From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mta1.migadu.com (out-85.mta1.migadu.com [95.215.58.85]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D8E9E37A839 for ; Wed, 19 Aug 2026 09:52:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.85 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787133125; cv=none; b=neDoawgIjoXdeCsU1ZTydH+xegY6yNPiAk1Fv6FVWGiFptX3oSWEYCQpSIpW3ouh2DNWmd3YQvgdCvb3d9GT5dg68X26kkNXlDxhKmg0nlHx9y7r8cQcKEoIytCYHis370RPs6AxHiHuzTaBA9X3g1U/FZ3Nv3zouBtAisovt9g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787133125; c=relaxed/simple; bh=CI9/mKbXLgZPePj0PuaizCdrPnCvZfojfp0mQaycTFk=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=M5dX91/a3QVCkMAYrPPngSpkQbm2F4FPXJhgNh+iDvakBaXcSTqFwUVo5xmgabmOhJCvFTgHy1g9uLd3Tm3T4LRMA+BwLnk0Iu0j5MYuo0+rpW+myis54myYcH8a1x+nXa8JxIVPK4qGxVcFM4GmQTcNPbc8TvBgmetU+vtRBY0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=kOec0YPi; arc=none smtp.client-ip=95.215.58.85 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="kOec0YPi" X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=CI9/mKbXLgZPePj0PuaizCdrPnCvZfojfp0mQaycTFk=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1787133121; v=1; x=1787737921; b=kOec0YPipAkj7WauptHufqCdUxwPl6wJMUULr6yGceNdM51kLlXK8Ia4h3ocn1sMRu+vFyON JZZkhC6d4vhgTi50pxKi+4FfHqqsCvM4z6eKHysRPzTMCh769FTEfu4amAnQLzWesLF7CvOBapd 0UiWE7vS/OKWNMnLIzsaLX8c= X-Envelope-To: linux-kernel@vger.kernel.org Received: from localhost.localdomain (223.70.159.239) by smtp.migadu.com with ESMTPS id 26f8142df68d5de4; Wed, 19 Aug 2026 09:52:01 +0000 X-Migadu-Flow: FLOW_OUT From: Hongfu Li To: akpm@linux-foundation.org, david@kernel.org, ljs@kernel.org, liam@infradead.org, vbabka@kernel.org, rppt@kernel.org, surenb@google.com, mhocko@suse.com Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, hongfu.li@linux.dev, Hongfu Li , Anshuman Khandual Subject: [PATCH v5] mm: Use a folio in the softleaf_is_device_private path Date: Wed, 19 Aug 2026 17:51:43 +0800 Message-ID: <20260819095144.45660-1-hongfu.li@linux.dev> X-Mailer: git-send-email 2.54.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Hongfu Li Use the folio APIs in the device_private migration path of do_swap_page(), replacing four calls to compound_head() with two page_folio() calls. The second one re-fetches the folio from vmf->page after migrate_to_ram(), which might have split the folio. Suggested-by: David Hildenbrand (Arm) Link: https://lore.kernel.org/all/e20678ed-3fa1-4677-a1d7-e2af481e8302@kernel.org/ Signed-off-by: Hongfu Li Acked-by: David Hildenbrand (Arm) Reviewed-by: Lorenzo Stoakes (ARM) Reviewed-by: Anshuman Khandual --- v5: - Re-fetch the folio from vmf->page after migrate_to_ram(), which might have split it - Update commit message - Add Suggested-by and Reviewed-by tags v4: - Drop the do_non_swap_page() extraction (patch 2/2 from v2) - Added Reviewed-by: Lorenzo Stoakes - Link to v2: https://lore.kernel.org/all/20260723030752.16979-1-hongfu.li@linux.dev/ v3: - Please ignore v3. v2: - Drop fault_folio, reuse the existing folio variable instead - Refresh commit messages - Update comment to use "folio" instead of "page" in the device_private path - Add Acked-by: David Hildenbrand - Add patch 2/2 to extract do_non_swap_page() from do_swap_page() - Link to v1: https://lore.kernel.org/all/20260721013347.65698-1-hongfu.li@linux.dev/ --- mm/memory.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/mm/memory.c b/mm/memory.c index c54943302553..c6a9242d1b5b 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -4926,18 +4926,21 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) goto unlock; /* - * Get a page reference while we know the page can't be - * freed. + * Get a folio reference while we know the folio can't + * be freed. */ - if (trylock_page(vmf->page)) { + folio = page_folio(vmf->page); + if (folio_trylock(folio)) { struct dev_pagemap *pgmap; - get_page(vmf->page); + folio_get(folio); pte_unmap_unlock(vmf->pte, vmf->ptl); pgmap = page_pgmap(vmf->page); ret = pgmap->ops->migrate_to_ram(vmf); - unlock_page(vmf->page); - put_page(vmf->page); + /* migrate_to_ram() might have split the folio. */ + folio = page_folio(vmf->page); + folio_unlock(folio); + folio_put(folio); } else { pte_unmap(vmf->pte); softleaf_entry_wait_on_locked(entry, vmf->ptl); -- 2.54.0