From: Kiryl Shutsemau <kas@kernel.org>
To: Zi Yan <ziy@nvidia.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Muchun Song <muchun.song@linux.dev>,
David Hildenbrand <david@kernel.org>,
Matthew Wilcox <willy@infradead.org>,
Usama Arif <usamaarif642@gmail.com>,
Frank van der Linden <fvdl@google.com>,
Oscar Salvador <osalvador@suse.de>,
Mike Rapoport <rppt@kernel.org>,
Vlastimil Babka <vbabka@suse.cz>,
Lorenzo Stoakes <lorenzo.stoakes@oracle.com>,
Baoquan He <bhe@redhat.com>, Michal Hocko <mhocko@suse.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Jonathan Corbet <corbet@lwn.net>,
kernel-team@meta.com, linux-mm@kvack.org,
linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org
Subject: Re: [PATCHv4 05/14] mm: Rework compound_head() for power-of-2 sizeof(struct page)
Date: Thu, 22 Jan 2026 11:29:43 +0000 [thread overview]
Message-ID: <aXIKBhHd7IbaJkXg@thinkstation> (raw)
In-Reply-To: <EB8941D9-B6E0-41DD-9C44-038D21583E17@nvidia.com>
On Wed, Jan 21, 2026 at 12:12:13PM -0500, Zi Yan wrote:
> > @@ -1244,8 +1244,8 @@ void snapshot_page(struct page_snapshot *ps, const struct page *page)
> > again:
> > memset(&ps->folio_snapshot, 0, sizeof(struct folio));
> > memcpy(&ps->page_snapshot, page, sizeof(*page));
> > - head = ps->page_snapshot.compound_info;
> > - if ((head & 1) == 0) {
> > + info = ps->page_snapshot.compound_info;
> > + if ((info & 1) == 0) {
>
> This could be “if (!(info & 1))” like _compound_head(), right?
Right. But I don't see why it has to change.
--
Kiryl Shutsemau / Kirill A. Shutemov
next prev parent reply other threads:[~2026-01-22 11:29 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-21 16:22 [PATCHv4 00/14] mm: Eliminate fake head pages from vmemmap optimization Kiryl Shutsemau
2026-01-21 16:22 ` [PATCHv4 01/14] mm: Move MAX_FOLIO_ORDER definition to mmzone.h Kiryl Shutsemau
2026-01-21 16:29 ` Zi Yan
2026-01-22 2:24 ` Muchun Song
2026-01-21 16:22 ` [PATCHv4 02/14] mm: Change the interface of prep_compound_tail() Kiryl Shutsemau
2026-01-21 16:32 ` Zi Yan
2026-01-21 16:22 ` [PATCHv4 03/14] mm: Rename the 'compound_head' field in the 'struct page' to 'compound_info' Kiryl Shutsemau
2026-01-21 16:34 ` Zi Yan
2026-01-21 16:22 ` [PATCHv4 04/14] mm: Move set/clear_compound_head() next to compound_head() Kiryl Shutsemau
2026-01-21 16:35 ` Zi Yan
2026-01-21 16:22 ` [PATCHv4 05/14] mm: Rework compound_head() for power-of-2 sizeof(struct page) Kiryl Shutsemau
2026-01-21 17:12 ` Zi Yan
2026-01-22 11:29 ` Kiryl Shutsemau [this message]
2026-01-22 11:52 ` Muchun Song
2026-01-21 16:22 ` [PATCHv4 06/14] mm: Make page_zonenum() use head page Kiryl Shutsemau
2026-01-21 16:28 ` Zi Yan
2026-01-21 16:22 ` [PATCHv4 07/14] mm/sparse: Check memmap alignment for compound_info_has_mask() Kiryl Shutsemau
2026-01-21 17:58 ` Zi Yan
2026-01-22 11:22 ` Kiryl Shutsemau
2026-01-22 3:10 ` Muchun Song
2026-01-22 11:28 ` Kiryl Shutsemau
2026-01-22 11:33 ` Muchun Song
2026-01-22 11:42 ` Muchun Song
2026-01-22 12:42 ` Kiryl Shutsemau
2026-01-22 14:02 ` Muchun Song
2026-01-22 17:59 ` Kiryl Shutsemau
2026-01-23 2:32 ` Muchun Song
2026-01-23 12:07 ` Kiryl Shutsemau
2026-01-21 16:22 ` [PATCHv4 08/14] mm/hugetlb: Refactor code around vmemmap_walk Kiryl Shutsemau
2026-01-22 8:08 ` Muchun Song
2026-01-21 16:22 ` [PATCHv4 09/14] mm/hugetlb: Remove fake head pages Kiryl Shutsemau
2026-01-22 7:00 ` Muchun Song
2026-01-27 14:51 ` Kiryl Shutsemau
2026-01-28 2:43 ` Muchun Song
2026-01-28 12:59 ` Kiryl Shutsemau
2026-01-29 3:04 ` Muchun Song
2026-01-21 16:22 ` [PATCHv4 10/14] mm: Drop fake head checks Kiryl Shutsemau
2026-01-21 18:16 ` Zi Yan
2026-01-22 12:48 ` Kiryl Shutsemau
2026-01-21 16:22 ` [PATCHv4 11/14] hugetlb: Remove VMEMMAP_SYNCHRONIZE_RCU Kiryl Shutsemau
2026-01-21 16:22 ` [PATCHv4 12/14] mm/hugetlb: Remove hugetlb_optimize_vmemmap_key static key Kiryl Shutsemau
2026-01-21 16:22 ` [PATCHv4 13/14] mm: Remove the branch from compound_head() Kiryl Shutsemau
2026-01-21 18:21 ` Zi Yan
2026-01-21 16:22 ` [PATCHv4 14/14] hugetlb: Update vmemmap_dedup.rst Kiryl Shutsemau
2026-01-22 2:22 ` Muchun Song
2026-01-21 18:44 ` [PATCHv4 00/14] mm: Eliminate fake head pages from vmemmap optimization Vlastimil Babka
2026-01-21 20:31 ` Zi Yan
2026-01-22 11:21 ` Kiryl Shutsemau
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