From: David Hildenbrand <david@redhat.com>
To: "Kirill A. Shutemov" <kirill@shutemov.name>, g@box.shutemov.name
Cc: Jann Horn <jannh@google.com>,
Andrew Morton <akpm@linux-foundation.org>,
linux-mm@kvack.org,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
Zach O'Keefe <zokeefe@google.com>,
linux-kernel@vger.kernel.org, Yang Shi <shy828301@gmail.com>
Subject: Re: [PATCH] mm/khugepaged: Fix ->anon_vma race
Date: Tue, 24 Jan 2023 11:19:02 +0100 [thread overview]
Message-ID: <4cb68043-1c06-6589-b83e-74847a06f457@redhat.com> (raw)
In-Reply-To: <20230124005102.ow33h7tfmj5eqyr3@box.shutemov.name>
On 24.01.23 01:51, Kirill A. Shutemov wrote:
> On Mon, Jan 23, 2023 at 12:07:05PM +0100, David Hildenbrand wrote:
>>>> commit bedf03416913d88c796288f9dca109a53608c745
>>>> Author: Yang Shi <shy828301@gmail.com>
>>>> Date: Wed Sep 7 11:01:44 2022 -0700
>>>>
>>>> powerpc/64s/radix: don't need to broadcast IPI for radix pmd collapse flush
>>>> The IPI broadcast is used to serialize against fast-GUP, but fast-GUP will
>>>> move to use RCU instead of disabling local interrupts in fast-GUP. Using
>>>> an IPI is the old-styled way of serializing against fast-GUP although it
>>>> still works as expected now.
>>>> And fast-GUP now fixed the potential race with THP collapse by checking
>>>> whether PMD is changed or not. So IPI broadcast in radix pmd collapse
>>>> flush is not necessary anymore. But it is still needed for hash TLB.
>>>
>>> Okay. But I think tlb_remove_table_sync_one() belongs inside
>>> pmdp_collapse_flush(). Collapsing pmd table into huge page without
>>> serialization is a bug. They should not be separate.
>>
>> Agreed. But I wonder if it should be moved into a generic
>> pmdp_collapse_flush(), that calls an arch specific __pmdp_collapse_flush().
>
> Um? There's no __pmdp_collapse_flush().
Did I imply that there is already one? ;)
--
Thanks,
David / dhildenb
next prev parent reply other threads:[~2023-01-24 10:19 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-11 13:33 [PATCH] mm/khugepaged: Fix ->anon_vma race Jann Horn
2023-01-12 1:06 ` Yang Shi
2023-01-13 19:36 ` Jann Horn
2023-01-12 8:56 ` Kirill A. Shutemov
2023-01-12 18:12 ` Yang Shi
2023-01-13 0:10 ` Kirill A. Shutemov
2023-01-13 3:22 ` Yang Shi
2023-01-13 19:28 ` Jann Horn
2023-01-15 19:06 ` Kirill A. Shutemov
2023-01-16 12:06 ` Jann Horn
2023-01-16 12:34 ` Kirill A. Shutemov
2023-01-16 12:54 ` Jann Horn
2023-01-16 13:07 ` David Hildenbrand
2023-01-16 13:47 ` Kirill A. Shutemov
2023-01-23 11:07 ` David Hildenbrand
2023-01-24 0:51 ` Kirill A. Shutemov
2023-01-24 10:19 ` David Hildenbrand [this message]
2023-01-17 18:57 ` Yang Shi
2023-01-17 19:12 ` Jann Horn
2023-01-17 22:55 ` Andrew Morton
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=4cb68043-1c06-6589-b83e-74847a06f457@redhat.com \
--to=david@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=g@box.shutemov.name \
--cc=jannh@google.com \
--cc=kirill.shutemov@linux.intel.com \
--cc=kirill@shutemov.name \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=shy828301@gmail.com \
--cc=zokeefe@google.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;
as well as URLs for NNTP newsgroup(s).