From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk0-f197.google.com (mail-qk0-f197.google.com [209.85.220.197]) by kanga.kvack.org (Postfix) with ESMTP id 348CB6B0003 for ; Fri, 2 Mar 2018 06:01:50 -0500 (EST) Received: by mail-qk0-f197.google.com with SMTP id s82so7324199qke.1 for ; Fri, 02 Mar 2018 03:01:50 -0800 (PST) Received: from mx1.redhat.com (mx3-rdu2.redhat.com. [66.187.233.73]) by mx.google.com with ESMTPS id x13si59696qta.408.2018.03.02.03.01.49 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 02 Mar 2018 03:01:49 -0800 (PST) From: Daniel Vacek Subject: [PATCH v2] mm/page_alloc: fix memmap_init_zone pageblock alignment Date: Fri, 2 Mar 2018 12:01:37 +0100 Message-Id: <1519988497-28941-1-git-send-email-neelx@redhat.com> In-Reply-To: <1519908465-12328-1-git-send-email-neelx@redhat.com> References: <1519908465-12328-1-git-send-email-neelx@redhat.com> Sender: owner-linux-mm@kvack.org List-ID: To: linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: Andrew Morton , Michal Hocko , Vlastimil Babka , Mel Gorman , Pavel Tatashin , Paul Burton , Daniel Vacek , stable@vger.kernel.org BUG at mm/page_alloc.c:1913 > VM_BUG_ON(page_zone(start_page) != page_zone(end_page)); Commit b92df1de5d28 ("mm: page_alloc: skip over regions of invalid pfns where possible") introduced a bug where move_freepages() triggers a VM_BUG_ON() on uninitialized page structure due to pageblock alignment. To fix this, simply align the skipped pfns in memmap_init_zone() the same way as in move_freepages_block(). Fixes: b92df1de5d28 ("mm: page_alloc: skip over regions of invalid pfns where possible") Signed-off-by: Daniel Vacek Cc: stable@vger.kernel.org --- mm/memblock.c | 13 ++++++------- mm/page_alloc.c | 9 +++++++-- 2 files changed, 13 insertions(+), 9 deletions(-) diff --git a/mm/memblock.c b/mm/memblock.c index 5a9ca2a1751b..2a5facd236bb 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -1101,13 +1101,12 @@ void __init_memblock __next_mem_pfn_range(int *idx, int nid, *out_nid = r->nid; } -unsigned long __init_memblock memblock_next_valid_pfn(unsigned long pfn, - unsigned long max_pfn) +unsigned long __init_memblock memblock_next_valid_pfn(unsigned long pfn) { struct memblock_type *type = &memblock.memory; unsigned int right = type->cnt; unsigned int mid, left = 0; - phys_addr_t addr = PFN_PHYS(pfn + 1); + phys_addr_t addr = PFN_PHYS(++pfn); do { mid = (right + left) / 2; @@ -1118,15 +1117,15 @@ unsigned long __init_memblock memblock_next_valid_pfn(unsigned long pfn, type->regions[mid].size)) left = mid + 1; else { - /* addr is within the region, so pfn + 1 is valid */ - return min(pfn + 1, max_pfn); + /* addr is within the region, so pfn is valid */ + return pfn; } } while (left < right); if (right == type->cnt) - return max_pfn; + return -1UL; else - return min(PHYS_PFN(type->regions[right].base), max_pfn); + return PHYS_PFN(type->regions[right].base); } /** diff --git a/mm/page_alloc.c b/mm/page_alloc.c index cb416723538f..eb27ccb50928 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -5359,9 +5359,14 @@ void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone, /* * Skip to the pfn preceding the next valid one (or * end_pfn), such that we hit a valid pfn (or end_pfn) - * on our next iteration of the loop. + * on our next iteration of the loop. Note that it needs + * to be pageblock aligned even when the region itself + * is not as move_freepages_block() can shift ahead of + * the valid region but still depends on correct page + * metadata. */ - pfn = memblock_next_valid_pfn(pfn, end_pfn) - 1; + pfn = (memblock_next_valid_pfn(pfn) & + ~(pageblock_nr_pages-1)) - 1; #endif continue; } -- 2.16.2 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org