Messages in this thread | | | Date | Mon, 3 Oct 2011 14:48:15 +0400 | From | Glauber Costa <> | Subject | Re: [PATCH v4 2/8] socket: initial cgroup code. |
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On 10/03/2011 02:47 PM, Kirill A. Shutemov wrote: > On Mon, Oct 03, 2011 at 02:18:37PM +0400, Glauber Costa wrote: >> We aim to control the amount of kernel memory pinned at any >> time by tcp sockets. To lay the foundations for this work, >> this patch adds a pointer to the kmem_cgroup to the socket >> structure. >> >> Signed-off-by: Glauber Costa<glommer@parallels.com> >> CC: David S. Miller<davem@davemloft.net> >> CC: Hiroyouki Kamezawa<kamezawa.hiroyu@jp.fujitsu.com> >> CC: Eric W. Biederman<ebiederm@xmission.com> >> --- >> include/linux/memcontrol.h | 15 +++++++++++++++ >> include/net/sock.h | 2 ++ >> mm/memcontrol.c | 33 +++++++++++++++++++++++++++++++++ >> net/core/sock.c | 3 +++ >> 4 files changed, 53 insertions(+), 0 deletions(-) >> >> diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h >> index 3b535db..2cb9226 100644 >> --- a/include/linux/memcontrol.h >> +++ b/include/linux/memcontrol.h >> @@ -395,5 +395,20 @@ mem_cgroup_print_bad_page(struct page *page) >> } >> #endif >> >> +#ifdef CONFIG_INET >> +struct sock; >> +#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM >> +void sock_update_memcg(struct sock *sk); >> +void sock_release_memcg(struct sock *sk); >> + >> +#else >> +static inline void sock_update_memcg(struct sock *sk) >> +{ >> +} >> +static inline void sock_release_memcg(struct sock *sk) >> +{ >> +} >> +#endif /* CONFIG_CGROUP_MEM_RES_CTLR_KMEM */ >> +#endif /* CONFIG_INET */ >> #endif /* _LINUX_MEMCONTROL_H */ >> >> diff --git a/include/net/sock.h b/include/net/sock.h >> index 8e4062f..afe1467 100644 >> --- a/include/net/sock.h >> +++ b/include/net/sock.h >> @@ -228,6 +228,7 @@ struct sock_common { >> * @sk_security: used by security modules >> * @sk_mark: generic packet mark >> * @sk_classid: this socket's cgroup classid >> + * @sk_cgrp: this socket's kernel memory (kmem) cgroup >> * @sk_write_pending: a write to stream socket waits to start >> * @sk_state_change: callback to indicate change in the state of the sock >> * @sk_data_ready: callback to indicate there is data to be processed >> @@ -339,6 +340,7 @@ struct sock { >> #endif >> __u32 sk_mark; >> u32 sk_classid; >> + struct mem_cgroup *sk_cgrp; >> void (*sk_state_change)(struct sock *sk); >> void (*sk_data_ready)(struct sock *sk, int bytes); >> void (*sk_write_space)(struct sock *sk); >> diff --git a/mm/memcontrol.c b/mm/memcontrol.c >> index 8aaf4ce..08a520e 100644 >> --- a/mm/memcontrol.c >> +++ b/mm/memcontrol.c >> @@ -339,6 +339,39 @@ struct mem_cgroup { >> spinlock_t pcp_counter_lock; >> }; >> >> +/* Writing them here to avoid exposing memcg's inner layout */ >> +#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM >> +#ifdef CONFIG_INET >> +#include<net/sock.h> >> + >> +void sock_update_memcg(struct sock *sk) >> +{ >> + /* right now a socket spends its whole life in the same cgroup */ >> + BUG_ON(sk->sk_cgrp); > > Do we really want to panic in this case? > > What about WARN() + return?
Kirill,
I am keeping this code just to have something workable in between. If you take a look at the last patch, this hunk is going away anyway.
So if you don't oppose it, I'll just keep it to avoid rebasing it.
> Otherwise: Acked-by: Kirill A. Shutemov<kirill@shutemov.name> > >> + >> + rcu_read_lock(); >> + sk->sk_cgrp = mem_cgroup_from_task(current); >> + >> + /* >> + * We don't need to protect against anything task-related, because >> + * we are basically stuck with the sock pointer that won't change, >> + * even if the task that originated the socket changes cgroups. >> + * >> + * What we do have to guarantee, is that the chain leading us to >> + * the top level won't change under our noses. Incrementing the >> + * reference count via cgroup_exclude_rmdir guarantees that. >> + */ >> + cgroup_exclude_rmdir(mem_cgroup_css(sk->sk_cgrp)); >> + rcu_read_unlock(); >> +} >
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