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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 12F41ECAAD5 for ; Mon, 5 Sep 2022 06:10:05 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 9BF36801A9; Mon, 5 Sep 2022 02:10:04 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 96F2B8019F; Mon, 5 Sep 2022 02:10:04 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 85DDF801A9; Mon, 5 Sep 2022 02:10:04 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 730C08019F for ; Mon, 5 Sep 2022 02:10:04 -0400 (EDT) Received: from smtpin07.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 453FE160CE9 for ; Mon, 5 Sep 2022 06:10:04 +0000 (UTC) X-FDA: 79877006328.07.3F4F004 Received: from chinatelecom.cn (prt-mail.chinatelecom.cn [42.123.76.221]) by imf23.hostedemail.com (Postfix) with ESMTP id 6AB32140077 for ; Mon, 5 Sep 2022 06:10:02 +0000 (UTC) HMM_SOURCE_IP:172.18.0.48:60476.944095620 HMM_ATTACHE_NUM:0000 HMM_SOURCE_TYPE:SMTP Received: from clientip-110.188.55.54 (unknown [172.18.0.48]) by chinatelecom.cn (HERMES) with SMTP id 9CB262800B3; Mon, 5 Sep 2022 14:09:53 +0800 (CST) X-189-SAVE-TO-SEND: +lic121@chinatelecom.cn Received: from ([172.18.0.48]) by app0024 with ESMTP id a25791cbf4fa4f0aa6e5b46cd6815d0a for mike.kravetz@oracle.com; Mon, 05 Sep 2022 14:09:58 CST X-Transaction-ID: a25791cbf4fa4f0aa6e5b46cd6815d0a X-Real-From: lic121@chinatelecom.cn X-Receive-IP: 172.18.0.48 X-MEDUSA-Status: 0 From: Cheng Li To: mike.kravetz@oracle.com, akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: Cheng Li Subject: [PATCH v2] mm: use mem_map_offset instead of mem_map_next Date: Mon, 5 Sep 2022 06:09:19 +0000 Message-Id: <1662358159-22780-1-git-send-email-lic121@chinatelecom.cn> X-Mailer: git-send-email 1.8.3.1 ARC-Authentication-Results: i=1; imf23.hostedemail.com; dkim=none; spf=pass (imf23.hostedemail.com: domain of lic121@chinatelecom.cn designates 42.123.76.221 as permitted sender) smtp.mailfrom=lic121@chinatelecom.cn; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1662358203; a=rsa-sha256; cv=none; b=FEIhubuzvr9DVhOtj3SdiKvHHU3kp5bxi2A1bQjI0eJitPXALOVRnzrwk45Ce9GGMBFpAx hZSKloACa8mpeoSfmPdpz8pbqeUjYH+q2svXGVQ8Htq2hNQ8z2QZCheweRDg+lX2YJG0Vq wxbVEfO2D+qAQYaSSmnWMQZV6RvU+ic= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1662358203; h=from:from:sender:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:content-type: content-transfer-encoding:in-reply-to:references; bh=4OCJF1PSjHJPCX2/lIOOdJlEEO2Qx+vrx7j+wW3M2xc=; b=JzG0YA1r5iXYwuBfxUP2H6n/StSBrixHsvUhPqkATEtWPTUVjA+iQBFvJo97t62OL6CGQU aNDMMUnb7NcFof5wV1RbYNCJrl005R1NRAdOgcoFSbH5Pdzg7qClF0FCE0A13EBtnUaZtT +5WmxggWze4lXcyUWVy5jDVh/Tkx3Yc= Authentication-Results: imf23.hostedemail.com; dkim=none; spf=pass (imf23.hostedemail.com: domain of lic121@chinatelecom.cn designates 42.123.76.221 as permitted sender) smtp.mailfrom=lic121@chinatelecom.cn; dmarc=none X-Rspamd-Server: rspam06 X-Stat-Signature: 1tapt1wpwougjux4i81jf54nitja4ogg X-Rspam-User: X-Rspamd-Queue-Id: 6AB32140077 X-HE-Tag: 1662358202-356094 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: To handle discontiguity case, mem_map_next() has a parameter named `offset`. As a function caller, one would be confused why "get next entry" needs a parameter named "offset". The other drawback of mem_map_next() is that the callers must take care of the map between parameter "iter" and "offset", otherwise we may get an hole or duplication during iteration. So we use mem_map_offset instead of mem_map_next. Signed-off-by: Cheng Li Fixes: 69d177c2fc70 ("hugetlbfs: handle pages higher order than MAX_ORDER") --- Notes: v2: - fix build error mm/hugetlb.c | 25 +++++++++++++++---------- mm/internal.h | 16 ++-------------- mm/memory.c | 21 ++++++++++----------- 3 files changed, 27 insertions(+), 35 deletions(-) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index e070b8593b37..a9592f69bf82 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -1308,12 +1308,13 @@ static void __destroy_compound_gigantic_page(struct page *page, { int i; int nr_pages = 1 << order; - struct page *p = page + 1; + struct page *p; atomic_set(compound_mapcount_ptr(page), 0); atomic_set(compound_pincount_ptr(page), 0); - for (i = 1; i < nr_pages; i++, p = mem_map_next(p, page, i)) { + for (i = 1; i < nr_pages; i++) { + p = mem_map_offset(page, i); p->mapping = NULL; clear_compound_head(p); if (!demote) @@ -1530,7 +1531,7 @@ static void add_hugetlb_page(struct hstate *h, struct page *page, static void __update_and_free_page(struct hstate *h, struct page *page) { int i; - struct page *subpage = page; + struct page *subpage; if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) return; @@ -1561,8 +1562,8 @@ static void __update_and_free_page(struct hstate *h, struct page *page) if (unlikely(PageHWPoison(page))) hugetlb_clear_page_hwpoison(page); - for (i = 0; i < pages_per_huge_page(h); - i++, subpage = mem_map_next(subpage, page, i)) { + for (i = 0; i < pages_per_huge_page(h); i++) { + subpage = mem_map_offset(page, i); subpage->flags &= ~(1 << PG_locked | 1 << PG_error | 1 << PG_referenced | 1 << PG_dirty | 1 << PG_active | 1 << PG_private | @@ -1769,13 +1770,15 @@ static bool __prep_compound_gigantic_page(struct page *page, unsigned int order, { int i, j; int nr_pages = 1 << order; - struct page *p = page + 1; + struct page *p; /* we rely on prep_new_huge_page to set the destructor */ set_compound_order(page, order); __ClearPageReserved(page); __SetPageHead(page); - for (i = 1; i < nr_pages; i++, p = mem_map_next(p, page, i)) { + for (i = 1; i < nr_pages; i++) { + p = mem_map_offset(page, i); + /* * For gigantic hugepages allocated through bootmem at * boot, it's safer to be consistent with the not-gigantic @@ -1822,14 +1825,16 @@ static bool __prep_compound_gigantic_page(struct page *page, unsigned int order, out_error: /* undo tail page modifications made above */ - p = page + 1; - for (j = 1; j < i; j++, p = mem_map_next(p, page, j)) { + for (j = 1; j < i; j++) { + p = mem_map_offset(page, j); clear_compound_head(p); set_page_refcounted(p); } /* need to clear PG_reserved on remaining tail pages */ - for (; j < nr_pages; j++, p = mem_map_next(p, page, j)) + for (; j < nr_pages; j++) { + p = mem_map_offset(page, j); __ClearPageReserved(p); + } set_compound_order(page, 0); #ifdef CONFIG_64BIT page[1].compound_nr = 0; diff --git a/mm/internal.h b/mm/internal.h index 785409805ed7..1012a305a60f 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -646,25 +646,13 @@ static inline void vunmap_range_noflush(unsigned long start, unsigned long end) */ static inline struct page *mem_map_offset(struct page *base, int offset) { - if (unlikely(offset >= MAX_ORDER_NR_PAGES)) - return nth_page(base, offset); - return base + offset; -} - -/* - * Iterator over all subpages within the maximally aligned gigantic - * page 'base'. Handle any discontiguity in the mem_map. - */ -static inline struct page *mem_map_next(struct page *iter, - struct page *base, int offset) -{ - if (unlikely((offset & (MAX_ORDER_NR_PAGES - 1)) == 0)) { + if (unlikely(offset >= MAX_ORDER_NR_PAGES)) { unsigned long pfn = page_to_pfn(base) + offset; if (!pfn_valid(pfn)) return NULL; return pfn_to_page(pfn); } - return iter + 1; + return base + offset; } /* Memory initialisation debug and verification */ diff --git a/mm/memory.c b/mm/memory.c index 4ba73f5aa8bb..32179c4fd1a5 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -5637,11 +5637,11 @@ static void clear_gigantic_page(struct page *page, unsigned int pages_per_huge_page) { int i; - struct page *p = page; + struct page *p; might_sleep(); - for (i = 0; i < pages_per_huge_page; - i++, p = mem_map_next(p, page, i)) { + for (i = 0; i < pages_per_huge_page; i++) { + p = mem_map_offset(page, i); cond_resched(); clear_user_highpage(p, addr + i * PAGE_SIZE); } @@ -5677,13 +5677,12 @@ static void copy_user_gigantic_page(struct page *dst, struct page *src, struct page *dst_base = dst; struct page *src_base = src; - for (i = 0; i < pages_per_huge_page; ) { + for (i = 0; i < pages_per_huge_page; i++) { + dst = mem_map_offset(dst_base, i); + src = mem_map_offset(src_base, i); + cond_resched(); copy_user_highpage(dst, src, addr + i*PAGE_SIZE, vma); - - i++; - dst = mem_map_next(dst, dst_base, i); - src = mem_map_next(src, src_base, i); } } @@ -5730,10 +5729,10 @@ long copy_huge_page_from_user(struct page *dst_page, void *page_kaddr; unsigned long i, rc = 0; unsigned long ret_val = pages_per_huge_page * PAGE_SIZE; - struct page *subpage = dst_page; + struct page *subpage; - for (i = 0; i < pages_per_huge_page; - i++, subpage = mem_map_next(subpage, dst_page, i)) { + for (i = 0; i < pages_per_huge_page; i++) { + subpage = mem_map_offset(dst_page, i); if (allow_pagefault) page_kaddr = kmap(subpage); else -- 1.8.3.1