From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 84C10238171; Wed, 4 Feb 2026 16:14:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770221661; cv=none; b=gJiMnnslTEgP26W7Y5H3FRZ9tOHLDUOaP4jfbcvsbho52OU+gYqYe5a372KWKA3p3yogsJm4KdhEI77KdPc6SKQIBAMZwiY+4QUswfmaMzvT0r3qbjHOj2s1ArT/oFyOfQOADP+tuPiw0MWW0or9IMdTGgiBN/8Lfjdnem/wrsg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770221661; c=relaxed/simple; bh=fpIWi3ZlUU6GICbdztTffdwV8kcfmInvBOHJZpSmhzI=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=K5WX+SGXJ/H0HfPoexZbVIErhfReeF09LpJ6HK68tucujgCkbL9FICNxpEhKP6ZHE9UdKJFqKQxET8MN+8VaRLO0GjHzuOrs9n42iUZyVUEJHCTHyEIjsw9ucLBmprj5FYP4e3ZvF59zTaocDYYB1Lki3qHnV+l0nS4XXbar9S0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=H1vPGXhU; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="H1vPGXhU" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B0BC7C19423; Wed, 4 Feb 2026 16:14:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1770221661; bh=fpIWi3ZlUU6GICbdztTffdwV8kcfmInvBOHJZpSmhzI=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=H1vPGXhUwV6c5NaktCTjngbifuDhCiF+MY5C9rAm7aQpM5UhZIbsPHjKUaCIe3UbT ZPan+cYjuPFcRTfiQwRp/Dsej0VELkl9kaMOIAbUzkJDkyGz4L2UiwDsU4b36C51v9 MhKrNeaY79muH+KxquiZQbjLHI1Qj3LOb13NqQsfOiWDxqSVlKUPgnxqy6QmZiuULt Vg2X4M5Z2v2caTdEbzzI6mAwcTsbi7IWZPydTFK985L+WavMc0OfHDgPnUmU7HI5dX WOWKlCW/gGBMqBOCbmtqu11Dwr8VTP/CMpea3GpAszgJcoyFcHseGtZXiUIxONMT6U W6EDNps1rC7pg== Message-ID: Date: Wed, 4 Feb 2026 17:14:12 +0100 Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCHv6 02/17] mm: Change the interface of prep_compound_tail() To: Kiryl Shutsemau , Andrew Morton , Muchun Song , David Hildenbrand , Matthew Wilcox , Usama Arif , Frank van der Linden Cc: Oscar Salvador , Mike Rapoport , Vlastimil Babka , Lorenzo Stoakes , Zi Yan , Baoquan He , Michal Hocko , Johannes Weiner , Jonathan Corbet , Huacai Chen , WANG Xuerui , Palmer Dabbelt , Paul Walmsley , Albert Ou , Alexandre Ghiti , kernel-team@meta.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, loongarch@lists.linux.dev, linux-riscv@lists.infradead.org References: <20260202155634.650837-1-kas@kernel.org> <20260202155634.650837-3-kas@kernel.org> From: "David Hildenbrand (arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 2/2/26 16:56, Kiryl Shutsemau wrote: > Instead of passing down the head page and tail page index, pass the tail > and head pages directly, as well as the order of the compound page. > > This is a preparation for changing how the head position is encoded in > the tail page. > > Signed-off-by: Kiryl Shutsemau > Reviewed-by: Muchun Song > Reviewed-by: Zi Yan > --- > include/linux/page-flags.h | 4 +++- > mm/hugetlb.c | 8 +++++--- > mm/internal.h | 12 ++++++------ > mm/mm_init.c | 2 +- > mm/page_alloc.c | 2 +- > 5 files changed, 16 insertions(+), 12 deletions(-) > > diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h > index f7a0e4af0c73..8a3694369e15 100644 > --- a/include/linux/page-flags.h > +++ b/include/linux/page-flags.h > @@ -865,7 +865,9 @@ static inline bool folio_test_large(const struct folio *folio) > return folio_test_head(folio); > } > > -static __always_inline void set_compound_head(struct page *page, struct page *head) > +static __always_inline void set_compound_head(struct page *page, > + const struct page *head, > + unsigned int order) Two tab indents please on second+ parameter list whenever you touch code. > { > WRITE_ONCE(page->compound_head, (unsigned long)head + 1); > } > diff --git a/mm/hugetlb.c b/mm/hugetlb.c > index 6e855a32de3d..54ba7cd05a86 100644 [...] > diff --git a/mm/internal.h b/mm/internal.h > index d67e8bb75734..037ddcda25ff 100644 > --- a/mm/internal.h > +++ b/mm/internal.h > @@ -879,13 +879,13 @@ static inline void prep_compound_head(struct page *page, unsigned int order) > INIT_LIST_HEAD(&folio->_deferred_list); > } > > -static inline void prep_compound_tail(struct page *head, int tail_idx) > +static inline void prep_compound_tail(struct page *tail, Just wondering whether we should call this "struct page *page" for consistency with set_compound_head(). Or alternatively, call it also "tail" in set_compound_head(). > + const struct page *head, > + unsigned int order) Two tab indent, then this fits into two lines in total. > { > - struct page *p = head + tail_idx; > - > - p->mapping = TAIL_MAPPING; > - set_compound_head(p, head); > - set_page_private(p, 0); > + tail->mapping = TAIL_MAPPING; > + set_compound_head(tail, head, order); > + set_page_private(tail, 0); > } Only nits, in general LGTM Acked-by: David Hildenbrand (arm) -- Cheers, David