From: 杨欢 <link@vivo.com>
To: Mel Gorman <mgorman@techsingularity.net>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Alexander Lobakin <alobakin@pm.me>,
Vlastimil Babka <vbabka@suse.cz>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
kernel@vivo.com,
syzbot+b07d8440edb5f8988eea@syzkaller.appspotmail.com,
Wang Qing <wangqing@vivo.com>
Subject: Re:Re: Re: [PATCH v2] mm/page_alloc: fix alloc_pages_bulk/set_page_owner panic on irq disabled
Date: Thu, 15 Jul 2021 22:12:52 +0800 (GMT+08:00) [thread overview]
Message-ID: <AIMAoQD-DycrCuBi0i90WqoN.3.1626358372826.Hmail.link@vivo.com> (raw)
In-Reply-To: <20210715140541.GT3809@techsingularity.net>
>> >> Fixes: 0f87d9d30f21 ("mm/page_alloc: add an array-based interface to the bulk page allocator")
>> >> Reported-by: syzbot+b07d8440edb5f8988eea@syzkaller.appspotmail.com
>> >> Suggested-by: Wang Qing <wangqing@vivo.com>
>> >> Signed-off-by: Yang Huan <link@vivo.com>
>> >
>> >https://lore.kernel.org/lkml/20210713152100.10381-2-mgorman@techsingularity.net/
>> >is now part of a series that has being sent to Linus. Hence, the Fixes
>> >part is no longer applicable and the patch will no longer be addresing
>> >an atomic sleep bug. This patch should be treated as an enhancement
>>
>> Hi Mel Gorman, thanks for your reply.
>> I see the fix patch, it fix this bug by abandon alloc bulk feature when page_owner is set.
>> But in my opinion, it can't really fix this bug, it's a circumvention plan.
>
>Yes, it's a circumvention plan for reasons as laid out in the changelog.
>
>> >to allow bulk allocations when PAGE_OWNER is set. For that, it should
>> >include a note on the performance if PAGE_OWNER is used with either NFS
>> >or high-speed networking to justify the additional complexity.
>>
>> My patch just split the prep_new_page page_gfp into alloc_gfp(for alloc bulk is GFP_ATOMIC,
>> for other's no change) and trace page gfp. So, we will not use the error way to get memory.
>> So, I think this will not affect alloc bulk performance when page_owner is on(compare with origin patch) but
>> can really fix this bug rather than evade.
>> And this patch can let alloc bulk feature and page_owner feature work togher
>> So, I will send patch again based on the fix patch.
>
>Your fix should revert the workaround. Also your changelog should note
>that in some cases that PAGE_OWNER information will be lost if the
>GFP_ATOMIC allocation from bulk allocation context fails.
Thanks, I will note that.
>
>--
>Mel Gorman
>SUSE Labs
prev parent reply other threads:[~2021-07-15 14:14 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-12 2:23 Yang Huan
2021-07-15 11:57 ` Mel Gorman
2021-07-15 13:02 ` 杨欢
2021-07-15 14:05 ` Mel Gorman
2021-07-15 14:12 ` 杨欢 [this message]
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=AIMAoQD-DycrCuBi0i90WqoN.3.1626358372826.Hmail.link@vivo.com \
--to=link@vivo.com \
--cc=akpm@linux-foundation.org \
--cc=alobakin@pm.me \
--cc=kernel@vivo.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mgorman@techsingularity.net \
--cc=syzbot+b07d8440edb5f8988eea@syzkaller.appspotmail.com \
--cc=vbabka@suse.cz \
--cc=wangqing@vivo.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox