[CRIU] [PATCH 1/9] Adding --pre-dump-mode option

Andrei Vagin avagin at gmail.com
Wed Sep 25 19:15:31 MSK 2019


On Sun, Sep 22, 2019 at 09:54:50AM +0530, Abhishek Dubey wrote:
> Two modes of pre-dump algorithm:
>     1) splicing memory by parasite
>         --pre-dump-mode=splice (default)
>     2) using process_vm_readv syscall
>         --pre-dump-mode=read
> 
> Signed-off-by: Abhishek Dubey <dubeyabhishek777 at gmail.com>
> ---
>  Documentation/criu.txt    |  6 ++++++
>  criu/config.c             | 10 ++++++++++
>  criu/cr-dump.c            |  6 +++++-
>  criu/cr-service.c         | 13 +++++++++++++
>  criu/crtools.c            |  2 ++
>  criu/include/cr_options.h |  7 +++++++
>  criu/mem.c                | 13 ++++++++++++-
>  images/rpc.proto          |  6 ++++++
>  lib/c/criu.c              | 15 +++++++++++++++
>  lib/c/criu.h              |  7 +++++++
>  test/zdtm.py              |  9 ++++++++-
>  11 files changed, 91 insertions(+), 3 deletions(-)
> 
> diff --git a/Documentation/criu.txt b/Documentation/criu.txt
> index 28913a7..2729bc9 100644
> --- a/Documentation/criu.txt
> +++ b/Documentation/criu.txt
> @@ -156,6 +156,12 @@ In addition, *page-server* options may be specified.
>      Turn on memory changes tracker in the kernel. If the option is
>      not passed the memory tracker get turned on implicitly.
>  
> +*--pre-dump-mode*='mode'::
> +    There are two 'mode' to operate pre-dump algorithm. The 'splice' mode
> +    is parasite based, whereas 'read' mode is based on process_vm_readv
> +    syscall. The 'read' mode incurs reduced frozen time and reduced
> +    memory pressure as compared to 'splice' mode. Default is 'splice' mode.
> +
>  *dump*
>  ~~~~~~
>  Performs a checkpoint procedure.
> diff --git a/criu/config.c b/criu/config.c
> index 1a6d014..b252095 100644
> --- a/criu/config.c
> +++ b/criu/config.c
> @@ -276,6 +276,7 @@ void init_opts(void)
>  	opts.empty_ns = 0;
>  	opts.status_fd = -1;
>  	opts.log_level = DEFAULT_LOGLEVEL;
> +	opts.pre_dump_mode = PRE_DUMP_SPLICE;
>  }
>  
>  bool deprecated_ok(char *what)
> @@ -518,6 +519,7 @@ int parse_options(int argc, char **argv, bool *usage_error,
>  		BOOL_OPT("tls", &opts.tls),
>  		{"tls-no-cn-verify",		no_argument,		&opts.tls_no_cn_verify, true},
>  		{ "cgroup-yard",		required_argument,	0, 1096 },
> +		{ "pre-dump-mode",		required_argument,	0, 1097},
>  		{ },
>  	};
>  
> @@ -819,6 +821,14 @@ int parse_options(int argc, char **argv, bool *usage_error,
>  		case 1096:
>  			SET_CHAR_OPTS(cgroup_yard, optarg);
>  			break;
> +		case 1097:
> +			if (!strcmp("read", optarg)) {
> +				opts.pre_dump_mode = PRE_DUMP_READ;
> +			} else if (strcmp("splice", optarg)) {
> +				pr_err("Unable to parse value of --pre-dump-mode\n");
> +				return 1;
> +			}
> +			break;
>  		case 'V':
>  			pr_msg("Version: %s\n", CRIU_VERSION);
>  			if (strcmp(CRIU_GITID, "0"))
> diff --git a/criu/cr-dump.c b/criu/cr-dump.c
> index 119c82d..d4adfad 100644
> --- a/criu/cr-dump.c
> +++ b/criu/cr-dump.c
> @@ -1511,7 +1511,11 @@ static int cr_pre_dump_finish(int status)
>  			goto err;
>  
>  		mem_pp = dmpi(item)->mem_pp;
> -		ret = page_xfer_dump_pages(&xfer, mem_pp);
> +
> +		if (opts.pre_dump_mode == PRE_DUMP_READ)
> +			ret = 0;  /* Replace with call to optimized pre-dump */

I don't understand what this comment means...

> +		else
> +			ret = page_xfer_dump_pages(&xfer, mem_pp);
>  
>  		xfer.close(&xfer);
>  
> diff --git a/criu/cr-service.c b/criu/cr-service.c
> index 95ba2e5..392e9ac 100644
> --- a/criu/cr-service.c
> +++ b/criu/cr-service.c
> @@ -473,6 +473,19 @@ static int setup_opts_from_req(int sk, CriuOpts *req)
>  		opts.lazy_pages = req->lazy_pages;
>  	}
>  
> +	if (req->has_pre_dump_mode) {
> +		switch (req->pre_dump_mode) {
> +			case CRIU_PRE_DUMP_MODE__SPLICE:
> +				opts.pre_dump_mode = PRE_DUMP_SPLICE;
> +				break;
> +			case CRIU_PRE_DUMP_MODE__READ:
> +				opts.pre_dump_mode = PRE_DUMP_READ;
> +				break;
> +			default:
> +				goto err;
> +		}
> +	}
> +
>  	if (req->ps) {
>  		opts.port = (short)req->ps->port;
>  
> diff --git a/criu/crtools.c b/criu/crtools.c
> index c0de1c0..d908e7f 100644
> --- a/criu/crtools.c
> +++ b/criu/crtools.c
> @@ -446,6 +446,8 @@ usage:
>  "                        pages images of previous dump\n"
>  "                        when used on restore, as soon as page is restored, it\n"
>  "                        will be punched from the image\n"
> +"  --pre-dump-mode       splice - parasite based pre-dumping (default)\n"
> +"                        read   - process_vm_readv syscall based pre-dumping\n"
>  "\n"
>  "Page/Service server options:\n"
>  "  --address ADDR        address of server or service\n"
> diff --git a/criu/include/cr_options.h b/criu/include/cr_options.h
> index 5cbc56f..53bd5ed 100644
> --- a/criu/include/cr_options.h
> +++ b/criu/include/cr_options.h
> @@ -39,6 +39,12 @@ struct cg_root_opt {
>  };
>  
>  /*
> + * Pre-dump variants
> + */
> +#define PRE_DUMP_SPLICE		1		/* Pre-dump using parasite */
> +#define PRE_DUMP_READ			2		/* Pre-dump using process_vm_readv syscall */
> +
> +/*
>   * Cgroup management options.
>   */
>  #define CG_MODE_IGNORE		(0u << 0)	/* Zero is important here */
> @@ -81,6 +87,7 @@ struct cr_options {
>  	int			evasive_devices;
>  	int			link_remap_ok;
>  	int			log_file_per_pid;
> +	int			pre_dump_mode;
>  	bool			swrk_restore;
>  	char			*output;
>  	char			*root;
> diff --git a/criu/mem.c b/criu/mem.c
> index de66a62..911b9d2 100644
> --- a/criu/mem.c
> +++ b/criu/mem.c
> @@ -482,7 +482,18 @@ static int __parasite_dump_pages_seized(struct pstree_item *item,
>  	if (mdc->lazy)
>  		memcpy(pargs_iovs(args), pp->iovs,
>  		       sizeof(struct iovec) * pp->nr_iovs);
> -	ret = drain_pages(pp, ctl, args);
> +
> +	/*
> +	 * Faking drain_pages for pre-dump here. Actual drain_pages for pre-dump
> +	 * will happen after task unfreezing in cr_pre_dump_finish(). This is
> +	 * actual optimization which reduces time for which process was frozen
> +	 * during pre-dump.
> +	 */
> +	if (mdc->pre_dump && opts.pre_dump_mode == PRE_DUMP_READ)
> +		ret = 0;
> +	else
> +		ret = drain_pages(pp, ctl, args);
> +
>  	if (!ret && !mdc->pre_dump)
>  		ret = xfer_pages(pp, &xfer);
>  	if (ret)
> diff --git a/images/rpc.proto b/images/rpc.proto
> index c402259..fc2f1bc 100644
> --- a/images/rpc.proto
> +++ b/images/rpc.proto
> @@ -47,6 +47,11 @@ enum criu_cg_mode {
>  	DEFAULT = 6;
>  };
>  
> +enum criu_pre_dump_mode {
> +	SPLICE = 	1;
> +	READ =		2;
> +};
> +
>  message criu_opts {
>  	required int32			images_dir_fd	= 1;
>  	optional int32			pid		= 2; /* if not set on dump, will dump requesting process */
> @@ -121,6 +126,7 @@ message criu_opts {
>  	optional bool			tls			= 58;
>  	optional bool			tls_no_cn_verify	= 59;
>  	optional string			cgroup_yard		= 60;
> +	optional criu_pre_dump_mode	pre_dump_mode		= 61 [default = SPLICE];
>  /*	optional bool			check_mounts		= 128;	*/
>  }
>  
> diff --git a/lib/c/criu.c b/lib/c/criu.c
> index 14ddff2..fffb9fd 100644
> --- a/lib/c/criu.c
> +++ b/lib/c/criu.c
> @@ -336,6 +336,21 @@ int criu_set_parent_images(const char *path)
>  	return criu_local_set_parent_images(global_opts, path);
>  }
>  
> +int criu_local_set_pre_dump_mode(criu_opts *opts, enum criu_pre_dump_mode mode)
> +{
> +	opts->rpc->has_pre_dump_mode = true;
> +	if (mode == CRIU_PRE_DUMP_SPLICE || mode == CRIU_PRE_DUMP_READ) {
> +		opts->rpc->pre_dump_mode = mode;
> +		return 0;
> +	}
> +	return -1;
> +}
> +
> +int criu_set_pre_dump_mode(enum criu_pre_dump_mode mode)
> +{
> +	return criu_local_set_pre_dump_mode(global_opts, mode);
> +}
> +
>  void criu_local_set_track_mem(criu_opts *opts, bool track_mem)
>  {
>  	opts->rpc->has_track_mem = true;
> diff --git a/lib/c/criu.h b/lib/c/criu.h
> index cb37c52..22db0fd 100644
> --- a/lib/c/criu.h
> +++ b/lib/c/criu.h
> @@ -43,6 +43,11 @@ enum criu_cg_mode {
>  	CRIU_CG_MODE_DEFAULT,
>  };
>  
> +enum criu_pre_dump_mode {
> +	CRIU_PRE_DUMP_SPLICE =	1,
> +	CRIU_PRE_DUMP_READ =	2
> +};
> +
>  int criu_set_service_address(const char *path);
>  void criu_set_service_fd(int fd);
>  int criu_set_service_binary(const char *path);
> @@ -95,6 +100,7 @@ int criu_add_irmap_path(const char *path);
>  int criu_add_inherit_fd(int fd, const char *key);
>  int criu_add_external(const char *key);
>  int criu_set_page_server_address_port(const char *address, int port);
> +int criu_set_pre_dump_mode(enum criu_pre_dump_mode mode);
>  
>  /*
>   * The criu_notify_arg_t na argument is an opaque
> @@ -211,6 +217,7 @@ int criu_local_add_cg_yard(criu_opts *opts, const char *path);
>  int criu_local_add_inherit_fd(criu_opts *opts, int fd, const char *key);
>  int criu_local_add_external(criu_opts *opts, const char *key);
>  int criu_local_set_page_server_address_port(criu_opts *opts, const char *address, int port);
> +int criu_local_set_pre_dump_mode(criu_opts *opts, enum criu_pre_dump_mode mode);
>  
>  void criu_local_set_notify_cb(criu_opts *opts, int (*cb)(char *action, criu_notify_arg_t na));
>  
> diff --git a/test/zdtm.py b/test/zdtm.py
> index 98d113f..7fdb8a3 100755
> --- a/test/zdtm.py
> +++ b/test/zdtm.py
> @@ -1020,6 +1020,7 @@ class criu:
>          self.__tls = self.__tls_options() if opts['tls'] else []
>          self.__criu_bin = opts['criu_bin']
>          self.__crit_bin = opts['crit_bin']
> +        self.__pre_dump_mode = opts['pre_dump_mode']
>  
>      def fini(self):
>          if self.__lazy_migrate:
> @@ -1276,6 +1277,8 @@ class criu:
>              a_opts += ['--leave-stopped']
>          if self.__empty_ns:
>              a_opts += ['--empty-ns', 'net']
> +        if self.__pre_dump_mode:
> +            a_opts += ["--pre-dump-mode", "%s" % self.__pre_dump_mode]
>  
>          nowait = False
>          if self.__lazy_migrate and action == "dump":
> @@ -1865,7 +1868,7 @@ class Launcher:
>                'sat', 'script', 'rpc', 'lazy_pages', 'join_ns', 'dedup', 'sbs',
>                'freezecg', 'user', 'dry_run', 'noauto_dedup',
>                'remote_lazy_pages', 'show_stats', 'lazy_migrate', 'remote',
> -              'tls', 'criu_bin', 'crit_bin')
> +              'tls', 'criu_bin', 'crit_bin', 'pre_dump_mode')
>          arg = repr((name, desc, flavor, {d: self.__opts[d] for d in nd}))
>  
>          if self.__use_log:
> @@ -2512,6 +2515,10 @@ rp.add_argument("--criu-bin",
>  rp.add_argument("--crit-bin",
>                  help="Path to crit binary",
>                  default='../crit/crit')
> +rp.add_argument("--pre-dump-mode",
> +                help="Use splice or read mode of pre-dumping",
> +                choices=['splice', 'read'],
> +                default='splice')
>  
>  lp = sp.add_parser("list", help="List tests")
>  lp.set_defaults(action=list_tests)
> -- 
> 2.7.4
> 


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