On Thu 01-08-13 17:49:59, Tejun Heo wrote:
> cgroup is in the process of converting to css (cgroup_subsys_state)
> from cgroup as the principal subsystem interface handle. This is
> mostly to prepare for the unified hierarchy support where css's will
> be created and destroyed dynamically but also helps cleaning up
> subsystem implementations as css is usually what they are interested
> in anyway.
>
> cftype->[un]register_event() is among the remaining couple interfaces
> which still use struct cgroup. Convert it to cgroup_subsys_state.
> The conversion is mostly mechanical and removes the last users of
> mem_cgroup_from_cont() and cg_to_vmpressure(), which are removed.
>
> Signed-off-by: Tejun Heo <t...@kernel.org>
> Cc: Johannes Weiner <han...@cmpxchg.org>
> Cc: Michal Hocko <mho...@suse.cz>
> Cc: Balbir Singh <bsinghar...@gmail.com>
Acked-by: Michal Hocko <mho...@suse.cz>
> ---
> include/linux/cgroup.h | 8 +++++---
> include/linux/vmpressure.h | 6 ++++--
> kernel/cgroup.c | 15 ++++++++-------
> mm/memcontrol.c | 21 ++++++++-------------
> mm/vmpressure.c | 21 +++++++++------------
> 5 files changed, 34 insertions(+), 37 deletions(-)
>
> diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
> index 6f6d87b..8f44411 100644
> --- a/include/linux/cgroup.h
> +++ b/include/linux/cgroup.h
> @@ -506,15 +506,17 @@ struct cftype {
> * you want to provide this functionality. Use eventfd_signal()
> * on eventfd to send notification to userspace.
> */
> - int (*register_event)(struct cgroup *cgrp, struct cftype *cft,
> - struct eventfd_ctx *eventfd, const char *args);
> + int (*register_event)(struct cgroup_subsys_state *css,
> + struct cftype *cft, struct eventfd_ctx *eventfd,
> + const char *args);
> /*
> * unregister_event() callback will be called when userspace
> * closes the eventfd or on cgroup removing.
> * This callback must be implemented, if you want provide
> * notification functionality.
> */
> - void (*unregister_event)(struct cgroup *cgrp, struct cftype *cft,
> + void (*unregister_event)(struct cgroup_subsys_state *css,
> + struct cftype *cft,
> struct eventfd_ctx *eventfd);
> };
>
> diff --git a/include/linux/vmpressure.h b/include/linux/vmpressure.h
> index 76be077..b239482 100644
> --- a/include/linux/vmpressure.h
> +++ b/include/linux/vmpressure.h
> @@ -33,10 +33,12 @@ extern void vmpressure_init(struct vmpressure *vmpr);
> extern struct vmpressure *memcg_to_vmpressure(struct mem_cgroup *memcg);
> extern struct cgroup_subsys_state *vmpressure_to_css(struct vmpressure
> *vmpr);
> extern struct vmpressure *css_to_vmpressure(struct cgroup_subsys_state *css);
> -extern int vmpressure_register_event(struct cgroup *cg, struct cftype *cft,
> +extern int vmpressure_register_event(struct cgroup_subsys_state *css,
> + struct cftype *cft,
> struct eventfd_ctx *eventfd,
> const char *args);
> -extern void vmpressure_unregister_event(struct cgroup *cg, struct cftype
> *cft,
> +extern void vmpressure_unregister_event(struct cgroup_subsys_state *css,
> + struct cftype *cft,
> struct eventfd_ctx *eventfd);
> #else
> static inline void vmpressure(gfp_t gfp, struct mem_cgroup *memcg,
> diff --git a/kernel/cgroup.c b/kernel/cgroup.c
> index c61b24f..e0ef58e 100644
> --- a/kernel/cgroup.c
> +++ b/kernel/cgroup.c
> @@ -159,9 +159,9 @@ struct css_id {
> */
> struct cgroup_event {
> /*
> - * Cgroup which the event belongs to.
> + * css which the event belongs to.
> */
> - struct cgroup *cgrp;
> + struct cgroup_subsys_state *css;
> /*
> * Control file which the event associated.
> */
> @@ -3948,11 +3948,12 @@ static void cgroup_event_remove(struct work_struct
> *work)
> {
> struct cgroup_event *event = container_of(work, struct cgroup_event,
> remove);
> - struct cgroup *cgrp = event->cgrp;
> + struct cgroup_subsys_state *css = event->css;
> + struct cgroup *cgrp = css->cgroup;
>
> remove_wait_queue(event->wqh, &event->wait);
>
> - event->cft->unregister_event(cgrp, event->cft, event->eventfd);
> + event->cft->unregister_event(css, event->cft, event->eventfd);
>
> /* Notify userspace the event is going away. */
> eventfd_signal(event->eventfd, 1);
> @@ -3972,7 +3973,7 @@ static int cgroup_event_wake(wait_queue_t *wait,
> unsigned mode,
> {
> struct cgroup_event *event = container_of(wait,
> struct cgroup_event, wait);
> - struct cgroup *cgrp = event->cgrp;
> + struct cgroup *cgrp = event->css->cgroup;
> unsigned long flags = (unsigned long)key;
>
> if (flags & POLLHUP) {
> @@ -4041,7 +4042,7 @@ static int cgroup_write_event_control(struct
> cgroup_subsys_state *css,
> event = kzalloc(sizeof(*event), GFP_KERNEL);
> if (!event)
> return -ENOMEM;
> - event->cgrp = cgrp;
> + event->css = css;
> INIT_LIST_HEAD(&event->list);
> init_poll_funcptr(&event->pt, cgroup_event_ptable_queue_proc);
> init_waitqueue_func_entry(&event->wait, cgroup_event_wake);
> @@ -4092,7 +4093,7 @@ static int cgroup_write_event_control(struct
> cgroup_subsys_state *css,
> goto out_put_cfile;
> }
>
> - ret = event->cft->register_event(cgrp, event->cft,
> + ret = event->cft->register_event(css, event->cft,
> event->eventfd, buffer);
> if (ret)
> goto out_put_cfile;
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index 95106a9..2885e3e 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -1034,11 +1034,6 @@ static void memcg_check_events(struct mem_cgroup
> *memcg, struct page *page)
> preempt_enable();
> }
>
> -static inline struct mem_cgroup *mem_cgroup_from_cont(struct cgroup *cont)
> -{
> - return mem_cgroup_from_css(cgroup_css(cont, mem_cgroup_subsys_id));
> -}
> -
> struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p)
> {
> /*
> @@ -5620,10 +5615,10 @@ static void mem_cgroup_oom_notify(struct mem_cgroup
> *memcg)
> mem_cgroup_oom_notify_cb(iter);
> }
>
> -static int mem_cgroup_usage_register_event(struct cgroup *cgrp,
> +static int mem_cgroup_usage_register_event(struct cgroup_subsys_state *css,
> struct cftype *cft, struct eventfd_ctx *eventfd, const char *args)
> {
> - struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
> + struct mem_cgroup *memcg = mem_cgroup_from_css(css);
> struct mem_cgroup_thresholds *thresholds;
> struct mem_cgroup_threshold_ary *new;
> enum res_type type = MEMFILE_TYPE(cft->private);
> @@ -5703,10 +5698,10 @@ unlock:
> return ret;
> }
>
> -static void mem_cgroup_usage_unregister_event(struct cgroup *cgrp,
> +static void mem_cgroup_usage_unregister_event(struct cgroup_subsys_state
> *css,
> struct cftype *cft, struct eventfd_ctx *eventfd)
> {
> - struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
> + struct mem_cgroup *memcg = mem_cgroup_from_css(css);
> struct mem_cgroup_thresholds *thresholds;
> struct mem_cgroup_threshold_ary *new;
> enum res_type type = MEMFILE_TYPE(cft->private);
> @@ -5782,10 +5777,10 @@ unlock:
> mutex_unlock(&memcg->thresholds_lock);
> }
>
> -static int mem_cgroup_oom_register_event(struct cgroup *cgrp,
> +static int mem_cgroup_oom_register_event(struct cgroup_subsys_state *css,
> struct cftype *cft, struct eventfd_ctx *eventfd, const char *args)
> {
> - struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
> + struct mem_cgroup *memcg = mem_cgroup_from_css(css);
> struct mem_cgroup_eventfd_list *event;
> enum res_type type = MEMFILE_TYPE(cft->private);
>
> @@ -5807,10 +5802,10 @@ static int mem_cgroup_oom_register_event(struct
> cgroup *cgrp,
> return 0;
> }
>
> -static void mem_cgroup_oom_unregister_event(struct cgroup *cgrp,
> +static void mem_cgroup_oom_unregister_event(struct cgroup_subsys_state *css,
> struct cftype *cft, struct eventfd_ctx *eventfd)
> {
> - struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
> + struct mem_cgroup *memcg = mem_cgroup_from_css(css);
> struct mem_cgroup_eventfd_list *ev, *tmp;
> enum res_type type = MEMFILE_TYPE(cft->private);
>
> diff --git a/mm/vmpressure.c b/mm/vmpressure.c
> index 2a8a736..13489b1 100644
> --- a/mm/vmpressure.c
> +++ b/mm/vmpressure.c
> @@ -74,11 +74,6 @@ static struct vmpressure *work_to_vmpressure(struct
> work_struct *work)
> return container_of(work, struct vmpressure, work);
> }
>
> -static struct vmpressure *cg_to_vmpressure(struct cgroup *cg)
> -{
> - return css_to_vmpressure(cgroup_css(cg, mem_cgroup_subsys_id));
> -}
> -
> static struct vmpressure *vmpressure_parent(struct vmpressure *vmpr)
> {
> struct cgroup_subsys_state *css = vmpressure_to_css(vmpr);
> @@ -283,7 +278,7 @@ void vmpressure_prio(gfp_t gfp, struct mem_cgroup *memcg,
> int prio)
>
> /**
> * vmpressure_register_event() - Bind vmpressure notifications to an eventfd
> - * @cg: cgroup that is interested in vmpressure notifications
> + * @css: css that is interested in vmpressure notifications
> * @cft: cgroup control files handle
> * @eventfd: eventfd context to link notifications with
> * @args: event arguments (used to set up a pressure level threshold)
> @@ -298,10 +293,11 @@ void vmpressure_prio(gfp_t gfp, struct mem_cgroup
> *memcg, int prio)
> * cftype).register_event, and then cgroup core will handle everything by
> * itself.
> */
> -int vmpressure_register_event(struct cgroup *cg, struct cftype *cft,
> - struct eventfd_ctx *eventfd, const char *args)
> +int vmpressure_register_event(struct cgroup_subsys_state *css,
> + struct cftype *cft, struct eventfd_ctx *eventfd,
> + const char *args)
> {
> - struct vmpressure *vmpr = cg_to_vmpressure(cg);
> + struct vmpressure *vmpr = css_to_vmpressure(css);
> struct vmpressure_event *ev;
> int level;
>
> @@ -329,7 +325,7 @@ int vmpressure_register_event(struct cgroup *cg, struct
> cftype *cft,
>
> /**
> * vmpressure_unregister_event() - Unbind eventfd from vmpressure
> - * @cg: cgroup handle
> + * @css: css handle
> * @cft: cgroup control files handle
> * @eventfd: eventfd context that was used to link vmpressure with the @cg
> *
> @@ -341,10 +337,11 @@ int vmpressure_register_event(struct cgroup *cg, struct
> cftype *cft,
> * cftype).unregister_event, and then cgroup core will handle everything
> * by itself.
> */
> -void vmpressure_unregister_event(struct cgroup *cg, struct cftype *cft,
> +void vmpressure_unregister_event(struct cgroup_subsys_state *css,
> + struct cftype *cft,
> struct eventfd_ctx *eventfd)
> {
> - struct vmpressure *vmpr = cg_to_vmpressure(cg);
> + struct vmpressure *vmpr = css_to_vmpressure(css);
> struct vmpressure_event *ev;
>
> mutex_lock(&vmpr->events_lock);
> --
> 1.8.3.1
>
--
Michal Hocko
SUSE Labs
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