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 96A55C25B07 for ; Wed, 10 Aug 2022 23:40:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229722AbiHJXkp (ORCPT ); Wed, 10 Aug 2022 19:40:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36354 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233094AbiHJXkg (ORCPT ); Wed, 10 Aug 2022 19:40:36 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BE20FB21 for ; Wed, 10 Aug 2022 16:40:34 -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 4948CB81DDA for ; Wed, 10 Aug 2022 23:40:33 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 01F28C433D6; Wed, 10 Aug 2022 23:40:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1660174832; bh=2FX+ZlU3rnnqiUrTXE9JQfXthBee77MDAzAWGT/Vz5E=; h=Date:To:From:Subject:From; b=2lk79uCBW8c859zewfm1nJnP4+USC9ubPEVJT4srd5r8GCyBqcuTbBjVizJaigLzC ofr3GltL22FL68Vjt+y5ChwQB63oIyMWwc6DKGylI2ySOBmvqdqSPonN7iRkZjx9V8 UySbdkMrKhq9tIWEBc9+zaB5cu/yv6U4bzHJwpls= Date: Wed, 10 Aug 2022 16:40:31 -0700 To: mm-commits@vger.kernel.org, willy@infradead.org, songmuchun@bytedance.com, slava@dubeyko.com, keescook@chromium.org, ira.weiny@intel.com, bvanassche@acm.org, axboe@kernel.dk, fmdefrancesco@gmail.com, akpm@linux-foundation.org From: Andrew Morton Subject: + hfsplus-convert-kmap-to-kmap_local_page-in-bnodec.patch added to mm-nonmm-unstable branch Message-Id: <20220810234032.01F28C433D6@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The patch titled Subject: hfsplus: convert kmap() to kmap_local_page() in bnode.c has been added to the -mm mm-nonmm-unstable branch. Its filename is hfsplus-convert-kmap-to-kmap_local_page-in-bnodec.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/hfsplus-convert-kmap-to-kmap_local_page-in-bnodec.patch This patch will later appear in the mm-nonmm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: "Fabio M. De Francesco" Subject: hfsplus: convert kmap() to kmap_local_page() in bnode.c Date: Tue, 9 Aug 2022 22:31:03 +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/20220809203105.26183-3-fmdefrancesco@gmail.com Signed-off-by: Fabio M. De Francesco Suggested-by: Ira Weiny Reviewed-by: Ira Weiny Reviewed-by: Viacheslav Dubeyko Cc: Bart Van Assche Cc: Jens Axboe Cc: Kees Cook Cc: Matthew Wilcox Cc: Muchun Song Signed-off-by: Andrew Morton --- fs/hfsplus/bnode.c | 105 +++++++++++++++++++------------------------ 1 file changed, 48 insertions(+), 57 deletions(-) --- a/fs/hfsplus/bnode.c~hfsplus-convert-kmap-to-kmap_local_page-in-bnodec +++ a/fs/hfsplus/bnode.c @@ -29,14 +29,12 @@ void hfs_bnode_read(struct hfs_bnode *no off &= ~PAGE_MASK; l = min_t(int, len, PAGE_SIZE - off); - memcpy(buf, kmap(*pagep) + off, l); - kunmap(*pagep); + memcpy_from_page(buf, *pagep, off, l); while ((len -= l) != 0) { buf += l; l = min_t(int, len, PAGE_SIZE); - memcpy(buf, kmap(*++pagep), l); - kunmap(*pagep); + memcpy_from_page(buf, *++pagep, 0, l); } } @@ -82,16 +80,14 @@ void hfs_bnode_write(struct hfs_bnode *n off &= ~PAGE_MASK; l = min_t(int, len, PAGE_SIZE - off); - memcpy(kmap(*pagep) + off, buf, l); + memcpy_to_page(*pagep, off, buf, l); set_page_dirty(*pagep); - kunmap(*pagep); while ((len -= l) != 0) { buf += l; l = min_t(int, len, PAGE_SIZE); - memcpy(kmap(*++pagep), buf, l); + memcpy_to_page(*++pagep, 0, buf, l); set_page_dirty(*pagep); - kunmap(*pagep); } } @@ -112,15 +108,13 @@ void hfs_bnode_clear(struct hfs_bnode *n off &= ~PAGE_MASK; l = min_t(int, len, PAGE_SIZE - off); - memset(kmap(*pagep) + off, 0, l); + memzero_page(*pagep, off, l); set_page_dirty(*pagep); - kunmap(*pagep); while ((len -= l) != 0) { l = min_t(int, len, PAGE_SIZE); - memset(kmap(*++pagep), 0, l); + memzero_page(*++pagep, 0, l); set_page_dirty(*pagep); - kunmap(*pagep); } } @@ -142,24 +136,20 @@ void hfs_bnode_copy(struct hfs_bnode *ds if (src == dst) { l = min_t(int, len, PAGE_SIZE - src); - memcpy(kmap(*dst_page) + src, kmap(*src_page) + src, l); - kunmap(*src_page); + memcpy_page(*dst_page, src, *src_page, src, l); set_page_dirty(*dst_page); - kunmap(*dst_page); while ((len -= l) != 0) { l = min_t(int, len, PAGE_SIZE); - memcpy(kmap(*++dst_page), kmap(*++src_page), l); - kunmap(*src_page); + memcpy_page(*++dst_page, 0, *++src_page, 0, l); set_page_dirty(*dst_page); - kunmap(*dst_page); } } else { void *src_ptr, *dst_ptr; do { - src_ptr = kmap(*src_page) + src; - dst_ptr = kmap(*dst_page) + dst; + dst_ptr = kmap_local_page(*dst_page) + dst; + src_ptr = kmap_local_page(*src_page) + src; if (PAGE_SIZE - src < PAGE_SIZE - dst) { l = PAGE_SIZE - src; src = 0; @@ -171,9 +161,9 @@ void hfs_bnode_copy(struct hfs_bnode *ds } l = min(len, l); memcpy(dst_ptr, src_ptr, l); - kunmap(*src_page); + kunmap_local(src_ptr); set_page_dirty(*dst_page); - kunmap(*dst_page); + kunmap_local(dst_ptr); if (!dst) dst_page++; else @@ -185,6 +175,7 @@ void hfs_bnode_copy(struct hfs_bnode *ds void hfs_bnode_move(struct hfs_bnode *node, int dst, int src, int len) { struct page **src_page, **dst_page; + void *src_ptr, *dst_ptr; int l; hfs_dbg(BNODE_MOD, "movebytes: %u,%u,%u\n", dst, src, len); @@ -202,27 +193,28 @@ void hfs_bnode_move(struct hfs_bnode *no if (src == dst) { while (src < len) { - memmove(kmap(*dst_page), kmap(*src_page), src); - kunmap(*src_page); + dst_ptr = kmap_local_page(*dst_page); + src_ptr = kmap_local_page(*src_page); + memmove(dst_ptr, src_ptr, src); + kunmap_local(src_ptr); set_page_dirty(*dst_page); - kunmap(*dst_page); + kunmap_local(dst_ptr); len -= src; src = PAGE_SIZE; src_page--; dst_page--; } src -= len; - memmove(kmap(*dst_page) + src, - kmap(*src_page) + src, len); - kunmap(*src_page); + dst_ptr = kmap_local_page(*dst_page); + src_ptr = kmap_local_page(*src_page); + memmove(dst_ptr + src, src_ptr + src, len); + kunmap_local(src_ptr); set_page_dirty(*dst_page); - kunmap(*dst_page); + kunmap_local(dst_ptr); } else { - void *src_ptr, *dst_ptr; - do { - src_ptr = kmap(*src_page) + src; - dst_ptr = kmap(*dst_page) + dst; + dst_ptr = kmap_local_page(*dst_page) + dst; + src_ptr = kmap_local_page(*src_page) + src; if (src < dst) { l = src; src = PAGE_SIZE; @@ -234,9 +226,9 @@ void hfs_bnode_move(struct hfs_bnode *no } l = min(len, l); memmove(dst_ptr - l, src_ptr - l, l); - kunmap(*src_page); + kunmap_local(src_ptr); set_page_dirty(*dst_page); - kunmap(*dst_page); + kunmap_local(dst_ptr); if (dst == PAGE_SIZE) dst_page--; else @@ -251,26 +243,27 @@ void hfs_bnode_move(struct hfs_bnode *no if (src == dst) { l = min_t(int, len, PAGE_SIZE - src); - memmove(kmap(*dst_page) + src, - kmap(*src_page) + src, l); - kunmap(*src_page); + + dst_ptr = kmap_local_page(*dst_page) + src; + src_ptr = kmap_local_page(*src_page) + src; + memmove(dst_ptr, src_ptr, l); + kunmap_local(src_ptr); set_page_dirty(*dst_page); - kunmap(*dst_page); + kunmap_local(dst_ptr); while ((len -= l) != 0) { l = min_t(int, len, PAGE_SIZE); - memmove(kmap(*++dst_page), - kmap(*++src_page), l); - kunmap(*src_page); + dst_ptr = kmap_local_page(*++dst_page); + src_ptr = kmap_local_page(*++src_page); + memmove(dst_ptr, src_ptr, l); + kunmap_local(src_ptr); set_page_dirty(*dst_page); - kunmap(*dst_page); + kunmap_local(dst_ptr); } } else { - void *src_ptr, *dst_ptr; - do { - src_ptr = kmap(*src_page) + src; - dst_ptr = kmap(*dst_page) + dst; + dst_ptr = kmap_local_page(*dst_page) + dst; + src_ptr = kmap_local_page(*src_page) + src; if (PAGE_SIZE - src < PAGE_SIZE - dst) { l = PAGE_SIZE - src; @@ -283,9 +276,9 @@ void hfs_bnode_move(struct hfs_bnode *no } l = min(len, l); memmove(dst_ptr, src_ptr, l); - kunmap(*src_page); + kunmap_local(src_ptr); set_page_dirty(*dst_page); - kunmap(*dst_page); + kunmap_local(dst_ptr); if (!dst) dst_page++; else @@ -498,14 +491,14 @@ 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: @@ -589,14 +582,12 @@ struct hfs_bnode *hfs_bnode_create(struc } pagep = node->page; - memset(kmap(*pagep) + node->page_offset, 0, - min_t(int, PAGE_SIZE, tree->node_size)); + memzero_page(*pagep, node->page_offset, + min_t(int, PAGE_SIZE, 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 hfsplus-unmap-the-page-in-the-fail_page-label.patch hfsplus-convert-kmap-to-kmap_local_page-in-bnodec.patch hfsplus-convert-kmap-to-kmap_local_page-in-bitmapc.patch hfsplus-convert-kmap-to-kmap_local_page-in-btreec.patch