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 A76C3ECAAA1 for ; Mon, 12 Sep 2022 04:57:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229631AbiILE5I (ORCPT ); Mon, 12 Sep 2022 00:57:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54588 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229614AbiILE44 (ORCPT ); Mon, 12 Sep 2022 00:56:56 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 787DC286C0 for ; Sun, 11 Sep 2022 21:56:42 -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 dfw.source.kernel.org (Postfix) with ESMTPS id 1396960CFA for ; Mon, 12 Sep 2022 04:56:42 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 63E69C433D6; Mon, 12 Sep 2022 04:56:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1662958601; bh=DRBLUY1y7vQ3fvkC1OJ2DdS0kgveczIzWNJHaiPLh0g=; h=Date:To:From:Subject:From; b=J8VCOfyQLfybVzdmQur8C+IX/x3okYFnXMt0bj99Q48eQYnv3+K2hXpLKHnPXVRu4 zO54NqiiMAq1nEWigT8dG2V4y5M/cG76Uk8t1/hbmSInb78NO216Tp5/w8i/PwjdbL C09uNaaeOj8Xm0WDvVTDD4uhoi4/9Wx2Aw31m5OQ= Date: Sun, 11 Sep 2022 21:56:40 -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-bnodec.patch removed from -mm tree Message-Id: <20220912045641.63E69C433D6@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 bnode.c has been removed from the -mm tree. Its filename was hfs-replace-kmap-with-kmap_local_page-in-bnodec.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 bnode.c Date: Sun, 21 Aug 2022 20:03:59 +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 bnode.c is safe everywhere, it should be preferred. Therefore, replace kmap() with kmap_local_page() in bnode.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/20220821180400.8198-3-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/bnode.c | 32 ++++++++++++-------------------- 1 file changed, 12 insertions(+), 20 deletions(-) --- a/fs/hfs/bnode.c~hfs-replace-kmap-with-kmap_local_page-in-bnodec +++ a/fs/hfs/bnode.c @@ -21,7 +21,6 @@ void hfs_bnode_read(struct hfs_bnode *no int pagenum; int bytes_read; int bytes_to_read; - void *vaddr; off += node->page_offset; pagenum = off >> PAGE_SHIFT; @@ -33,9 +32,7 @@ void hfs_bnode_read(struct hfs_bnode *no page = node->page[pagenum]; bytes_to_read = min_t(int, len - bytes_read, PAGE_SIZE - off); - vaddr = kmap_atomic(page); - memcpy(buf + bytes_read, vaddr + off, bytes_to_read); - kunmap_atomic(vaddr); + memcpy_from_page(buf + bytes_read, page, off, bytes_to_read); pagenum++; off = 0; /* page offset only applies to the first page */ @@ -80,8 +77,7 @@ void hfs_bnode_write(struct hfs_bnode *n off += node->page_offset; page = node->page[0]; - memcpy(kmap(page) + off, buf, len); - kunmap(page); + memcpy_to_page(page, off, buf, len); set_page_dirty(page); } @@ -105,8 +101,7 @@ void hfs_bnode_clear(struct hfs_bnode *n off += node->page_offset; page = node->page[0]; - memset(kmap(page) + off, 0, len); - kunmap(page); + memzero_page(page, off, len); set_page_dirty(page); } @@ -123,9 +118,7 @@ void hfs_bnode_copy(struct hfs_bnode *ds src_page = src_node->page[0]; dst_page = dst_node->page[0]; - memcpy(kmap(dst_page) + dst, kmap(src_page) + src, len); - kunmap(src_page); - kunmap(dst_page); + memcpy_page(dst_page, dst, src_page, src, len); set_page_dirty(dst_page); } @@ -140,9 +133,9 @@ void hfs_bnode_move(struct hfs_bnode *no src += node->page_offset; dst += node->page_offset; page = node->page[0]; - ptr = kmap(page); + ptr = kmap_local_page(page); memmove(ptr + dst, ptr + src, len); - kunmap(page); + kunmap_local(ptr); set_page_dirty(page); } @@ -346,13 +339,14 @@ struct hfs_bnode *hfs_bnode_find(struct if (!test_bit(HFS_BNODE_NEW, &node->flags)) return node; - desc = (struct hfs_bnode_desc *)(kmap(node->page[0]) + node->page_offset); + desc = (struct hfs_bnode_desc *)(kmap_local_page(node->page[0]) + + node->page_offset); node->prev = be32_to_cpu(desc->prev); node->next = be32_to_cpu(desc->next); node->num_recs = be16_to_cpu(desc->num_recs); node->type = desc->type; node->height = desc->height; - kunmap(node->page[0]); + kunmap_local(desc); switch (node->type) { case HFS_NODE_HEADER: @@ -436,14 +430,12 @@ struct hfs_bnode *hfs_bnode_create(struc } pagep = node->page; - memset(kmap(*pagep) + node->page_offset, 0, - min((int)PAGE_SIZE, (int)tree->node_size)); + memzero_page(*pagep, node->page_offset, + min((int)PAGE_SIZE, (int)tree->node_size)); set_page_dirty(*pagep); - kunmap(*pagep); for (i = 1; i < tree->pages_per_bnode; i++) { - memset(kmap(*++pagep), 0, PAGE_SIZE); + memzero_page(*++pagep, 0, PAGE_SIZE); set_page_dirty(*pagep); - kunmap(*pagep); } clear_bit(HFS_BNODE_NEW, &node->flags); wake_up(&node->lock_wq); _ Patches currently in -mm which might be from fmdefrancesco@gmail.com are