Messages in this thread | | | Date | Tue, 4 Oct 2011 11:13:50 +0400 | From | Glauber Costa <> | Subject | Re: [PATCH v4 3/8] foundations of per-cgroup memory pressure controlling. |
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On 10/04/2011 04:57 AM, KAMEZAWA Hiroyuki wrote: > On Mon, 3 Oct 2011 14:18:38 +0400 > Glauber Costa<glommer@parallels.com> wrote: > >> This patch converts struct sock fields memory_pressure, >> memory_allocated, sockets_allocated, and sysctl_mem (now prot_mem) >> to function pointers, receiving a struct mem_cgroup parameter. >> >> enter_memory_pressure is kept the same, since all its callers >> have socket a context, and the kmem_cgroup can be derived from >> the socket itself. >> >> To keep things working, the patch convert all users of those fields >> to use acessor functions. >> >> In my benchmarks I didn't see a significant performance difference >> with this patch applied compared to a baseline (around 1 % diff, thus >> inside error margin). >> >> 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> > > A nitpick. > > >> #ifdef CONFIG_INET >> struct sock; >> +struct proto; >> #ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM >> void sock_update_memcg(struct sock *sk); >> void sock_release_memcg(struct sock *sk); >> - >> +void memcg_sock_mem_alloc(struct mem_cgroup *mem, struct proto *prot, >> + int amt, int *parent_failure); >> +void memcg_sock_mem_free(struct mem_cgroup *mem, struct proto *prot, int amt); >> +void memcg_sockets_allocated_dec(struct mem_cgroup *mem, struct proto *prot); >> +void memcg_sockets_allocated_inc(struct mem_cgroup *mem, struct proto *prot); >> #else >> +/* memcontrol includes sockets.h, that includes memcontrol.h ... */ >> +static inline void memcg_sock_mem_alloc(struct mem_cgroup *mem, >> + struct proto *prot, int amt, >> + int *parent_failure) >> +{ >> +} > > In these days, at naming memory cgroup pointers, we use "memcg" instead of > "mem". So, could you use "memcg" for represeinting memory cgroup ? > > >> + >> +void memcg_sock_mem_alloc(struct mem_cgroup *mem, struct proto *prot, >> + int amt, int *parent_failure) >> +{ >> + mem = parent_mem_cgroup(mem); >> + for (; mem != NULL; mem = parent_mem_cgroup(mem)) { >> + long alloc; >> + long *prot_mem = prot->prot_mem(mem); >> + /* >> + * Large nestings are not the common case, and stopping in the >> + * middle would be complicated enough, that we bill it all the >> + * way through the root, and if needed, unbill everything later >> + */ >> + alloc = atomic_long_add_return(amt, >> + prot->memory_allocated(mem)); >> + *parent_failure |= (alloc> prot_mem[2]); >> + } >> +} >> +EXPORT_SYMBOL(memcg_sock_mem_alloc); > > Hmm. why not using res_counter ? for reusing 'unbill' code ? > > Thanks, > -Kame > Well, besides the cost, we'd have atomic_t for !cgroups, and res_counter for cgroups. I think there is value in keeping them the same.
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