Re: [PATCH 09/13] mm: memcontrol: generalize the socket accounting jump label
From: Jason Baron
Date: Mon Nov 30 2015 - 17:28:55 EST
On 11/30/2015 04:50 PM, Johannes Weiner wrote:
> On Mon, Nov 30, 2015 at 04:08:18PM -0500, Jason Baron wrote:
>> We're trying to move to the updated API, so this should be:
>> static_branch_unlikely(&memcg_sockets_enabled_key)
>>
>> see: include/linux/jump_label.h for details.
>
> Good point. There is another struct static_key in there as well. How
> about the following on top of this series?
>
Looks fine - you may be able to make use of
'static_branch_enable()/disable()' instead of the inc()/dec() to simply
set the branch direction, if you think its more readable. Although I
didn't look to see if it would be racy here.
Thanks,
-Jason
> ---
> From b784aa0323628d43272e13a67ead2a2ce0e93ea6 Mon Sep 17 00:00:00 2001
> From: Johannes Weiner <hannes@xxxxxxxxxxx>
> Date: Mon, 30 Nov 2015 16:41:38 -0500
> Subject: [PATCH] mm: memcontrol: switch to the updated jump-label API
>
> According to <linux/jump_label.h> the direct use of struct static_key
> is deprecated. Update the socket and slab accounting code accordingly.
>
> Reported-by: Jason Baron <jbaron@xxxxxxxxxx>
> Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx>
> ---
> include/linux/memcontrol.h | 8 ++++----
> mm/memcontrol.c | 12 ++++++------
> net/ipv4/tcp_memcontrol.c | 4 ++--
> 3 files changed, 12 insertions(+), 12 deletions(-)
>
> diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
> index a8df46c..9a19590 100644
> --- a/include/linux/memcontrol.h
> +++ b/include/linux/memcontrol.h
> @@ -704,8 +704,8 @@ static inline void mem_cgroup_wb_stats(struct bdi_writeback *wb,
>
> #ifdef CONFIG_INET
> struct sock;
> -extern struct static_key memcg_sockets_enabled_key;
> -#define mem_cgroup_sockets_enabled static_key_false(&memcg_sockets_enabled_key)
> +extern struct static_key_false memcg_sockets_enabled_key;
> +#define mem_cgroup_sockets_enabled static_branch_unlikely(&memcg_sockets_enabled_key)
> void sock_update_memcg(struct sock *sk);
> void sock_release_memcg(struct sock *sk);
> bool mem_cgroup_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages);
> @@ -727,7 +727,7 @@ static inline bool mem_cgroup_under_socket_pressure(struct mem_cgroup *memcg)
> #endif /* CONFIG_INET */
>
> #ifdef CONFIG_MEMCG_KMEM
> -extern struct static_key memcg_kmem_enabled_key;
> +extern struct static_key_false memcg_kmem_enabled_key;
>
> extern int memcg_nr_cache_ids;
> void memcg_get_cache_ids(void);
> @@ -743,7 +743,7 @@ void memcg_put_cache_ids(void);
>
> static inline bool memcg_kmem_enabled(void)
> {
> - return static_key_false(&memcg_kmem_enabled_key);
> + return static_branch_unlikely(&memcg_kmem_enabled_key);
> }
>
> static inline bool memcg_kmem_is_active(struct mem_cgroup *memcg)
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index a0da91f..5fe45d68 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -346,7 +346,7 @@ void memcg_put_cache_ids(void)
> * conditional to this static branch, we'll have to allow modules that does
> * kmem_cache_alloc and the such to see this symbol as well
> */
> -struct static_key memcg_kmem_enabled_key;
> +DEFINE_STATIC_KEY_FALSE(memcg_kmem_enabled_key);
> EXPORT_SYMBOL(memcg_kmem_enabled_key);
>
> #endif /* CONFIG_MEMCG_KMEM */
> @@ -2883,7 +2883,7 @@ static int memcg_activate_kmem(struct mem_cgroup *memcg,
> err = page_counter_limit(&memcg->kmem, nr_pages);
> VM_BUG_ON(err);
>
> - static_key_slow_inc(&memcg_kmem_enabled_key);
> + static_branch_inc(&memcg_kmem_enabled_key);
> /*
> * A memory cgroup is considered kmem-active as soon as it gets
> * kmemcg_id. Setting the id after enabling static branching will
> @@ -3622,7 +3622,7 @@ static void memcg_destroy_kmem(struct mem_cgroup *memcg)
> {
> if (memcg->kmem_acct_activated) {
> memcg_destroy_kmem_caches(memcg);
> - static_key_slow_dec(&memcg_kmem_enabled_key);
> + static_branch_dec(&memcg_kmem_enabled_key);
> WARN_ON(page_counter_read(&memcg->kmem));
> }
> tcp_destroy_cgroup(memcg);
> @@ -4258,7 +4258,7 @@ mem_cgroup_css_online(struct cgroup_subsys_state *css)
>
> #ifdef CONFIG_INET
> if (cgroup_subsys_on_dfl(memory_cgrp_subsys) && !cgroup_memory_nosocket)
> - static_key_slow_inc(&memcg_sockets_enabled_key);
> + static_branch_inc(&memcg_sockets_enabled_key);
> #endif
>
> /*
> @@ -4302,7 +4302,7 @@ static void mem_cgroup_css_free(struct cgroup_subsys_state *css)
> memcg_destroy_kmem(memcg);
> #ifdef CONFIG_INET
> if (cgroup_subsys_on_dfl(memory_cgrp_subsys) && !cgroup_memory_nosocket)
> - static_key_slow_dec(&memcg_sockets_enabled_key);
> + static_branch_dec(&memcg_sockets_enabled_key);
> #endif
> __mem_cgroup_free(memcg);
> }
> @@ -5494,7 +5494,7 @@ void mem_cgroup_replace_page(struct page *oldpage, struct page *newpage)
>
> #ifdef CONFIG_INET
>
> -struct static_key memcg_sockets_enabled_key;
> +DEFINE_STATIC_KEY_FALSE(memcg_sockets_enabled_key);
> EXPORT_SYMBOL(memcg_sockets_enabled_key);
>
> void sock_update_memcg(struct sock *sk)
> diff --git a/net/ipv4/tcp_memcontrol.c b/net/ipv4/tcp_memcontrol.c
> index 9a22e2d..18bc7f7 100644
> --- a/net/ipv4/tcp_memcontrol.c
> +++ b/net/ipv4/tcp_memcontrol.c
> @@ -34,7 +34,7 @@ void tcp_destroy_cgroup(struct mem_cgroup *memcg)
> return;
>
> if (memcg->tcp_mem.active)
> - static_key_slow_dec(&memcg_sockets_enabled_key);
> + static_branch_dec(&memcg_sockets_enabled_key);
> }
>
> static int tcp_update_limit(struct mem_cgroup *memcg, unsigned long nr_pages)
> @@ -65,7 +65,7 @@ static int tcp_update_limit(struct mem_cgroup *memcg, unsigned long nr_pages)
> * because when this value change, the code to process it is not
> * patched in yet.
> */
> - static_key_slow_inc(&memcg_sockets_enabled_key);
> + static_branch_inc(&memcg_sockets_enabled_key);
> memcg->tcp_mem.active = true;
> }
>
>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/