From: "David Hildenbrand (Arm)" <david@kernel.org>
To: "Lorenzo Stoakes (ARM)" <ljs@kernel.org>, Zi Yan <ziy@nvidia.com>,
Baolin Wang <baolin.wang@linux.alibaba.com>,
"Liam R. Howlett" <liam@infradead.org>,
Nico Pache <nico.pache@linux.dev>,
Ryan Roberts <ryan.roberts@arm.com>, Dev Jain <dev.jain@arm.com>,
Barry Song <baohua@kernel.org>, Lance Yang <lance.yang@linux.dev>,
Usama Arif <usama.arif@linux.dev>,
Kiryl Shutsemau <kas@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>, Will Deacon <will@kernel.org>,
Boqun Feng <boqun@kernel.org>, Waiman Long <longman@redhat.com>,
Suren Baghdasaryan <surenb@google.com>,
Vlastimil Babka <vbabka@kernel.org>,
Shakeel Butt <shakeel.butt@linux.dev>,
Yonghong Song <yonghong.song@linux.dev>,
Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andrii@kernel.org>,
Eduard Zingerman <eddyz87@gmail.com>,
Kumar Kartikeya Dwivedi <memxor@gmail.com>,
Martin KaFai Lau <martin.lau@linux.dev>,
Song Liu <song@kernel.org>, Jiri Olsa <jolsa@kernel.org>,
Emil Tsalapatis <emil@etsalapatis.com>,
Ihor Solodrai <ihor.solodrai@linux.dev>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, bpf@vger.kernel.org
Subject: Re: [PATCH 1/5] Revert "mm/khugepaged: remove definition of struct khugepaged_mm_slot"
Date: Thu, 5 Nov 2026 11:17:49 +0100 [thread overview]
Message-ID: <e58309a5-1a5c-4c34-9c28-d1794400616f@kernel.org> (raw)
In-Reply-To: <20261103-khugepaged-latency-fix-v1-1-a07ab16ac860@kernel.org>
On 11/3/26 09:27, Lorenzo Stoakes (ARM) wrote:
> This partially reverts commit b4c9ffb54b32 ("mm/khugepaged: remove
> definition of struct khugepaged_mm_slot"), as a subsequent commit needs to
> resurrect this type to store additional data alongside the mm_slot.
>
> The stated intent of the commit was to address a NULL check in
> __khugepaged_exit():
>
> mm_slot = mm_slot_entry(slot, struct khugepaged_mm_slot, slot);
>
> slot can be NULL and mm_slot_entry() is an alias for container_of(), so
> this is container_of() a NULL value.
>
> This was benign as there was only 1 field in khugepaged_mm_slot (offsetting
> NULL at 0 results in NULL), however it was right to fix this, so retain the
> fix.
>
> It also unwrapped KMEM_CACHE() in khugepaged_init(). This was a mistake,
> and was itself reverted in commit c14bdcc9f274 ("mm/khugepaged: use
> KMEM_CACHE()"). Therefore, retain the KMEM_CACHE() form in this revert.
>
> Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
> ---
LGTM
Reviewed-by: David Hildenbrand (Arm) <david@kernel.org>
--
Cheers,
David
next prev parent reply other threads:[~2026-11-05 10:17 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-11-03 8:27 [PATCH 0/5] mm/khugepaged: bound mmap_lock hold time when walking an mm's VMAs Lorenzo Stoakes (ARM)
2026-11-03 8:27 ` [PATCH 1/5] Revert "mm/khugepaged: remove definition of struct khugepaged_mm_slot" Lorenzo Stoakes (ARM)
2026-11-04 7:46 ` Lance Yang
2026-11-05 10:17 ` David Hildenbrand (Arm) [this message]
2026-11-03 8:27 ` [PATCH 2/5] mm/khugepaged: scan mm's more efficiently under mmap_lock contention Lorenzo Stoakes (ARM)
2026-11-04 8:43 ` Lance Yang
2026-11-05 10:23 ` David Hildenbrand (Arm)
2026-11-05 14:01 ` Lorenzo Stoakes (ARM)
2026-11-03 8:27 ` [PATCH 3/5] locking/rwsem: add down_read[_killable]_nosteal() Lorenzo Stoakes (ARM)
2026-11-03 11:51 ` Peter Zijlstra
2026-11-03 12:24 ` Lorenzo Stoakes (ARM)
2026-11-05 10:25 ` David Hildenbrand (Arm)
2026-11-05 10:29 ` Lorenzo Stoakes (ARM)
2026-11-03 8:27 ` [PATCH 4/5] mm: add and use mmap_read_lock[_killable]_nosteal() on contention Lorenzo Stoakes (ARM)
2026-11-05 10:16 ` David Hildenbrand (Arm)
2026-11-05 14:02 ` Lorenzo Stoakes (ARM)
2026-11-03 8:27 ` [PATCH 5/5] mm/khugepaged: drop/reacquire mmap read lock if skipped enough VMAs Lorenzo Stoakes (ARM)
2026-11-05 10:28 ` David Hildenbrand (Arm)
2026-11-05 14:46 ` Lorenzo Stoakes (ARM)
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