From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx167.postini.com [74.125.245.167]) by kanga.kvack.org (Postfix) with SMTP id 7383E6B0148 for ; Thu, 13 Sep 2012 06:07:16 -0400 (EDT) Received: from m2.gw.fujitsu.co.jp (unknown [10.0.50.72]) by fgwmail6.fujitsu.co.jp (Postfix) with ESMTP id 632EC3EE0BC for ; Thu, 13 Sep 2012 19:07:14 +0900 (JST) Received: from smail (m2 [127.0.0.1]) by outgoing.m2.gw.fujitsu.co.jp (Postfix) with ESMTP id 35BCF45DE53 for ; Thu, 13 Sep 2012 19:07:14 +0900 (JST) Received: from s2.gw.fujitsu.co.jp (s2.gw.fujitsu.co.jp [10.0.50.92]) by m2.gw.fujitsu.co.jp (Postfix) with ESMTP id 1A58F45DE4D for ; Thu, 13 Sep 2012 19:07:14 +0900 (JST) Received: from s2.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s2.gw.fujitsu.co.jp (Postfix) with ESMTP id 07F621DB802C for ; Thu, 13 Sep 2012 19:07:14 +0900 (JST) Received: from ml14.s.css.fujitsu.com (ml14.s.css.fujitsu.com [10.240.81.134]) by s2.gw.fujitsu.co.jp (Postfix) with ESMTP id A74B61DB803C for ; Thu, 13 Sep 2012 19:07:13 +0900 (JST) Message-ID: <5051B011.7060905@jp.fujitsu.com> Date: Thu, 13 Sep 2012 19:06:09 +0900 From: Kamezawa Hiroyuki MIME-Version: 1.0 Subject: Re: [PATCH] memory cgroup: update root memory cgroup when node is onlined References: <505187D4.7070404@cn.fujitsu.com> In-Reply-To: <505187D4.7070404@cn.fujitsu.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Wen Congyang Cc: "linux-kernel@vger.kernel.org" , cgroups@vger.kernel.org, linux-mm@kvack.org, Jiang Liu , hannes@cmpxchg.org, mhocko@suse.cz, bsingharora@gmail.com, Andrew Morton , hughd@google.com, paul.gortmaker@windriver.com (2012/09/13 16:14), Wen Congyang wrote: > root_mem_cgroup->info.nodeinfo is initialized when the system boots. > But NODE_DATA(nid) is null if the node is not onlined, so > root_mem_cgroup->info.nodeinfo[nid]->zoneinfo[zone].lruvec.zone contains > an invalid pointer. If we use numactl to bind a program to the node > after onlining the node and its memory, it will cause the kernel > panicked: > > [ 63.413436] BUG: unable to handle kernel NULL pointer dereference at 0000000000000f60 > [ 63.414161] IP: [] __mod_zone_page_state+0x9/0x60 > [ 63.414161] PGD 0 > [ 63.414161] Oops: 0000 [#1] SMP > [ 63.414161] Modules linked in: acpi_memhotplug binfmt_misc dm_mirror dm_region_hash dm_log dm_mod ppdev sg microcode pcspkr virtio_console virtio_balloon snd_intel8x0 snd_ac9 > 7_codec ac97_bus snd_seq snd_seq_device snd_pcm snd_timer snd soundcore snd_page_alloc e1000 i2c_piix4 i2c_core floppy parport_pc parport sr_mod cdrom virtio_blk pata_acpi ata_g > eneric ata_piix libata scsi_mod > [ 63.414161] CPU 2 > [ 63.414161] Pid: 1219, comm: numactl Not tainted 3.6.0-rc5+ #180 Bochs Bochs > ... > [ 63.414161] Process numactl (pid: 1219, threadinfo ffff880039abc000, task ffff8800383c4ce0) > [ 63.414161] Stack: > [ 63.414161] ffff880039abdaf8 ffffffff8117390f ffff880039abdaf8 000000008167c601 > [ 63.414161] ffffffff81174162 ffff88003a480f00 0000000000000001 ffff8800395e0000 > [ 63.414161] ffff88003dbd0e80 0000000000000282 ffff880039abdb48 ffffffff81174181 > [ 63.414161] Call Trace: > [ 63.414161] [] __pagevec_lru_add_fn+0xdf/0x140 > [ 63.414161] [] ? pagevec_lru_move_fn+0x92/0x100 > [ 63.414161] [] pagevec_lru_move_fn+0xb1/0x100 > [ 63.414161] [] ? lru_add_page_tail+0x1b0/0x1b0 > [ 63.414161] [] ? exec_mmap+0x121/0x230 > [ 63.414161] [] __pagevec_lru_add+0x1c/0x30 > [ 63.414161] [] lru_add_drain_cpu+0xa3/0x130 > [ 63.414161] [] lru_add_drain+0x2f/0x40 > [ 63.414161] [] exit_mmap+0x69/0x160 > [ 63.414161] [] ? lock_release_holdtime+0x35/0x1a0 > [ 63.414161] [] mmput+0x77/0x100 > [ 63.414161] [] exec_mmap+0x170/0x230 > [ 63.414161] [] flush_old_exec+0xd2/0x140 > [ 63.414161] [] load_elf_binary+0x32a/0xe70 > [ 63.414161] [] ? trace_hardirqs_off+0xd/0x10 > [ 63.414161] [] ? local_clock+0x6f/0x80 > [ 63.414161] [] ? lock_release_holdtime+0x35/0x1a0 > [ 63.414161] [] ? __lock_release+0x133/0x1a0 > [ 63.414161] [] ? search_binary_handler+0x1a7/0x4a0 > [ 63.414161] [] search_binary_handler+0x1b3/0x4a0 > [ 63.414161] [] ? search_binary_handler+0x54/0x4a0 > [ 63.414161] [] ? set_brk+0xe0/0xe0 > [ 63.414161] [] do_execve_common+0x26f/0x320 > [ 63.414161] [] ? kmem_cache_alloc+0x113/0x220 > [ 63.414161] [] do_execve+0x3a/0x40 > [ 63.414161] [] sys_execve+0x4a/0x80 > [ 63.414161] [] stub_execve+0x6c/0xc0 > [ 63.414161] Code: ff 03 00 00 48 c1 e7 0b 48 c1 e2 07 48 29 d7 48 03 3c c5 c0 27 d2 81 e8 a6 fe ff ff c9 c3 0f 1f 40 00 55 48 89 e5 0f 1f 44 00 00 <48> 8b 4f 60 89 f6 48 8d 44 31 40 65 44 8a 40 02 45 0f be c0 41 > > The reason is that we don't update root_mem_cgroup->info.nodeinfo[nid]->zoneinfo[zone].lruvec.zone > when onlining the node, and we try to access it. > > Signed-off-by: Wen Congyang > Reported-by: Tang Chen Thank you !!! But, I think, all memcg's lruvec should be updated. I guess you'll see panic again if you put tasks under memcg and allocates memory on a new node. Could you dig more ? Thanks, -Kame > --- > include/linux/memcontrol.h | 7 +++++++ > mm/memcontrol.c | 14 ++++++++++++++ > mm/memory_hotplug.c | 2 ++ > 3 files changed, 23 insertions(+), 0 deletions(-) > > diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h > index 8d9489f..87d8b77 100644 > --- a/include/linux/memcontrol.h > +++ b/include/linux/memcontrol.h > @@ -182,6 +182,9 @@ unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order, > unsigned long *total_scanned); > > void mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx); > + > +void update_root_mem_cgroup(int nid); > + > #ifdef CONFIG_TRANSPARENT_HUGEPAGE > void mem_cgroup_split_huge_fixup(struct page *head); > #endif > @@ -374,6 +377,10 @@ static inline void mem_cgroup_replace_page_cache(struct page *oldpage, > struct page *newpage) > { > } > + > +static inline void update_root_mem_cgroup(int nid) > +{ > +} > #endif /* CONFIG_MEMCG */ > > #if !defined(CONFIG_MEMCG) || !defined(CONFIG_DEBUG_VM) > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > index 795e525..c997a46 100644 > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > @@ -3427,6 +3427,20 @@ void mem_cgroup_replace_page_cache(struct page *oldpage, > __mem_cgroup_commit_charge(memcg, newpage, 1, type, true); > } > > +/* NODE_DATA(nid) is changed */ > +void update_root_mem_cgroup(int nid) > +{ > + struct mem_cgroup_per_node *pn; > + struct mem_cgroup_per_zone *mz; > + int zone; > + > + pn = root_mem_cgroup->info.nodeinfo[nid]; > + for (zone = 0; zone < MAX_NR_ZONES; zone++) { > + mz = &pn->zoneinfo[zone]; > + lruvec_init(&mz->lruvec, &NODE_DATA(nid)->node_zones[zone]); > + } > +} > + > #ifdef CONFIG_DEBUG_VM > static struct page_cgroup *lookup_page_cgroup_used(struct page *page) > { > diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c > index 3ad25f9..bf03b02 100644 > --- a/mm/memory_hotplug.c > +++ b/mm/memory_hotplug.c > @@ -555,6 +555,8 @@ static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start) > > /* we can use NODE_DATA(nid) from here */ > > + update_root_mem_cgroup(nid); > + > /* init node's zones as empty zones, we don't have any present pages.*/ > free_area_init_node(nid, zones_size, start_pfn, zholes_size); > > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. 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