From: "liupeng (DM)" <liupeng256@huawei.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: <mike.kravetz@oracle.com>, <david@redhat.com>,
<yaozhenguo1@gmail.com>, <baolin.wang@linux.alibaba.com>,
<songmuchun@bytedance.com>, <liuyuntao10@huawei.com>,
<linux-mm@kvack.org>, <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v3 1/4] hugetlb: Fix wrong use of nr_online_nodes
Date: Wed, 13 Apr 2022 14:27:54 +0800 [thread overview]
Message-ID: <692ee24c-a705-0c54-7cad-a9ecf49a8f15@huawei.com> (raw)
In-Reply-To: <20220412214238.84c20437a052458f6967e9fd@linux-foundation.org>
[-- Attachment #1: Type: text/plain, Size: 878 bytes --]
On 2022/4/13 12:42, Andrew Morton wrote:
> On Wed, 13 Apr 2022 03:29:12 +0000 Peng Liu<liupeng256@huawei.com> wrote:
>
>> Certain systems are designed to have sparse/discontiguous nodes. In
>> this case, nr_online_nodes can not be used to walk through numa node.
>> Also, a valid node may be greater than nr_online_nodes.
>>
>> However, in hugetlb, it is assumed that nodes are contiguous. Recheck
>> all the places that use nr_online_nodes, and repair them one by one.
>>
> What are the runtime effects of this shortcoming?
> .
For sparse/discontiguous nodes, the current code may treat a valid node
as invalid, and will fail to allocate all hugepages on a valid node that
"nid >= nr_online_nodes".
As David suggested:
if (tmp >= nr_online_nodes)
goto invalid;
Just imagine node 0 and node 2 are online, and node 1 is offline. Assuming
that "node < 2" is valid is wrong.
[-- Attachment #2: Type: text/html, Size: 1476 bytes --]
next prev parent reply other threads:[~2022-04-13 6:28 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-13 3:29 [PATCH v3 0/4] hugetlb: Fix some incorrect behavior Peng Liu
2022-04-13 3:29 ` [PATCH v3 1/4] hugetlb: Fix wrong use of nr_online_nodes Peng Liu
2022-04-13 4:42 ` Andrew Morton
2022-04-13 6:27 ` liupeng (DM) [this message]
2022-04-13 22:04 ` Andrew Morton
2022-04-14 1:28 ` liupeng (DM)
2022-04-13 6:29 ` Baolin Wang
2022-04-14 23:36 ` Mike Kravetz
2022-04-15 2:09 ` Davidlohr Bueso
2022-04-15 5:41 ` Kefeng Wang
2022-04-15 7:01 ` liupeng (DM)
2022-04-16 1:21 ` Kefeng Wang
2022-04-19 4:40 ` Andrew Morton
2022-04-19 8:54 ` Kefeng Wang
2022-04-16 10:35 ` [PATCH v4] " Peng Liu
2022-04-18 5:53 ` Kefeng Wang
2022-04-19 4:03 ` Andrew Morton
2022-04-19 14:07 ` Kefeng Wang
2022-04-20 6:17 ` liupeng (DM)
2022-04-29 9:32 ` David Hildenbrand
2022-04-13 3:29 ` [PATCH v3 2/4] hugetlb: Fix hugepages_setup when deal with pernode Peng Liu
2022-04-14 23:50 ` Mike Kravetz
2022-04-29 9:30 ` David Hildenbrand
2022-04-13 3:29 ` [PATCH v3 3/4] hugetlb: Fix return value of __setup handlers Peng Liu
2022-04-13 6:39 ` Baolin Wang
2022-04-13 7:55 ` Muchun Song
2022-04-13 8:16 ` liupeng (DM)
2022-04-13 8:21 ` Muchun Song
2022-04-13 8:45 ` Kefeng Wang
2022-04-13 9:01 ` Muchun Song
2022-04-15 0:01 ` Mike Kravetz
2022-04-15 2:24 ` Davidlohr Bueso
2022-04-29 2:43 ` [PATCH v4] mm: Using for_each_online_node and node_online instead of open coding Peng Liu
2022-04-29 3:02 ` Peng Liu
2022-04-29 9:29 ` David Hildenbrand
2022-04-29 9:29 ` David Hildenbrand
2022-04-29 11:44 ` Muchun Song
2022-04-29 11:44 ` Muchun Song
2022-04-13 3:29 ` [PATCH v3 4/4] hugetlb: Clean up hugetlb_cma_reserve Peng Liu
2022-04-13 5:50 ` Muchun Song
2022-04-13 6:41 ` Baolin Wang
2022-04-15 0:03 ` Mike Kravetz
2022-04-15 2:15 ` Davidlohr Bueso
2022-04-15 7:03 ` liupeng (DM)
2022-04-29 9:28 ` David Hildenbrand
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=692ee24c-a705-0c54-7cad-a9ecf49a8f15@huawei.com \
--to=liupeng256@huawei.com \
--cc=akpm@linux-foundation.org \
--cc=baolin.wang@linux.alibaba.com \
--cc=david@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=liuyuntao10@huawei.com \
--cc=mike.kravetz@oracle.com \
--cc=songmuchun@bytedance.com \
--cc=yaozhenguo1@gmail.com \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.