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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B4E52ECAAA1 for ; Mon, 12 Sep 2022 04:57:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229642AbiILE5L (ORCPT ); Mon, 12 Sep 2022 00:57:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54740 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229658AbiILE44 (ORCPT ); Mon, 12 Sep 2022 00:56:56 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 634CD286C8 for ; Sun, 11 Sep 2022 21:56:45 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 25483B80B9F for ; Mon, 12 Sep 2022 04:56:44 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id BB3DAC433D7; Mon, 12 Sep 2022 04:56:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1662958602; bh=7XEbNJXWV99uAkU1++bvWQT/7lCSt9VV2K5eoCrf958=; h=Date:To:From:Subject:From; b=mP8cTgVTdS8wqYUaOywxLjekIhjnl4Sx+KISkJOE6v9Ao0BqKeJ9FmFOTiqGcTbSA MXinnbTQBCUYfrrjt9rG2DYHvzrW5ex9ZVoPsmvjKUDECV8NOF1kFG8pam+j71hPop 3VS3ypaEywePa3VSqugQ9EYig4+7MAoDO6ecW1gc= Date: Sun, 11 Sep 2022 21:56:42 -0700 To: mm-commits@vger.kernel.org, willy@infradead.org, tytso@mit.edu, songmuchun@bytedance.com, slava@dubeyko.com, roman.gushchin@linux.dev, martin.petersen@oracle.com, keescook@chromium.org, kch@nvidia.com, jlayton@kernel.org, ira.weiny@intel.com, damien.lemoal@opensource.wdc.com, brauner@kernel.org, axboe@kernel.dk, arnd@arndb.de, fmdefrancesco@gmail.com, akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-nonmm-stable] hfs-replace-kmap-with-kmap_local_page-in-btreec.patch removed from -mm tree Message-Id: <20220912045642.BB3DAC433D7@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The quilt patch titled Subject: hfs: replace kmap() with kmap_local_page() in btree.c has been removed from the -mm tree. Its filename was hfs-replace-kmap-with-kmap_local_page-in-btreec.patch This patch was dropped because it was merged into the mm-nonmm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: "Fabio M. De Francesco" Subject: hfs: replace kmap() with kmap_local_page() in btree.c Date: Sun, 21 Aug 2022 20:04:00 +0200 kmap() is being deprecated in favor of kmap_local_page(). Two main problems with kmap(): (1) It comes with an overhead as mapping space is restricted and protected by a global lock for synchronization and (2) it also requires global TLB invalidation when the kmap's pool wraps and it might block when the mapping space is fully utilized until a slot becomes available. With kmap_local_page() the mappings are per thread, CPU local, can take page faults, and can be called from any context (including interrupts). It is faster than kmap() in kernels with HIGHMEM enabled. Furthermore, the tasks can be preempted and, when they are scheduled to run again, the kernel virtual addresses are restored and still valid. Since its use in btree.c is safe everywhere, it should be preferred. Therefore, replace kmap() with kmap_local_page() in btree.c. Where possible, use the suited standard helpers (memzero_page(), memcpy_page()) instead of open coding kmap_local_page() plus memset() or memcpy(). Tested in a QEMU/KVM x86_32 VM, 6GB RAM, booting a kernel with HIGHMEM64GB enabled. Link: https://lkml.kernel.org/r/20220821180400.8198-4-fmdefrancesco@gmail.com Signed-off-by: Fabio M. De Francesco Suggested-by: Ira Weiny Reviewed-by: Viacheslav Dubeyko Cc: Arnd Bergmann Cc: Chaitanya Kulkarni Cc: Christian Brauner (Microsoft) Cc: Damien Le Moal Cc: Jeff Layton Cc: Jens Axboe Cc: Kees Cook Cc: Martin K. Petersen Cc: Matthew Wilcox Cc: Muchun Song Cc: Roman Gushchin Cc: Theodore Ts'o Signed-off-by: Andrew Morton --- fs/hfs/btree.c | 30 ++++++++++++++++-------------- 1 file changed, 16 insertions(+), 14 deletions(-) --- a/fs/hfs/btree.c~hfs-replace-kmap-with-kmap_local_page-in-btreec +++ a/fs/hfs/btree.c @@ -80,7 +80,8 @@ struct hfs_btree *hfs_btree_open(struct goto free_inode; /* Load the header */ - head = (struct hfs_btree_header_rec *)(kmap(page) + sizeof(struct hfs_bnode_desc)); + head = (struct hfs_btree_header_rec *)(kmap_local_page(page) + + sizeof(struct hfs_bnode_desc)); tree->root = be32_to_cpu(head->root); tree->leaf_count = be32_to_cpu(head->leaf_count); tree->leaf_head = be32_to_cpu(head->leaf_head); @@ -119,12 +120,12 @@ struct hfs_btree *hfs_btree_open(struct tree->node_size_shift = ffs(size) - 1; tree->pages_per_bnode = (tree->node_size + PAGE_SIZE - 1) >> PAGE_SHIFT; - kunmap(page); + kunmap_local(head); put_page(page); return tree; fail_page: - kunmap(page); + kunmap_local(head); put_page(page); free_inode: tree->inode->i_mapping->a_ops = &hfs_aops; @@ -170,7 +171,8 @@ void hfs_btree_write(struct hfs_btree *t return; /* Load the header */ page = node->page[0]; - head = (struct hfs_btree_header_rec *)(kmap(page) + sizeof(struct hfs_bnode_desc)); + head = (struct hfs_btree_header_rec *)(kmap_local_page(page) + + sizeof(struct hfs_bnode_desc)); head->root = cpu_to_be32(tree->root); head->leaf_count = cpu_to_be32(tree->leaf_count); @@ -181,7 +183,7 @@ void hfs_btree_write(struct hfs_btree *t head->attributes = cpu_to_be32(tree->attributes); head->depth = cpu_to_be16(tree->depth); - kunmap(page); + kunmap_local(head); set_page_dirty(page); hfs_bnode_put(node); } @@ -269,7 +271,7 @@ struct hfs_bnode *hfs_bmap_alloc(struct off += node->page_offset; pagep = node->page + (off >> PAGE_SHIFT); - data = kmap(*pagep); + data = kmap_local_page(*pagep); off &= ~PAGE_MASK; idx = 0; @@ -282,7 +284,7 @@ struct hfs_bnode *hfs_bmap_alloc(struct idx += i; data[off] |= m; set_page_dirty(*pagep); - kunmap(*pagep); + kunmap_local(data); tree->free_nodes--; mark_inode_dirty(tree->inode); hfs_bnode_put(node); @@ -291,14 +293,14 @@ struct hfs_bnode *hfs_bmap_alloc(struct } } if (++off >= PAGE_SIZE) { - kunmap(*pagep); - data = kmap(*++pagep); + kunmap_local(data); + data = kmap_local_page(*++pagep); off = 0; } idx += 8; len--; } - kunmap(*pagep); + kunmap_local(data); nidx = node->next; if (!nidx) { printk(KERN_DEBUG "create new bmap node...\n"); @@ -314,7 +316,7 @@ struct hfs_bnode *hfs_bmap_alloc(struct off = off16; off += node->page_offset; pagep = node->page + (off >> PAGE_SHIFT); - data = kmap(*pagep); + data = kmap_local_page(*pagep); off &= ~PAGE_MASK; } } @@ -361,20 +363,20 @@ void hfs_bmap_free(struct hfs_bnode *nod } off += node->page_offset + nidx / 8; page = node->page[off >> PAGE_SHIFT]; - data = kmap(page); + data = kmap_local_page(page); off &= ~PAGE_MASK; m = 1 << (~nidx & 7); byte = data[off]; if (!(byte & m)) { pr_crit("trying to free free bnode %u(%d)\n", node->this, node->type); - kunmap(page); + kunmap_local(data); hfs_bnode_put(node); return; } data[off] = byte & ~m; set_page_dirty(page); - kunmap(page); + kunmap_local(data); hfs_bnode_put(node); tree->free_nodes++; mark_inode_dirty(tree->inode); _ Patches currently in -mm which might be from fmdefrancesco@gmail.com are