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 X-Spam-Level: X-Spam-Status: No, score=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 31072C433ED for ; Tue, 27 Apr 2021 03:29:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 04728613BC for ; Tue, 27 Apr 2021 03:29:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234361AbhD0Dab (ORCPT ); Mon, 26 Apr 2021 23:30:31 -0400 Received: from foss.arm.com ([217.140.110.172]:43366 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230338AbhD0Da3 (ORCPT ); Mon, 26 Apr 2021 23:30:29 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 59E0CD6E; Mon, 26 Apr 2021 20:29:47 -0700 (PDT) Received: from [10.163.75.249] (unknown [10.163.75.249]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id E3F293F694; Mon, 26 Apr 2021 20:29:45 -0700 (PDT) From: Anshuman Khandual Subject: Re: [PATCH 2/6] mm/debug: Factor PagePoisoned out of __dump_page To: "Matthew Wilcox (Oracle)" , linux-mm@kvack.org Cc: Andrew Morton , linux-kernel@vger.kernel.org References: <20210416231531.2521383-1-willy@infradead.org> <20210416231531.2521383-3-willy@infradead.org> Message-ID: <22cb33f0-444e-8b04-13eb-b4e2cff949d2@arm.com> Date: Tue, 27 Apr 2021 09:00:38 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20210416231531.2521383-3-willy@infradead.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 4/17/21 4:45 AM, Matthew Wilcox (Oracle) wrote: > Move the PagePoisoned test into dump_page(). Skip the hex print > for poisoned pages -- we know they're full of ffffffff. Move the > reason printing from __dump_page() to dump_page(). > > Signed-off-by: Matthew Wilcox (Oracle) > --- > mm/debug.c | 25 +++++++------------------ > 1 file changed, 7 insertions(+), 18 deletions(-) > > diff --git a/mm/debug.c b/mm/debug.c > index 84cdcd0f7bd3..e73fe0a8ec3d 100644 > --- a/mm/debug.c > +++ b/mm/debug.c > @@ -42,11 +42,10 @@ const struct trace_print_flags vmaflag_names[] = { > {0, NULL} > }; > > -static void __dump_page(struct page *page, const char *reason) > +static void __dump_page(struct page *page) > { > struct page *head = compound_head(page); > struct address_space *mapping; > - bool page_poisoned = PagePoisoned(page); > bool compound = PageCompound(page); > /* > * Accessing the pageblock without the zone lock. It could change to > @@ -58,16 +57,6 @@ static void __dump_page(struct page *page, const char *reason) > int mapcount; > char *type = ""; > > - /* > - * If struct page is poisoned don't access Page*() functions as that > - * leads to recursive loop. Page*() check for poisoned pages, and calls > - * dump_page() when detected. > - */ > - if (page_poisoned) { > - pr_warn("page:%px is uninitialized and poisoned", page); > - goto hex_only; > - } > - > if (page < head || (page >= head + MAX_ORDER_NR_PAGES)) { > /* > * Corrupt page, so we cannot call page_mapping. Instead, do a > @@ -173,8 +162,6 @@ static void __dump_page(struct page *page, const char *reason) > > pr_warn("%sflags: %#lx(%pGp)%s\n", type, head->flags, &head->flags, > page_cma ? " CMA" : ""); > - > -hex_only: > print_hex_dump(KERN_WARNING, "raw: ", DUMP_PREFIX_NONE, 32, > sizeof(unsigned long), page, > sizeof(struct page), false); > @@ -182,14 +169,16 @@ static void __dump_page(struct page *page, const char *reason) > print_hex_dump(KERN_WARNING, "head: ", DUMP_PREFIX_NONE, 32, > sizeof(unsigned long), head, > sizeof(struct page), false); > - > - if (reason) > - pr_warn("page dumped because: %s\n", reason); > } > > void dump_page(struct page *page, const char *reason) > { > - __dump_page(page, reason); > + if (PagePoisoned(page)) > + pr_warn("page:%p is uninitialized and poisoned", page); > + else > + __dump_page(page); > + if (reason) > + pr_warn("page dumped because: %s\n", reason); > dump_page_owner(page); > } > EXPORT_SYMBOL(dump_page); > Reviewed-by: Anshuman Khandual