public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Andrew Morton <akpm@linux-foundation.org>
To: Luiz Capitulino <luizcap@redhat.com>
Cc: hca@linux.ibm.com, borntraeger@linux.ibm.com,
	joao.m.martins@oracle.com, mike.kravetz@oracle.com,
	linux-kernel@vger.kernel.org, linux-mm@kvack.org,
	linux-s390@vger.kernel.org, gor@linux.ibm.com,
	gerald.schaefer@linux.ibm.com, agordeev@linux.ibm.com,
	osalvador@suse.de, david@redhat.com, aneesh.kumar@kernel.org
Subject: Re: [PATCH v2] s390: fix HugeTLB vmemmap optimization crash
Date: Tue, 28 Oct 2025 14:53:34 -0700	[thread overview]
Message-ID: <20251028145334.5a97211e0e46ca42fe2fa0d0@linux-foundation.org> (raw)
In-Reply-To: <20251028211533.47694-1-luizcap@redhat.com>

On Tue, 28 Oct 2025 17:15:33 -0400 Luiz Capitulino <luizcap@redhat.com> wrote:

> A reproducible crash occurs when enabling HugeTLB vmemmap optimization (HVO)
> on s390. The crash and the proposed fix were worked on an s390 KVM guest
> running on an older hypervisor, as I don't have access to an LPAR. However,
> the same issue should occur on bare-metal.
> 
> Reproducer (it may take a few runs to trigger):
> 
>  # sysctl vm.hugetlb_optimize_vmemmap=1
>  # echo 1 > /proc/sys/vm/nr_hugepages
>  # echo 0 > /proc/sys/vm/nr_hugepages
> 
> ...
> 
> This commit fixes this by implementing flush_tlb_all() on s390 as an
> alias to __tlb_flush_global(). This should cause a flush on all TLB
> entries on all CPUs as expected by the flush_tlb_all() semantics.
> 
> ...
>
>  arch/s390/include/asm/tlbflush.h | 6 +++++-

Thanks, I'll add this to mm.git.  If s390 people prefer to merge it
(or nack it!) then please do so and I'll drop the mm.git copy.


  reply	other threads:[~2025-10-28 21:53 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-10-28 21:15 [PATCH v2] s390: fix HugeTLB vmemmap optimization crash Luiz Capitulino
2025-10-28 21:53 ` Andrew Morton [this message]
2025-10-30 14:59   ` Heiko Carstens
2025-10-29  6:36 ` Alexander Gordeev
2025-10-29  9:57 ` David Hildenbrand
2025-10-29 10:44   ` Heiko Carstens
2025-10-29 12:15     ` David Hildenbrand
2025-10-29 12:49       ` Heiko Carstens
2025-10-30 14:38         ` Gerald Schaefer
2025-10-30 14:54           ` Luiz Capitulino
2025-10-30 14:56             ` Heiko Carstens

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=20251028145334.5a97211e0e46ca42fe2fa0d0@linux-foundation.org \
    --to=akpm@linux-foundation.org \
    --cc=agordeev@linux.ibm.com \
    --cc=aneesh.kumar@kernel.org \
    --cc=borntraeger@linux.ibm.com \
    --cc=david@redhat.com \
    --cc=gerald.schaefer@linux.ibm.com \
    --cc=gor@linux.ibm.com \
    --cc=hca@linux.ibm.com \
    --cc=joao.m.martins@oracle.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=linux-s390@vger.kernel.org \
    --cc=luizcap@redhat.com \
    --cc=mike.kravetz@oracle.com \
    --cc=osalvador@suse.de \
    /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