From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id B1151FCC9DB for ; Tue, 10 Mar 2026 08:50:17 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 1EFDD6B008C; Tue, 10 Mar 2026 04:50:17 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 1C46F6B0092; Tue, 10 Mar 2026 04:50:17 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0C7166B0093; Tue, 10 Mar 2026 04:50:17 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id EF7C26B008C for ; Tue, 10 Mar 2026 04:50:16 -0400 (EDT) Received: from smtpin27.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 804C388E11 for ; Tue, 10 Mar 2026 08:50:16 +0000 (UTC) X-FDA: 84529531632.27.B2B2FC8 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf06.hostedemail.com (Postfix) with ESMTP id 90C4B18000F for ; Tue, 10 Mar 2026 08:50:14 +0000 (UTC) Authentication-Results: imf06.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=arm.com; spf=pass (imf06.hostedemail.com: domain of dev.jain@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=dev.jain@arm.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1773132614; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=pFtYnp02cguLN7jzQawh5ValF68OK9G0qnxxVk8SPLg=; b=z9wkC4+QKZb6WlxHy7xc1IECrFv7LOf5NlqXg7OPUVJ5p6hQbq6QrSSlBkWrEN0Wki/riW 9EWuBeEeYSzMsaZTUU+y19AejT0inRU7rtGtFKWVgICKMhynD8UcRJ5vmNzUP46o9nV6yK a2LjOkKHaGgLAFpm8klAsTiQOHo3iVM= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1773132614; a=rsa-sha256; cv=none; b=NNtFIMw3yJS5HmxbViZFstETItPu9AeApT3Gwr23nA11GH4V28hAvb7DHswy5BY3TO+hUw xvuwZUgAD53wkhr/t087XZ+ROJB4HputyTjl00fskEyGAqOy6isuCiUPT5pxkHz+yUzBxG rU7v51CwpekMYgOqWuYS5wxHBkR7auc= ARC-Authentication-Results: i=1; imf06.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=arm.com; spf=pass (imf06.hostedemail.com: domain of dev.jain@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=dev.jain@arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 8CB9B169C; Tue, 10 Mar 2026 01:50:07 -0700 (PDT) Received: from [10.164.19.59] (unknown [10.164.19.59]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 02EFD3F7BD; Tue, 10 Mar 2026 01:50:04 -0700 (PDT) Message-ID: <373b96e7-fda3-4ea2-8089-521dba064307@arm.com> Date: Tue, 10 Mar 2026 14:20:02 +0530 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 7/9] mm/swapfile: Make folio_put_swap batchable To: Kairui Song Cc: akpm@linux-foundation.org, axelrasmussen@google.com, yuanchu@google.com, david@kernel.org, hughd@google.com, chrisl@kernel.org, weixugc@google.com, ljs@kernel.org, Liam.Howlett@oracle.com, vbabka@kernel.org, rppt@kernel.org, surenb@google.com, mhocko@suse.com, riel@surriel.com, harry.yoo@oracle.com, jannh@google.com, pfalcato@suse.de, baolin.wang@linux.alibaba.com, shikemeng@huaweicloud.com, nphamcs@gmail.com, bhe@redhat.com, baohua@kernel.org, youngjun.park@lge.com, ziy@nvidia.com, kas@kernel.org, willy@infradead.org, yuzhao@google.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, ryan.roberts@arm.com, anshuman.khandual@arm.com References: <20260310073013.4069309-1-dev.jain@arm.com> <20260310073013.4069309-8-dev.jain@arm.com> Content-Language: en-US From: Dev Jain In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 90C4B18000F X-Stat-Signature: erp4aopktw6jpwgdym4ygjwktxxer9ze X-Rspam-User: X-HE-Tag: 1773132614-532736 X-HE-Meta: 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 VwHkwPBL 4jM4u5yXda8lZRGgFpYLix44dRE/eYzptdcrfGe/El0gzYfGu9Rg0egPWxTWAZuVPHhHn8pZxY90jmBpkaPcOLAjtsDz+vS+rpVLnhx6lpxhqkHNFl0nKAe826iPumbG7amg6gbHO/MPa6QHdBhoKHyxi8O53b8pn1rA1sMepAO0r1zHw6RY3tFpkVSFqfXs7YnXh894PTBKpDSCubs4UGOkpkh7oKK3Mvd4LguNFHzis/r/ZCacGzuatKgZM0f8S9/T3cyhJv2wTYqd3ljndGfGcz2XLcOtHiGmlgVhnlMYWPmUA7XKUcIlKbA== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 10/03/26 1:59 pm, Kairui Song wrote: > On Tue, Mar 10, 2026 at 3:47 PM Dev Jain wrote: >> >> Teach folio_put_swap to handle a batch of consecutive pages. Note that >> folio_put_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, and explicitly pass subpage != NULL, and the number of >> pages required. >> >> Signed-off-by: Dev Jain >> --- >> mm/memory.c | 6 +++--- >> mm/rmap.c | 4 ++-- >> mm/shmem.c | 6 +++--- >> mm/swap.h | 5 +++-- >> mm/swapfile.c | 13 +++++-------- >> 5 files changed, 16 insertions(+), 18 deletions(-) >> >> diff --git a/mm/memory.c b/mm/memory.c >> index 768646c0b3b6a..8249a9b7083ab 100644 >> --- a/mm/memory.c >> +++ b/mm/memory.c >> @@ -5002,7 +5002,7 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) >> if (unlikely(folio != swapcache)) { >> folio_add_new_anon_rmap(folio, vma, address, RMAP_EXCLUSIVE); >> folio_add_lru_vma(folio, vma); >> - folio_put_swap(swapcache, NULL); >> + folio_put_swap(swapcache, folio_page(swapcache, 0), folio_nr_pages(swapcache)); >> } else if (!folio_test_anon(folio)) { >> /* >> * We currently only expect !anon folios that are fully >> @@ -5011,12 +5011,12 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) >> VM_WARN_ON_ONCE_FOLIO(folio_nr_pages(folio) != nr_pages, folio); >> VM_WARN_ON_ONCE_FOLIO(folio_mapped(folio), folio); >> folio_add_new_anon_rmap(folio, vma, address, rmap_flags); >> - folio_put_swap(folio, NULL); >> + folio_put_swap(folio, folio_page(folio, 0), folio_nr_pages(folio)); >> } else { >> VM_WARN_ON_ONCE(nr_pages != 1 && nr_pages != folio_nr_pages(folio)); >> folio_add_anon_rmap_ptes(folio, page, nr_pages, vma, address, >> rmap_flags); >> - folio_put_swap(folio, nr_pages == 1 ? page : NULL); >> + folio_put_swap(folio, page, nr_pages); >> } >> >> VM_BUG_ON(!folio_test_anon(folio) || >> diff --git a/mm/rmap.c b/mm/rmap.c >> index f6d5b187cf09b..42f6b00cced01 100644 >> --- a/mm/rmap.c >> +++ b/mm/rmap.c >> @@ -2293,7 +2293,7 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma, >> * so we'll not check/care. >> */ >> if (arch_unmap_one(mm, vma, address, pteval) < 0) { >> - folio_put_swap(folio, subpage); >> + folio_put_swap(folio, subpage, 1); >> set_pte_at(mm, address, pvmw.pte, pteval); >> goto walk_abort; >> } >> @@ -2301,7 +2301,7 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma, >> /* See folio_try_share_anon_rmap(): clear PTE first. */ >> if (anon_exclusive && >> folio_try_share_anon_rmap_pte(folio, subpage)) { >> - folio_put_swap(folio, subpage); >> + folio_put_swap(folio, subpage, 1); >> set_pte_at(mm, address, pvmw.pte, pteval); >> goto walk_abort; >> } >> diff --git a/mm/shmem.c b/mm/shmem.c >> index 86ee34c9b40b3..d9d216ea28ecb 100644 >> --- a/mm/shmem.c >> +++ b/mm/shmem.c >> @@ -1716,7 +1716,7 @@ int shmem_writeout(struct folio *folio, struct swap_iocb **plug, >> /* Swap entry might be erased by racing shmem_free_swap() */ >> if (!error) { >> shmem_recalc_inode(inode, 0, -nr_pages); >> - folio_put_swap(folio, NULL); >> + folio_put_swap(folio, folio_page(folio, 0), folio_nr_pages(folio)); > > I just realized that we already have a nr_pages variable available > here, maybe you can just use that? > > Feel free to ignore this if it might touch more code. > >> } >> >> /* >> @@ -2196,7 +2196,7 @@ static void shmem_set_folio_swapin_error(struct inode *inode, pgoff_t index, >> >> nr_pages = folio_nr_pages(folio); >> folio_wait_writeback(folio); >> - folio_put_swap(folio, NULL); >> + folio_put_swap(folio, folio_page(folio, 0), folio_nr_pages(folio)); >> swap_cache_del_folio(folio); >> /* >> * Don't treat swapin error folio as alloced. Otherwise inode->i_blocks >> @@ -2426,7 +2426,7 @@ static int shmem_swapin_folio(struct inode *inode, pgoff_t index, >> if (sgp == SGP_WRITE) >> folio_mark_accessed(folio); >> >> - folio_put_swap(folio, NULL); >> + folio_put_swap(folio, folio_page(folio, 0), folio_nr_pages(folio)); > > Same here, nr_pages seems good enough? Yup, thanks for your observation.