From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx201.postini.com [74.125.245.201]) by kanga.kvack.org (Postfix) with SMTP id 0C04D6B0130 for ; Tue, 26 Jun 2012 05:20:19 -0400 (EDT) Message-ID: <4FE97E31.3010201@parallels.com> Date: Tue, 26 Jun 2012 13:17:37 +0400 From: Glauber Costa MIME-Version: 1.0 Subject: Re: [PATCH 06/11] memcg: kmem controller infrastructure References: <1340633728-12785-1-git-send-email-glommer@parallels.com> <1340633728-12785-7-git-send-email-glommer@parallels.com> In-Reply-To: Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: David Rientjes Cc: cgroups@vger.kernel.org, linux-mm@kvack.org, Andrew Morton , linux-kernel@vger.kernel.org, Frederic Weisbecker , Pekka Enberg , Michal Hocko , Johannes Weiner , Christoph Lameter , devel@openvz.org, kamezawa.hiroyu@jp.fujitsu.com, Tejun Heo , Pekka Enberg On 06/26/2012 01:12 PM, David Rientjes wrote: > On Mon, 25 Jun 2012, Glauber Costa wrote: > >> diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h >> index 83e7ba9..22479eb 100644 >> --- a/include/linux/memcontrol.h >> +++ b/include/linux/memcontrol.h >> @@ -21,6 +21,7 @@ >> #define _LINUX_MEMCONTROL_H >> #include >> #include >> +#include >> >> struct mem_cgroup; >> struct page_cgroup; >> @@ -409,6 +410,12 @@ struct sock; >> #ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM >> void sock_update_memcg(struct sock *sk); >> void sock_release_memcg(struct sock *sk); >> + >> +#define mem_cgroup_kmem_on 1 >> +bool __mem_cgroup_new_kmem_page(gfp_t gfp, void *handle, int order); >> +void __mem_cgroup_commit_kmem_page(struct page *page, void *handle, int order); >> +void __mem_cgroup_free_kmem_page(struct page *page, int order); >> +#define is_kmem_tracked_alloc (gfp & __GFP_KMEMCG) >> #else >> static inline void sock_update_memcg(struct sock *sk) >> { >> @@ -416,6 +423,43 @@ static inline void sock_update_memcg(struct sock *sk) >> static inline void sock_release_memcg(struct sock *sk) >> { >> } >> + >> +#define mem_cgroup_kmem_on 0 >> +#define __mem_cgroup_new_kmem_page(a, b, c) false >> +#define __mem_cgroup_free_kmem_page(a,b ) >> +#define __mem_cgroup_commit_kmem_page(a, b, c) >> +#define is_kmem_tracked_alloc (false) >> #endif /* CONFIG_CGROUP_MEM_RES_CTLR_KMEM */ >> + >> +static __always_inline >> +bool mem_cgroup_new_kmem_page(gfp_t gfp, void *handle, int order) >> +{ >> + if (!mem_cgroup_kmem_on) >> + return true; >> + if (!is_kmem_tracked_alloc) >> + return true; >> + if (!current->mm) >> + return true; >> + if (in_interrupt()) >> + return true; > > You can't test for current->mm in irq context, so you need to check for > in_interrupt() first. > Right, thanks. > Also, what prevents __mem_cgroup_new_kmem_page() > from being called for a kthread that has called use_mm() before > unuse_mm()? Nothing, but I also don't see how to prevent that. At a first glance, it seems fair to me to say that if a kernel thread uses the mm of a process, it poses as this process for any accounting purpose. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org