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 C5A5BECAAD3 for ; Sun, 4 Sep 2022 14:03:36 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id D39378D0040; Sun, 4 Sep 2022 10:03:35 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id CE89B8D0031; Sun, 4 Sep 2022 10:03:35 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id BB05A8D0040; Sun, 4 Sep 2022 10:03:35 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id A371D8D0031 for ; Sun, 4 Sep 2022 10:03:35 -0400 (EDT) Received: from smtpin08.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 6C254A05D6 for ; Sun, 4 Sep 2022 14:03:35 +0000 (UTC) X-FDA: 79874570790.08.433A26E Received: from chinatelecom.cn (prt-mail.chinatelecom.cn [42.123.76.228]) by imf28.hostedemail.com (Postfix) with ESMTP id D8462C0084 for ; Sun, 4 Sep 2022 14:03:33 +0000 (UTC) HMM_SOURCE_IP:172.18.0.218:42302.846211882 HMM_ATTACHE_NUM:0000 HMM_SOURCE_TYPE:SMTP Received: from clientip-222.210.155.225 (unknown [172.18.0.218]) by chinatelecom.cn (HERMES) with SMTP id 013A32801A6; Sun, 4 Sep 2022 22:03:25 +0800 (CST) X-189-SAVE-TO-SEND: +lic121@chinatelecom.cn Received: from ([172.18.0.218]) by app0025 with ESMTP id fcb6896dd8644185bf2f35d5547c90c4 for mike.kravetz@oracle.com; Sun, 04 Sep 2022 22:03:30 CST X-Transaction-ID: fcb6896dd8644185bf2f35d5547c90c4 X-Real-From: lic121@chinatelecom.cn X-Receive-IP: 172.18.0.218 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] mm: use mem_map_offset instead of mem_map_next Date: Sun, 4 Sep 2022 14:02:41 +0000 Message-Id: <1662300161-22049-1-git-send-email-lic121@chinatelecom.cn> X-Mailer: git-send-email 1.8.3.1 ARC-Authentication-Results: i=1; imf28.hostedemail.com; dkim=none; spf=pass (imf28.hostedemail.com: domain of lic121@chinatelecom.cn designates 42.123.76.228 as permitted sender) smtp.mailfrom=lic121@chinatelecom.cn; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1662300214; a=rsa-sha256; cv=none; b=nbhz7x2QTq5YnpBQG+JxJXfAw9tF4ggSKxuPCDi2eyGQeoeH7uee00R1tWsKDFggp5+gqY SL08Q/N4JT0JmELlZl4CJfMkHsRY4uKgL0ypDzNPyJyQ+n0rMGHMUPh+CIlU1abdm1JHwP +IJ5RZ20v9gj8P3XX6y60jTRvmDeZ/s= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1662300214; 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=oQ61wnfQ32H/Fn8G1SxHL+GTqVt8ebodQRm7DyLkAME=; b=u7rnHd/ENNHjeUk24uttWBONBcm1cz32Joj7eDls9Bjy8EiaxyWTzMZLwBGLt2ewORPdLB fYYfxEt1GDAfm1tit9mRx+1o2Tl3NXK6knV66C/QNgHg/bl4l+xK8vHDWPXB4s8aD29t5r /CTyAXOGarsTAkqRCcQwFrZSa1c86Ug= Authentication-Results: imf28.hostedemail.com; dkim=none; spf=pass (imf28.hostedemail.com: domain of lic121@chinatelecom.cn designates 42.123.76.228 as permitted sender) smtp.mailfrom=lic121@chinatelecom.cn; dmarc=none X-Rspamd-Server: rspam06 X-Stat-Signature: na1zb9e7ogwkizk4rg5qskhrg3ey8bax X-Rspam-User: X-Rspamd-Queue-Id: D8462C0084 X-HE-Tag: 1662300213-752662 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") --- 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..56d74cdbdbf9 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(p, 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