From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ed1-f72.google.com (mail-ed1-f72.google.com [209.85.208.72]) by kanga.kvack.org (Postfix) with ESMTP id 56C6E6B087F for ; Fri, 16 Nov 2018 03:30:36 -0500 (EST) Received: by mail-ed1-f72.google.com with SMTP id c53so2675216edc.9 for ; Fri, 16 Nov 2018 00:30:36 -0800 (PST) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id m4-v6sor7102259eja.14.2018.11.16.00.30.34 for (Google Transport Security); Fri, 16 Nov 2018 00:30:34 -0800 (PST) From: Michal Hocko Subject: [PATCH 1/5] mm: print more information about mapping in __dump_page Date: Fri, 16 Nov 2018 09:30:16 +0100 Message-Id: <20181116083020.20260-2-mhocko@kernel.org> In-Reply-To: <20181116083020.20260-1-mhocko@kernel.org> References: <20181116083020.20260-1-mhocko@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: Oscar Salvador , Baoquan He , Anshuman Khandual , linux-mm@kvack.org, LKML , Michal Hocko From: Michal Hocko __dump_page prints the mapping pointer but that is quite unhelpful for many reports because the pointer itself only helps to distinguish anon/ksm mappings from other ones (because of lowest bits set). Sometimes it would be much more helpful to know what kind of mapping that is actually and if we know this is a file mapping then also try to resolve the dentry name. Signed-off-by: Michal Hocko --- mm/debug.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/mm/debug.c b/mm/debug.c index cdacba12e09a..a33177bfc856 100644 --- a/mm/debug.c +++ b/mm/debug.c @@ -44,6 +44,7 @@ const struct trace_print_flags vmaflag_names[] = { void __dump_page(struct page *page, const char *reason) { + struct address_space *mapping = page_mapping(page); bool page_poisoned = PagePoisoned(page); int mapcount; @@ -70,6 +71,18 @@ void __dump_page(struct page *page, const char *reason) if (PageCompound(page)) pr_cont(" compound_mapcount: %d", compound_mapcount(page)); pr_cont("\n"); + if (PageAnon(page)) + pr_emerg("anon "); + else if (PageKsm(page)) + pr_emerg("ksm "); + else if (mapping) { + pr_emerg("%ps ", mapping->a_ops); + if (mapping->host->i_dentry.first) { + struct dentry *dentry; + dentry = container_of(mapping->host->i_dentry.first, struct dentry, d_u.d_alias); + pr_emerg("name:\"%*s\" ", dentry->d_name.len, dentry->d_name.name); + } + } BUILD_BUG_ON(ARRAY_SIZE(pageflag_names) != __NR_PAGEFLAGS + 1); pr_emerg("flags: %#lx(%pGp)\n", page->flags, &page->flags); -- 2.19.1