From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: [patch 020/118] mm/debug.c: always print flags in dump_page() Date: Thu, 30 Jan 2020 22:12:03 -0800 Message-ID: <20200131061203.ykqerIIrw%akpm@linux-foundation.org> References: <20200130221021.5f0211c56346d5485af07923@linux-foundation.org> Reply-To: linux-kernel@vger.kernel.org Return-path: Received: from mail.kernel.org ([198.145.29.99]:59026 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725907AbgAaGMF (ORCPT ); Fri, 31 Jan 2020 01:12:05 -0500 In-Reply-To: <20200130221021.5f0211c56346d5485af07923@linux-foundation.org> Sender: mm-commits-owner@vger.kernel.org List-Id: mm-commits@vger.kernel.org To: akpm@linux-foundation.org, anshuman.khandual@arm.com, cai@lca.pw, dan.j.williams@intel.com, david@redhat.com, linux-mm@kvack.org, mgorman@techsingularity.net, mhocko@kernel.org, mhocko@suse.com, mm-commits@vger.kernel.org, osalvador@suse.de, pavel.tatashin@microsoft.com, rcampbell@nvidia.com, rppt@linux.ibm.com, torvalds@linux-foundation.org, vbabka@suse.cz From: Vlastimil Babka Subject: mm/debug.c: always print flags in dump_page() Commit 76a1850e4572 ("mm/debug.c: __dump_page() prints an extra line") inadvertently removed printing of page flags for pages that are neither anon nor ksm nor have a mapping. Fix that. Using pr_cont() again would be a solution, but the commit explicitly removed its use. Avoiding the danger of mixing up split lines from multiple CPUs might be beneficial for near-panic dumps like this, so fix this without reintroducing pr_cont(). Link: http://lkml.kernel.org/r/9f884d5c-ca60-dc7b-219c-c081c755fab6@suse.cz Fixes: 76a1850e4572 ("mm/debug.c: __dump_page() prints an extra line") Signed-off-by: Vlastimil Babka Reported-by: Anshuman Khandual Reported-by: Michal Hocko Acked-by: Michal Hocko Cc: David Hildenbrand Cc: Qian Cai Cc: Oscar Salvador Cc: Mel Gorman Cc: Mike Rapoport Cc: Dan Williams Cc: Pavel Tatashin Cc: Ralph Campbell Signed-off-by: Andrew Morton --- mm/debug.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) --- a/mm/debug.c~mm-debug-always-print-flags-in-dump_page +++ a/mm/debug.c @@ -47,6 +47,7 @@ void __dump_page(struct page *page, cons struct address_space *mapping; bool page_poisoned = PagePoisoned(page); int mapcount; + char *type = ""; /* * If struct page is poisoned don't access Page*() functions as that @@ -78,9 +79,9 @@ void __dump_page(struct page *page, cons page, page_ref_count(page), mapcount, page->mapping, page_to_pgoff(page)); if (PageKsm(page)) - pr_warn("ksm flags: %#lx(%pGp)\n", page->flags, &page->flags); + type = "ksm "; else if (PageAnon(page)) - pr_warn("anon flags: %#lx(%pGp)\n", page->flags, &page->flags); + type = "anon "; else if (mapping) { if (mapping->host && mapping->host->i_dentry.first) { struct dentry *dentry; @@ -88,10 +89,11 @@ void __dump_page(struct page *page, cons pr_warn("%ps name:\"%pd\"\n", mapping->a_ops, dentry); } else pr_warn("%ps\n", mapping->a_ops); - pr_warn("flags: %#lx(%pGp)\n", page->flags, &page->flags); } BUILD_BUG_ON(ARRAY_SIZE(pageflag_names) != __NR_PAGEFLAGS + 1); + pr_warn("%sflags: %#lx(%pGp)\n", type, page->flags, &page->flags); + hex_only: print_hex_dump(KERN_WARNING, "raw: ", DUMP_PREFIX_NONE, 32, sizeof(unsigned long), page, _