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From: Li Zefan <lizefan-hv44wF8Li93QT0dZR+AlfA@public•gmane.org>
To: Daniel Wagner <wagi-kQCPcA+X3s7YtjvyW6yDsg@public•gmane.org>
Cc: <netdev-u79uwXL29TY76Z2rM5mHXA@public•gmane.org>,
	<cgroups-u79uwXL29TY76Z2rM5mHXA@public•gmane.org>,
	Daniel Wagner
	<daniel.wagner-98C5kh4wR6ohFhg+JK9F0w@public•gmane.org>,
	Gao feng <gaofeng-BthXqXjhjHXQFUHtdCDX3A@public•gmane.org>,
	Jamal Hadi Salim <jhs-jkUAjuhPggJWk0Htik3J/w@public•gmane.org>,
	John Fastabend
	<john.r.fastabend-ral2JQCrhuEAvxtiuMwx3w@public•gmane.org>,
	Neil Horman <nhorman-2XuSBdqkA4R54TAoqtyWWQ@public•gmane.org>
Subject: Re: [PATCH v4 4/8] cgroup: Remove CGROUP_BUILTIN_SUBSYS_COUNT
Date: Thu, 13 Sep 2012 14:41:03 +0800	[thread overview]
Message-ID: <50517FFF.4030106@huawei.com> (raw)
In-Reply-To: <1347459128-32236-5-git-send-email-wagi-kQCPcA+X3s7YtjvyW6yDsg@public.gmane.org>

> @@ -1321,11 +1321,13 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts)
>  	 * take duplicate reference counts on a subsystem that's already used,
>  	 * but rebind_subsystems handles this case.
>  	 */
> -	for (i = CGROUP_BUILTIN_SUBSYS_COUNT; i < CGROUP_SUBSYS_COUNT; i++) {
> +	for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) {
>  		unsigned long bit = 1UL << i;
>  
>  		if (!(bit & opts->subsys_mask))
>  			continue;
> +		if (!subsys[i]->module)
> +			continue;

This check is not necessary. If it's builtin, try_module_get() will just return 1, and
we're fine.

>  		if (!try_module_get(subsys[i]->module)) {
>  			module_pin_failed = true;
>  			break;
> @@ -1337,12 +1339,14 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts)
>  		 * raced with a module_delete call, and to the user this is
>  		 * essentially a "subsystem doesn't exist" case.
>  		 */
> -		for (i--; i >= CGROUP_BUILTIN_SUBSYS_COUNT; i--) {
> +		for (i--; i >= 0; i--) {
>  			/* drop refcounts only on the ones we took */
>  			unsigned long bit = 1UL << i;
>  
>  			if (!(bit & opts->subsys_mask))
>  				continue;
> +			if (!subsys[i]->module)
> +				continue;

ditto

>  			module_put(subsys[i]->module);
>  		}
>  		return -ENOENT;
> @@ -1354,11 +1358,13 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts)
>  static void drop_parsed_module_refcounts(unsigned long subsys_mask)
>  {
>  	int i;
> -	for (i = CGROUP_BUILTIN_SUBSYS_COUNT; i < CGROUP_SUBSYS_COUNT; i++) {
> +	for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) {
>  		unsigned long bit = 1UL << i;
>  
>  		if (!(bit & subsys_mask))
>  			continue;
> +		if (!subsys[i]->module)
> +			continue;

ditto

>  		module_put(subsys[i]->module);
>  	}
>  }
> @@ -1437,6 +1443,7 @@ static void init_cgroup_housekeeping(struct cgroup *cgrp)
>  	INIT_LIST_HEAD(&cgrp->event_list);
>  	spin_lock_init(&cgrp->event_list_lock);
>  	simple_xattrs_init(&cgrp->xattrs);
> +	memset(cgrp->subsys, 0, sizeof(cgrp->subsys));

This seems an unrelated change, and is redundant. Am I missing something?

>  }
>  

  parent reply	other threads:[~2012-09-13  6:41 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-09-12 14:12 [PATCH v4 0/8] cgroup: Assign subsystem IDs during compile time Daniel Wagner
2012-09-12 14:12 ` [PATCH v4 2/8] cgroup: net_cls: Do not define task_cls_classid() when not selected Daniel Wagner
2012-09-13  6:35   ` Li Zefan
2012-09-12 14:12 ` [PATCH v4 3/8] cgroup: net_prio: Do not define task_netpioidx() " Daniel Wagner
     [not found]   ` <1347459128-32236-4-git-send-email-wagi-kQCPcA+X3s7YtjvyW6yDsg@public.gmane.org>
2012-09-13  6:36     ` Li Zefan
2012-09-12 14:12 ` [PATCH v4 4/8] cgroup: Remove CGROUP_BUILTIN_SUBSYS_COUNT Daniel Wagner
     [not found]   ` <1347459128-32236-5-git-send-email-wagi-kQCPcA+X3s7YtjvyW6yDsg@public.gmane.org>
2012-09-13  6:41     ` Li Zefan [this message]
     [not found]       ` <50517FFF.4030106-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>
2012-09-13  6:57         ` Daniel Wagner
     [not found]           ` <505183E3.3030409-kQCPcA+X3s7YtjvyW6yDsg@public.gmane.org>
2012-09-13  7:14             ` Li Zefan
     [not found]               ` <505187C8.9030001-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>
2012-09-13  7:38                 ` Daniel Wagner
2012-09-12 14:12 ` [PATCH v4 6/8] cgroup: Do not depend on a given order when populating the subsys array Daniel Wagner
     [not found]   ` <1347459128-32236-7-git-send-email-wagi-kQCPcA+X3s7YtjvyW6yDsg@public.gmane.org>
2012-09-13  6:42     ` Li Zefan
2012-09-12 14:12 ` [PATCH v4 7/8] cgroup: Assign subsystem IDs during compile time Daniel Wagner
     [not found]   ` <1347459128-32236-8-git-send-email-wagi-kQCPcA+X3s7YtjvyW6yDsg@public.gmane.org>
2012-09-13  6:45     ` Li Zefan
2012-09-12 14:12 ` [PATCH v4 8/8] cgroup: Define CGROUP_SUBSYS_COUNT according the configuration Daniel Wagner
     [not found]   ` <1347459128-32236-9-git-send-email-wagi-kQCPcA+X3s7YtjvyW6yDsg@public.gmane.org>
2012-09-13  6:46     ` Li Zefan
     [not found] ` <1347459128-32236-1-git-send-email-wagi-kQCPcA+X3s7YtjvyW6yDsg@public.gmane.org>
2012-09-12 14:12   ` [PATCH v4 1/8] cgroup: net_cls: Move sock_update_classid() declaration to cls_cgroup.h Daniel Wagner
     [not found]     ` <1347459128-32236-2-git-send-email-wagi-kQCPcA+X3s7YtjvyW6yDsg@public.gmane.org>
2012-09-13  6:34       ` Li Zefan
2012-09-12 14:12   ` [PATCH v4 5/8] cgroup: Wrap subsystem selection macro Daniel Wagner
     [not found]     ` <1347459128-32236-6-git-send-email-wagi-kQCPcA+X3s7YtjvyW6yDsg@public.gmane.org>
2012-09-13  6:41       ` Li Zefan
2012-09-12 18:56   ` [PATCH v4 0/8] cgroup: Assign subsystem IDs during compile time Tejun Heo
2012-09-13 14:01   ` Neil Horman
2012-09-13 18:13 ` Tejun Heo

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