From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f182.google.com (mail-pf1-f182.google.com [209.85.210.182]) (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 7BBE91ADC69 for ; Wed, 25 Jun 2025 17:49:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.182 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750873779; cv=none; b=tBTqlPgBXI5n6dUvTHIAzoNkezg9/Vlut2qYt7zUh1zKWhRRC8VNaRz2hxf8aqYL8+vc1mhu1ynU6jsX4ghbNv+jWy229HzXl5miIT5W8a9ue3jfP0IcbPStWmxBmWCGBqfKxxBDt7hpFBOFf2wucCAKSK5XYiW9P0pZ2sDR+PE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750873779; c=relaxed/simple; bh=hdaQbQzAWC7hOZjbVSYZQ6WivmG3DlnKW6X1M/R7boo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=aK9+xU20LBX6pzSgLJNOgOXp8gY7TfWh8UJHKM63HsiAgHf6SfzwvMy9/KWIL1FCrQNkjVnF2p0aD7gxqX67h3JHgHdW661HHwiaxWQVTbY2Tpx3P7VJgW9sB14nVy7pYg14w+LtwNHpDiqilaOa8WqcMemujLSSxo1aKSZrCgc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=ITI5eHSS; arc=none smtp.client-ip=209.85.210.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="ITI5eHSS" Received: by mail-pf1-f182.google.com with SMTP id d2e1a72fcca58-74931666cbcso250230b3a.0 for ; Wed, 25 Jun 2025 10:49:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1750873778; x=1751478578; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=c1ioaSGcSzaoSqR57at2NFDMA+eF56Ru2c256CsXdIs=; b=ITI5eHSS4J2li/seQOx/iaD0Kd5Rvc1VOfc1w57aDKiExbi0Q38rg1iAC2+4/0Pkht JONUzSOd9sGrX6tNZGiEoZGoJe9d2KrcMKTU1buOkOcNT1W4LZAMhghnKiEOUi/E/taw rzBZIBzM2wfao6Cb+C/fjxMWdUxf1yR+teDM8H0+tFGkqUhR9f89w1UX8zeRpM9eHPsW rUv8gmm9679KjiJIYw8RwsPliC8MdfJeL4jtYCzteOWZOyQ5+uZ1snx4gbCMOpkIXM/b wd8zwko2uehlgXNC0HE6ZPx6UsdlI+H6iFgb5hQMzzWjDqxtM4BbGqpcq8+qkDhG37Gz 28/Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1750873778; x=1751478578; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=c1ioaSGcSzaoSqR57at2NFDMA+eF56Ru2c256CsXdIs=; b=bAgY0kLM7PYDRmSahtGTgaIpYvIuJ/wbgLiCmwsCnbs7stQz4t9e5bqPZGc+Upqkmn 3tA0sY71KZYQDf7yXSu6ceGb7PBzdPwkZdM8gv+aiCmx3wrWRRS0rffnGHIpoqZMlNvX lYntOQane+DcWgqCGcuMmd1EsUyCNNRXwYrNtpN5wfxFwrD0oZmg4YwMUby8LcvVOitO 0P5UA5amrX7dLEv2+8LoGSqUhN/n9bUNhNdWtlBGbUAOapnLlrRu5C9vOyR6kncOSBo8 8WKyMoHQyVtvW6sX/mPyO6ak5ls/bur5IBw+GsL5NL8bkwOyWnVSsiduky9ZraTRH+kV ayfA== X-Gm-Message-State: AOJu0Yxn3FL74VC3+/u+wHB6ZYoJFxGvC6KSVRBylbkHDWFX7tr+v1oS UHdiLXnaHt2xi/gKuK7rd2Q+JVdhhiB01EDkbO+siDKbHRSJpJj4Pix7 X-Gm-Gg: ASbGncvoK/xv+Eya36xPw4bJjFPXh1CJsGVPlIvSXANk140PcH0hJkWdVHTw4vjtABL 1v5Rg3Tv5a9jRtJ96Qv5JTDT72RbWP26+kdN6EVYzcJ2WYswjC6PCF+6CmPm7yebdfMMPAYvBgD 5Fv4951dhyZZg0GI5joXUMg2/pPB7vmcCFokLhDVJ/xgg2/wDuhJyG5hUqU2fG6n1BROpEUM0HC 2mmjnh8qFI9CJVstjS3AXipYGOenidqS+8V9H6BLKIVMUf1gHPO90Sw8PFTuFCzagLULt/GU6de FGrQ23N7MiG3GP1sDcF94Imyr1RilXPKtzjuA+0pPs/UoSu6vWVH6ZpE9OyYUUduOWchbq6j0rn MQwlbQrSqA6zdhwUOpD0SqGGR0JJn6Hg= X-Google-Smtp-Source: AGHT+IFipD4D2odHuNdn/ATlCMR+IXWifKXifixJMQ7PhzMzFi6ZABQLZm7aZko8k9Nhwg8uIoSZQQ== X-Received: by 2002:a05:6a20:7d9a:b0:21f:5361:d7f7 with SMTP id adf61e73a8af0-2207f285b2cmr7515854637.31.1750873777676; Wed, 25 Jun 2025 10:49:37 -0700 (PDT) Received: from fedora.. (c-67-164-59-41.hsd1.ca.comcast.net. [67.164.59.41]) by smtp.googlemail.com with ESMTPSA id d2e1a72fcca58-749b5e23879sm4944869b3a.57.2025.06.25.10.49.36 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 25 Jun 2025 10:49:37 -0700 (PDT) From: "Vishal Moola (Oracle)" To: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, "Matthew Wilcox (Oracle)" , David Hildenbrand , Jordan Rome , Andrew Morton , "Vishal Moola (Oracle)" Subject: [RFC PATCH 1/3] mm/memory.c: convert __copy_remote_vm_str() to folios Date: Wed, 25 Jun 2025 10:48:39 -0700 Message-ID: <20250625174841.1094510-2-vishal.moola@gmail.com> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250625174841.1094510-1-vishal.moola@gmail.com> References: <20250625174841.1094510-1-vishal.moola@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Use kmap_local_folio() instead of kmap_local_page(). Replaces 2 calls to compound_head() from unmap_and_put_page() with one. This prepares us for the removal of unmap_and_put_page(), and helps prepare for the eventual gup folio conversions since this function now supports individual subpages from large folios. Signed-off-by: Vishal Moola (Oracle) --- mm/memory.c | 25 ++++++++++++++++--------- 1 file changed, 16 insertions(+), 9 deletions(-) diff --git a/mm/memory.c b/mm/memory.c index 0f9b32a20e5b..747866060658 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -6820,9 +6820,10 @@ static int __copy_remote_vm_str(struct mm_struct *mm, unsigned long addr, } while (len) { - int bytes, offset, retval; + int bytes, folio_offset, page_offset retval; void *maddr; struct page *page; + struct folio *folio; struct vm_area_struct *vma = NULL; page = get_user_page_vma_remote(mm, addr, gup_flags, &vma); @@ -6837,17 +6838,20 @@ static int __copy_remote_vm_str(struct mm_struct *mm, unsigned long addr, goto out; } + folio = page_folio(page); bytes = len; - offset = addr & (PAGE_SIZE - 1); - if (bytes > PAGE_SIZE - offset) - bytes = PAGE_SIZE - offset; + folio_offset = offset_in_folio(folio, addr); + page_offset = offset_in_page(folio_offset); + + if (bytes > PAGE_SIZE - page_offset) + bytes = PAGE_SIZE - page_offset; - maddr = kmap_local_page(page); - retval = strscpy(buf, maddr + offset, bytes); + maddr = kmap_local_folio(folio, folio_offset); + retval = strscpy(buf, maddr, bytes); if (retval >= 0) { /* Found the end of the string */ buf += retval; - unmap_and_put_page(page, maddr); + folio_release_kmap(folio, maddr); break; } @@ -6859,13 +6863,16 @@ static int __copy_remote_vm_str(struct mm_struct *mm, unsigned long addr, */ if (bytes != len) { addr += bytes - 1; - copy_from_user_page(vma, page, addr, buf, maddr + (PAGE_SIZE - 1), 1); + copy_from_user_page(vma, + folio_page(folio, folio_offset / PAGE_SIZE), + addr, buf, + maddr + (PAGE_SIZE - page_offset - 1), 1); buf += 1; addr += 1; } len -= bytes; - unmap_and_put_page(page, maddr); + folio_release_kmap(folio, maddr); } out: -- 2.49.0