From: David Hildenbrand <david@redhat.com>
To: Michal Hocko <mhocko@suse.com>
Cc: Alexey Makhalov <amakhalov@vmware.com>,
Dennis Zhou <dennis@kernel.org>,
Eric Dumazet <eric.dumazet@gmail.com>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
Andrew Morton <akpm@linux-foundation.org>,
Oscar Salvador <osalvador@suse.de>, Tejun Heo <tj@kernel.org>,
Christoph Lameter <cl@linux.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"stable@vger.kernel.org" <stable@vger.kernel.org>
Subject: Re: [PATCH v3] mm: fix panic in __alloc_pages
Date: Tue, 7 Dec 2021 16:34:30 +0100 [thread overview]
Message-ID: <b7deaf90-8c3c-c22a-b8dc-e6d98bc93ae6@redhat.com> (raw)
In-Reply-To: <Ya992YvnZ3e3G6h0@dhcp22.suse.cz>
On 07.12.21 16:29, Michal Hocko wrote:
> On Tue 07-12-21 16:09:39, David Hildenbrand wrote:
>> On 07.12.21 14:23, Michal Hocko wrote:
>>> On Tue 07-12-21 13:28:31, David Hildenbrand wrote:
>>> [...]
>>>> But maybe I am missing something important regarding online vs. offline
>>>> nodes that your patch changes?
>>>
>>> I am relying on alloc_node_data setting the node online. But if we are
>>> to change the call to arch_alloc_node_data then the patch needs to be
>>> more involved. Here is what I have right now. If this happens to be the
>>> right way then there is some additional work to sync up with the hotplug
>>> code.
>>>
>>> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
>>> index c5952749ad40..a296e934ad2f 100644
>>> --- a/mm/page_alloc.c
>>> +++ b/mm/page_alloc.c
>>> @@ -8032,8 +8032,23 @@ void __init free_area_init(unsigned long *max_zone_pfn)
>>> /* Initialise every node */
>>> mminit_verify_pageflags_layout();
>>> setup_nr_node_ids();
>>> - for_each_online_node(nid) {
>>> - pg_data_t *pgdat = NODE_DATA(nid);
>>> + for_each_node(nid) {
>>> + pg_data_t *pgdat;
>>> +
>>> + if (!node_online(nid)) {
>>> + pr_warn("Node %d uninitialized by the platform. Please report with memory map.\n", nid);
>>> + pgdat = arch_alloc_nodedata(nid);
>>> + pgdat->per_cpu_nodestats = alloc_percpu(struct per_cpu_nodestat);
>>> + arch_refresh_nodedata(nid, pgdat);
>>> + node_set_online(nid);
>>
>> Setting all possible nodes online might result in quite some QE noice,
>> because all these nodes will then be visible in the sysfs and
>> try_offline_nodes() is essentially for the trash.
>
> I am not sure I follow. I believe sysfs will not get populate because I
> do not call register_one_node.
arch/x86/kernel/topology.c:topology_init()
for_each_online_node(i)
register_one_node(i);
>
> You are right that try_offline_nodes will be reduce which is good imho.
> More changes will be possible (hopefully to drop some ugly code) on top
> of this change (or any other that achieves that there are no NULL pgdat
> for possible nodes).
>
No to exposing actually offline nodes to user space via sysfs.
Let's concentrate on preallocating the pgdat and fixing the issue at
hand. One step at a time please.
>> I agree to prealloc the pgdat, I don't think we should actually set the
>> nodes online. Node onlining/offlining should be done when we do have
>> actual CPUs/memory populated.
>
> If we keep the offline/online node state notion we are not solving an
> important aspect of the problem - confusing api.
I don't think it's that confusing. Just like we do have online and
offline CPUs. Or online and offline memory blocks. Similarly, a node is
either online or offline.
--
Thanks,
David / dhildenb
next prev parent reply other threads:[~2021-12-07 15:34 UTC|newest]
Thread overview: 98+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-01 20:13 [PATCH] mm: fix panic in __alloc_pages Alexey Makhalov
2021-11-01 20:38 ` Matthew Wilcox
2021-11-02 7:47 ` Michal Hocko
2021-11-02 8:12 ` David Hildenbrand
2021-11-02 8:48 ` Alexey Makhalov
2021-11-02 9:04 ` Michal Hocko
2021-11-02 9:24 ` David Hildenbrand
2021-11-02 10:34 ` Alexey Makhalov
2021-11-02 11:00 ` David Hildenbrand
2021-11-02 11:44 ` Michal Hocko
2021-11-02 12:06 ` David Hildenbrand
2021-11-02 12:27 ` Michal Hocko
2021-11-02 12:39 ` David Hildenbrand
2021-11-02 13:25 ` Michal Hocko
2021-11-02 13:41 ` David Hildenbrand
2021-11-02 14:12 ` Michal Hocko
2021-11-02 14:44 ` David Hildenbrand
2021-11-02 13:52 ` Oscar Salvador
2021-11-02 14:35 ` Michal Hocko
2021-11-08 6:12 ` Alexey Makhalov
2021-11-08 6:36 ` [PATCH v2] " Alexey Makhalov
2021-11-08 8:32 ` David Hildenbrand
2021-11-08 20:23 ` [PATCH v3] " Alexey Makhalov
2021-11-09 2:08 ` Eric Dumazet
2021-11-09 7:03 ` David Hildenbrand
2021-11-09 16:55 ` Eric Dumazet
2021-11-09 17:15 ` Michal Hocko
2021-11-09 19:06 ` Dennis Zhou
2021-11-09 19:54 ` Michal Hocko
2021-11-16 1:31 ` Alexey Makhalov
2021-11-16 9:17 ` Michal Hocko
2021-11-16 20:22 ` Alexey Makhalov
2021-11-18 8:35 ` Michal Hocko
2021-12-07 10:54 ` Michal Hocko
2021-12-07 11:08 ` David Hildenbrand
2021-12-07 12:13 ` Michal Hocko
2021-12-07 12:28 ` David Hildenbrand
2021-12-07 13:23 ` Michal Hocko
2021-12-07 15:09 ` David Hildenbrand
2021-12-07 15:29 ` Michal Hocko
2021-12-07 15:34 ` David Hildenbrand [this message]
2021-12-07 15:56 ` Michal Hocko
2021-12-07 16:09 ` David Hildenbrand
2021-12-07 16:27 ` Michal Hocko
2021-12-07 16:36 ` Michal Hocko
2021-12-07 16:40 ` David Hildenbrand
2021-12-08 8:28 ` Michal Hocko
2021-12-07 17:02 ` Alexey Makhalov
2021-12-07 17:13 ` David Hildenbrand
2021-12-07 17:17 ` Alexey Makhalov
2021-12-07 18:03 ` David Hildenbrand
2021-12-08 8:12 ` Michal Hocko
2021-12-08 8:24 ` David Hildenbrand
2021-12-08 8:34 ` Michal Hocko
2021-12-08 8:38 ` David Hildenbrand
2021-12-08 8:04 ` Michal Hocko
2021-12-08 8:19 ` Alexey Makhalov
2021-12-08 8:30 ` Michal Hocko
2021-12-08 8:54 ` Michal Hocko
2021-12-08 8:57 ` Alexey Makhalov
2021-12-08 9:55 ` Michal Hocko
2021-12-09 2:16 ` Alexey Makhalov
2021-12-09 8:46 ` Michal Hocko
2021-12-09 9:28 ` Alexey Makhalov
2021-12-09 9:56 ` Michal Hocko
2021-12-09 10:23 ` Alexey Makhalov
2021-12-09 13:29 ` Michal Hocko
2021-12-09 19:01 ` Alexey Makhalov
2021-12-10 9:11 ` Michal Hocko
2021-12-17 12:53 ` Michal Hocko
2021-12-21 5:46 ` Alexey Makhalov
2021-12-21 9:46 ` Michal Hocko
2021-12-21 20:23 ` Alexey Makhalov
2021-12-22 11:41 ` Michal Hocko
2021-12-09 10:48 ` Michal Hocko
2021-12-13 15:06 ` Michal Hocko
2021-12-13 15:07 ` David Hildenbrand
2021-12-14 8:38 ` Michal Hocko
2021-12-14 10:07 ` [PATCH v2 0/4] mm, memory_hotplug: handle unitialized numa node gracefully Michal Hocko
2021-12-14 10:07 ` [PATCH v2 1/4] mm, memory_hotplug: make arch_alloc_nodedata independent on CONFIG_MEMORY_HOTPLUG Michal Hocko
2021-12-14 10:07 ` [PATCH v2 2/4] mm: handle uninitialized numa nodes gracefully Michal Hocko
2021-12-14 10:33 ` Christoph Lameter
2021-12-14 10:38 ` Michal Hocko
2022-01-14 0:24 ` Wei Yang
2022-01-14 10:01 ` Michal Hocko
2021-12-15 4:47 ` kernel test robot
2021-12-15 10:12 ` Michal Hocko
2021-12-14 10:07 ` [PATCH v2 3/4] mm, memory_hotplug: drop arch_free_nodedata Michal Hocko
2021-12-14 10:07 ` [PATCH v2 4/4] mm, memory_hotplug: reorganize new pgdat initialization Michal Hocko
2021-12-17 14:51 ` [PATCH v2 0/4] mm, memory_hotplug: handle unitialized numa node gracefully David Hildenbrand
2021-12-21 9:51 ` Michal Hocko
2022-01-02 7:14 ` Mike Rapoport
2022-01-10 17:16 ` Michal Hocko
2022-01-10 21:16 ` Rafael Aquini
2022-01-11 8:34 ` Michal Hocko
2021-11-08 10:37 ` [PATCH v2] mm: fix panic in __alloc_pages Michal Hocko
2021-11-02 9:40 ` [PATCH] " Alexey Makhalov
2021-11-02 9:40 ` Michal Hocko
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=b7deaf90-8c3c-c22a-b8dc-e6d98bc93ae6@redhat.com \
--to=david@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=amakhalov@vmware.com \
--cc=cl@linux.com \
--cc=dennis@kernel.org \
--cc=eric.dumazet@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mhocko@suse.com \
--cc=osalvador@suse.de \
--cc=stable@vger.kernel.org \
--cc=tj@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).