From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 481B935CB6D for ; Tue, 16 Jun 2026 13:51:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781617917; cv=none; b=gQVUK6ku5M5S/wT4f2UTkzdzm0+EBaiCk3dY6yj+VrQeTxwVHs3BVph8agCt9O5M/JB6v+7z89bbuW3MA7mL6O3pOYzc1gO/lOqxNX8ZQjQL99+t0Mnia3KRhRGYRzVyWp8JDPWkEcOoWERmYGndRzEnDJmXVTkC+udIIfNaKh4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781617917; c=relaxed/simple; bh=FEn1IUQqxJ/qXD9hp0hXP58/czBETPoSZdsnPkVTJfE=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=YzyIyF3mQFTRrcX6VlkHjDBbCfs0aHQE3/5I9OAcnzm7Mr5nu3sxZlyXpaoIVGyvcZairQYJaKIDWHokYisoeyoFzDXa73/7tDrhBGPNqnXqKj9aBnu+s4NJwIuk9cGLINNrm6KpOgxSctPjNITzO1pXYc/xJceCQ1m3FuVAOso= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=e9vCwaSi; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="e9vCwaSi" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D086A1F000E9; Tue, 16 Jun 2026 13:51:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1781617910; bh=KwHACTTFql24JLhpRs/SKKJ5Pukn1cbDl1znL1oY7TQ=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=e9vCwaSiLr1deDMrhdRjdvNsGwaxmDybQYV61mAAQYH2Iz4GKnnGi+/7PaC59EwzL AOPmq+n2zRtdCNtxN1jdYqwkQUdItRe9rMiwWMAN6IdE6ola59I9f/OxltGVrLqT83 lgBHlT4qsazD2WG/oKqGBXUmda4LozIDkt2dHwVRQXA7bKuPvGovAqIbZBcfIgvSUf HB3kuDMlB3S5bqUriaJ7aWH4RkAl1dNO4N4HeD4faoPUUpN1K13jzDfMGNhEI0vAOE Tk9kSISPcQN8a6tcyAGwoWTvRmHu8KfGijPKNl+1oCBVbF9PhekIE2t4zc9ZbKDWb4 rMteAxo0hgjBA== Message-ID: Date: Tue, 16 Jun 2026 15:51:43 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4 07/12] mm/swapfile: Add batched version of folio_dup_swap To: Dev Jain , akpm@linux-foundation.org, ljs@kernel.org, chrisl@kernel.org, kasong@tencent.com, hughd@google.com, liam@infradead.org Cc: riel@surriel.com, vbabka@kernel.org, harry@kernel.org, jannh@google.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, rppt@kernel.org, surenb@google.com, mhocko@suse.com, qi.zheng@linux.dev, shakeel.butt@linux.dev, baohua@kernel.org, axelrasmussen@google.com, yuanchu@google.com, weixugc@google.com, shikemeng@huaweicloud.com, nphamcs@gmail.com, bhe@redhat.com, youngjun.park@lge.com, baolin.wang@linux.alibaba.com, pfalcato@suse.de, ryan.roberts@arm.com, anshuman.khandual@arm.com References: <20260526063635.61721-1-dev.jain@arm.com> <20260526063635.61721-8-dev.jain@arm.com> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 5/26/26 08:36, Dev Jain wrote: > Add folio_dup_swap_pages to handle a batch of consecutive pages. Note > that folio_dup_swap already can handle a subset of this: nr_pages == 1 and > nr_pages == folio_nr_pages(folio). Generalize this to any nr_pages. > > Currently we have a not-so-nice logic of passing in subpage == NULL if > we mean to exercise the logic on the entire folio, and subpage != NULL if > we want to exercise the logic on only that subpage. Remove this > indirection: the caller invokes folio_dup_swap_pages() if it wants to > operate on a range of pages in the folio (i.e nr_pages may be anything > between 1 till folio_nr_pages()), and invokes folio_dup_swap() if it > wants to operate on the entire folio. > > Signed-off-by: Dev Jain > --- > mm/rmap.c | 2 +- > mm/shmem.c | 2 +- > mm/swap.h | 19 +++++++++++++++++-- > mm/swapfile.c | 14 ++++++-------- > 4 files changed, 25 insertions(+), 12 deletions(-) > > diff --git a/mm/rmap.c b/mm/rmap.c > index ead031361bc61..3065d384cadf8 100644 > --- a/mm/rmap.c > +++ b/mm/rmap.c > @@ -2331,7 +2331,7 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma, > goto finish_unmap; > } > > - if (folio_dup_swap(folio, subpage) < 0) { > + if (folio_dup_swap_pages(folio, subpage, 1) < 0) { > set_pte_at(mm, address, pvmw.pte, pteval); > goto walk_abort; > } > diff --git a/mm/shmem.c b/mm/shmem.c > index bab3529af23c5..5e4f521399847 100644 > --- a/mm/shmem.c > +++ b/mm/shmem.c > @@ -1698,7 +1698,7 @@ int shmem_writeout(struct folio *folio, struct swap_iocb **plug, > spin_unlock(&shmem_swaplist_lock); > } > > - folio_dup_swap(folio, NULL); > + folio_dup_swap(folio); > shmem_delete_from_page_cache(folio, swp_to_radix_entry(folio->swap)); > > BUG_ON(folio_mapped(folio)); > diff --git a/mm/swap.h b/mm/swap.h > index b57547c25ffc9..36c69b2788c77 100644 > --- a/mm/swap.h > +++ b/mm/swap.h > @@ -206,7 +206,8 @@ extern int swap_retry_table_alloc(swp_entry_t entry, gfp_t gfp); > * folio_put_swap(): does the opposite thing of folio_dup_swap(). > */ > int folio_alloc_swap(struct folio *folio); > -int folio_dup_swap(struct folio *folio, struct page *page); > +int folio_dup_swap_pages(struct folio *folio, struct page *page, > + unsigned long nr_pages); Nit: \tab\tab -- Cheers, David