crtools.c
> +++ b/criu/crtools.c
> @@ -317,9 +317,7 @@ int main(int argc, char *argv[], char *envp[])
>  		{ "external",			required_argument,	0, 1073	},
>  		{ "empty-ns",			required_argument,	0, 1074	},
>  		{ "unshare",			required_argument,	0, 1075 },
> -#ifdef CONFIG_HAS_UFFD
>  		{ "lazy-pages",			no_argument,		0, 1076 },
> -#endif
>  		{ "extra",			no_argument,		0, 1077	},
>  		{ "experimental",		no_argument,		0, 1078	},
>  		{ "all",			no_argument,		0, 1079	},
> @@ -582,11 +580,9 @@ int main(int argc, char *argv[], char *envp[])
>  			if (parse_unshare_arg(optarg))
>  				return -1;
>  			break;
> -#ifdef CONFIG_HAS_UFFD
>  		case 1076:
>  			opts.lazy_pages = true;
>  			break;
> -#endif
>  		case 'M':
>  			{
>  				char *aux;
> @@ -801,9 +797,7 @@ usage:
>  "  criu page-server\n"
>  "  criu service [<options>]\n"
>  "  criu dedup\n"
> -#ifdef CONFIG_HAS_UFFD
>  "  criu lazy-pages -D DIR [<options>]\n"
> -#endif
>  "\n"
>  "Commands:\n"
>  "  dump           checkpoint a process/tree identified by pid\n"
> @@ -843,12 +837,10 @@ usage:
>  "  --unshare FLAGS       what namespaces to unshare when restoring\n"
>  "  --freeze-cgroup\n"
>  "                        use cgroup freezer to collect processes\n"
> -#ifdef CONFIG_HAS_UFFD
>  "  --lazy-pages          restore pages on demand\n"
>  "                        this requires running a second instance of criu\n"
>  "                        in lazy-pages mode: 'criu lazy-pages -D DIR'\n"
>  "                        --lazy-pages and lazy-pages mode require userfaultfd\n"
> -#endif
>  "\n"
>  "* Special resources support:\n"
>  "  -x|--" USK_EXT_PARAM "inode,.." "      allow external unix connections (optionally can be assign socket's inode that allows one-sided dump)\n"
> diff --git a/criu/include/crtools.h b/criu/include/crtools.h
> index e58b2be..00b7621 100644
> --- a/criu/include/crtools.h
> +++ b/criu/include/crtools.h
> @@ -26,11 +26,7 @@ extern int convert_to_elf(char *elf_path, int fd_core);
>  extern int cr_check(void);
>  extern int cr_exec(int pid, char **opts);
>  extern int cr_dedup(void);
> -#ifdef CONFIG_HAS_UFFD
>  extern int cr_lazy_pages(void);
> -#else
> -static inline int cr_lazy_pages() { return 0; };
> -#endif /* CONFIG_HAS_UFFD */
>  extern int prepare_task_entries(void);
>  
>  extern int check_add_feature(char *arg);
> diff --git a/criu/uffd.c b/criu/uffd.c
> index 3752a8c..c7aea0f 100644
> --- a/criu/uffd.c
> +++ b/criu/uffd.c
> @@ -28,6 +28,8 @@
>  #include "include/cr_options.h"
>  #include "xmalloc.h"
>  
> +#ifdef CONFIG_HAS_UFFD
> +
>  #undef  LOG_PREFIX
>  #define LOG_PREFIX "lazy-pages: "
>  
> @@ -660,3 +662,13 @@ int cr_lazy_pages()
>  
>  	return handle_requests(uffd);
>  }
> +
> +#else /* CONFIG_HAS_UFFD */
> +
> +int cr_lazy_pages()
> +{
> +	pr_msg("userfaultfd system call is not supported, cannot start lazy-pages daemon\n");
> +	return -1;
> +}
> +
> +#endif /* CONFIG_HAS_UFFD */
> -- 
> 1.9.1
>