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 8D73EC433EF for ; Tue, 29 Mar 2022 19:13:52 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 0EE438D0005; Tue, 29 Mar 2022 15:13:52 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 09FA48D0002; Tue, 29 Mar 2022 15:13:52 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E82288D0005; Tue, 29 Mar 2022 15:13:51 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0033.hostedemail.com [216.40.44.33]) by kanga.kvack.org (Postfix) with ESMTP id DAD188D0002 for ; Tue, 29 Mar 2022 15:13:51 -0400 (EDT) Received: from smtpin19.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 967D518288A2A for ; Tue, 29 Mar 2022 19:13:51 +0000 (UTC) X-FDA: 79298373462.19.37B6509 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by imf21.hostedemail.com (Postfix) with ESMTP id 49B781C000C for ; Tue, 29 Mar 2022 19:13:51 +0000 (UTC) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 2372421980; Tue, 29 Mar 2022 19:13:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1648581230; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=8vITF4y5I3Qh2gV4oA1G6ENMes/c4yf/oaIqSyELU/A=; b=ck65D7u93Kgsw+DJKq0LsvxejQOPTajh6zrG90DpA9EQ0RVdKIP7h7cZ3UXAOgNycSqrnJ tPbDwyldcWKsLH9w5HGRVvMWq/78FFfIg7g9nFhTLjIXOafVpxWDw2U54l3oZoy1B9zYvx VyAV7j9n8xo3o08As3ERBzoJipB8VcI= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1648581230; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=8vITF4y5I3Qh2gV4oA1G6ENMes/c4yf/oaIqSyELU/A=; b=TqVsSeCz/588wD5Fm9vxZ4m41p58zhiATVblsqqooXov50DRQ0dIpT9mwtOqVZ15qVmmOK vfe9GHN0kqOBkbAQ== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 66A3313A7E; Tue, 29 Mar 2022 19:13:49 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id t7ScFW1aQ2IOVQAAMHmgww (envelope-from ); Tue, 29 Mar 2022 19:13:49 +0000 Date: Tue, 29 Mar 2022 21:13:47 +0200 From: Oscar Salvador To: Rik van Riel Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, kernel-team@fb.com, Miaohe Lin , Naoya Horiguchi , Mel Gorman , Johannes Weiner , Andrew Morton , stable@vger.kernel.org Subject: Re: [PATCH] mm,hwpoison: unmap poisoned page before invalidation Message-ID: References: <20220325161428.5068d97e@imladris.surriel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220325161428.5068d97e@imladris.surriel.com> X-Stat-Signature: bgkaha6jm6dkexgmfhrxj574xcxqbwrg X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: 49B781C000C Authentication-Results: imf21.hostedemail.com; dkim=pass header.d=suse.de header.s=susede2_rsa header.b=ck65D7u9; dkim=pass header.d=suse.de header.s=susede2_ed25519 header.b=TqVsSeCz; dmarc=pass (policy=none) header.from=suse.de; spf=pass (imf21.hostedemail.com: domain of osalvador@suse.de designates 195.135.220.28 as permitted sender) smtp.mailfrom=osalvador@suse.de X-Rspam-User: X-HE-Tag: 1648581231-639217 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: On Fri, Mar 25, 2022 at 04:14:28PM -0400, Rik van Riel wrote: > In some cases it appears the invalidation of a hwpoisoned page > fails because the page is still mapped in another process. This > can cause a program to be continuously restarted and die when > it page faults on the page that was not invalidated. Avoid that > problem by unmapping the hwpoisoned page when we find it. > > Another issue is that sometimes we end up oopsing in finish_fault, > if the code tries to do something with the now-NULL vmf->page. > I did not hit this error when submitting the previous patch because > there are several opportunities for alloc_set_pte to bail out before > accessing vmf->page, and that apparently happened on those systems, > and most of the time on other systems, too. > > However, across several million systems that error does occur a > handful of times a day. It can be avoided by returning VM_FAULT_NOPAGE > which will cause do_read_fault to return before calling finish_fault. > > Fixes: e53ac7374e64 ("mm: invalidate hwpoison page cache page in fault path") > Cc: Oscar Salvador > Cc: Miaohe Lin > Cc: Naoya Horiguchi > Cc: Mel Gorman > Cc: Johannes Weiner > Cc: Andrew Morton > Cc: stable@vger.kernel.org Reviewed-by: Oscar Salvador > --- > mm/memory.c | 12 ++++++++---- > 1 file changed, 8 insertions(+), 4 deletions(-) > > diff --git a/mm/memory.c b/mm/memory.c > index be44d0b36b18..76e3af9639d9 100644 > --- a/mm/memory.c > +++ b/mm/memory.c > @@ -3918,14 +3918,18 @@ static vm_fault_t __do_fault(struct vm_fault *vmf) > return ret; > > if (unlikely(PageHWPoison(vmf->page))) { > + struct page *page = vmf->page; > vm_fault_t poisonret = VM_FAULT_HWPOISON; > if (ret & VM_FAULT_LOCKED) { > + if (page_mapped(page)) > + unmap_mapping_pages(page_mapping(page), > + page->index, 1, false); > /* Retry if a clean page was removed from the cache. */ > - if (invalidate_inode_page(vmf->page)) > - poisonret = 0; > - unlock_page(vmf->page); > + if (invalidate_inode_page(page)) > + poisonret = VM_FAULT_NOPAGE; > + unlock_page(page); > } > - put_page(vmf->page); > + put_page(page); > vmf->page = NULL; > return poisonret; > } > -- > 2.35.1 > > > -- Oscar Salvador SUSE Labs