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=-8.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT 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 3AB98C43613 for ; Thu, 20 Jun 2019 16:08:26 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 06E652084E for ; Thu, 20 Jun 2019 16:08:25 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 06E652084E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 973968E0002; Thu, 20 Jun 2019 12:08:25 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 9249A8E0001; Thu, 20 Jun 2019 12:08:25 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 812948E0002; Thu, 20 Jun 2019 12:08:25 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from mail-ed1-f70.google.com (mail-ed1-f70.google.com [209.85.208.70]) by kanga.kvack.org (Postfix) with ESMTP id 47CC28E0001 for ; Thu, 20 Jun 2019 12:08:25 -0400 (EDT) Received: by mail-ed1-f70.google.com with SMTP id i9so4891465edr.13 for ; Thu, 20 Jun 2019 09:08:25 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-original-authentication-results:x-gm-message-state:from:to:cc :subject:date:message-id; bh=Wj4l7u5/Zr5Kx/uUEp0mWbD594cR9O6KElaUEAz2BSY=; b=KFIgMKgoLhaQQjNbzapHQ5ZzqNkcyb/SEMH8f4J/r+ehHotnhZ3HljxOhUCZKoioks nfVLqw84TZsjkpoHV4E3MihJtzCG6vjvTgjXJGdO3gUwSoaULn563+31IaxVRyYBKuUJ awi4xaCTlkFiO0vnq0VxMfUBz8DJc0DQgVzVynqwq0NvCCdlGW1f0f6ln4pGCZLDcipW vQ+61QKPdHY6r3uZ6y/nlkaYtMQFdz4nt9gBiptkzIUcEyf/vsFjdmvKbxeKMCDw/a/c 2598ByQorGgtb6idtxXOVDZM2lF21vB/YFkVOalozkfGzLHBBp8TiScU8EuC/rz2uk0R CUig== X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of jgross@suse.com designates 195.135.220.15 as permitted sender) smtp.mailfrom=jgross@suse.com X-Gm-Message-State: APjAAAWyujq5z9HY09AjdLuLCrcbXiBITas0kSTio4kRFZHMEVXt9QV7 OjIz0sa4FvU6VcwYZlbi1QHHkxu5T3oMNs5w/Ae8PLA+NtCj2I4ejgD5r3e0oKrJAapFszaH0tu fAOiXMJz1yAAL5UD1tsXVTyA/jKkwQyDzhJAtCk4Fne4zw2JVRFMgrUX+dmq7hkiVqA== X-Received: by 2002:a17:906:45d7:: with SMTP id z23mr60665389ejq.54.1561046904824; Thu, 20 Jun 2019 09:08:24 -0700 (PDT) X-Google-Smtp-Source: APXvYqxIFZYXFM5jxpKpM12w8FYZpRJsDEFYLu02dwjiwp3ph6dqboBevAvolbRl6e9NawCOcXHb X-Received: by 2002:a17:906:45d7:: with SMTP id z23mr60665319ejq.54.1561046904040; Thu, 20 Jun 2019 09:08:24 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1561046904; cv=none; d=google.com; s=arc-20160816; b=N7QWZWy6bAjwK6Pikmik08Xccf1JOlkEf+K0/u9PKTozWQRRf/OYmxk1DRPXuiIEkv /D346yk8jF0FjKnsZrZ54FZNBYjiF2zSeeapW1BvKDxtmnVw7skyUrnQSL1WMvGRpslB LAZSg/k+FGGwM0BrdR5EoyCH+bF39C3hJPBY0FGuFtaFSvGJPVJSoAYyYEYppppLmJPJ v99wjQ5fb7gQgQn4wCfgapnBPhONMzh08aORh71hnE1c/Jrjdmcitgk13qKv0PMqYy1q iooPmtdFvLCF3nhAb7hrDe+0o0EYa08AZ8+lfNscGroo8A4MkrxJmdSFT5n2FS493d41 q4KQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=message-id:date:subject:cc:to:from; bh=Wj4l7u5/Zr5Kx/uUEp0mWbD594cR9O6KElaUEAz2BSY=; b=hZAxPMiJT01mzh2F6NHzGjRdL0W8B9i/SHlUi/3BqA4qLwIxCzFhkersVeASKzVwTd xlyRWrtJCjfNILL2FZtoErMtUHYpghpKmprNT7R0oyJOjAjSxx3pfzxNyarU4+2BYPLT oebvGJ2r5QAqmQDMto00Q0aPeXuu0EfzZd1FlXJ1luzEhFdVUvjhpkoyGUrozE4i750C i9jGfgC6k2trMaMByvl6jMW5UBDGf06MOBDcx4zTSnUYEJMkWXS3s5HqtJ3sPnkER8hD Y95/vS9N8bFfjfxNpc2keWKWNGlnTHE7OYHCIZEdPXg3kRuxOgnKjWvrhbkchIOdbi3Z qVlw== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of jgross@suse.com designates 195.135.220.15 as permitted sender) smtp.mailfrom=jgross@suse.com Received: from mx1.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id p2si209097edh.167.2019.06.20.09.08.23 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 20 Jun 2019 09:08:24 -0700 (PDT) Received-SPF: pass (google.com: domain of jgross@suse.com designates 195.135.220.15 as permitted sender) client-ip=195.135.220.15; Authentication-Results: mx.google.com; spf=pass (google.com: domain of jgross@suse.com designates 195.135.220.15 as permitted sender) smtp.mailfrom=jgross@suse.com X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 979FEAF2B; Thu, 20 Jun 2019 16:08:23 +0000 (UTC) From: Juergen Gross To: xen-devel@lists.xenproject.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: Juergen Gross , Alexander Duyck Subject: [PATCH] mm: fix regression with deferred struct page init Date: Thu, 20 Jun 2019 18:08:21 +0200 Message-Id: <20190620160821.4210-1-jgross@suse.com> X-Mailer: git-send-email 2.16.4 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: Commit 0e56acae4b4dd4a9 ("mm: initialize MAX_ORDER_NR_PAGES at a time instead of doing larger sections") is causing a regression on some systems when the kernel is booted as Xen dom0. The system will just hang in early boot. Reason is an endless loop in get_page_from_freelist() in case the first zone looked at has no free memory. deferred_grow_zone() is always returning true due to the following code snipplet: /* If the zone is empty somebody else may have cleared out the zone */ if (!deferred_init_mem_pfn_range_in_zone(&i, zone, &spfn, &epfn, first_deferred_pfn)) { pgdat->first_deferred_pfn = ULONG_MAX; pgdat_resize_unlock(pgdat, &flags); return true; } This in turn results in the loop as get_page_from_freelist() is assuming forward progress can be made by doing some more struct page initialization. Cc: Alexander Duyck Fixes: 0e56acae4b4dd4a9 ("mm: initialize MAX_ORDER_NR_PAGES at a time instead of doing larger sections") Suggested-by: Alexander Duyck Signed-off-by: Juergen Gross --- mm/page_alloc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index d66bc8abe0af..8e3bc949ebcc 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1826,7 +1826,8 @@ deferred_grow_zone(struct zone *zone, unsigned int order) first_deferred_pfn)) { pgdat->first_deferred_pfn = ULONG_MAX; pgdat_resize_unlock(pgdat, &flags); - return true; + /* Retry only once. */ + return first_deferred_pfn != ULONG_MAX; } /* -- 2.16.4