From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr0-f199.google.com (mail-wr0-f199.google.com [209.85.128.199]) by kanga.kvack.org (Postfix) with ESMTP id 248CD6B0006 for ; Mon, 19 Feb 2018 08:56:51 -0500 (EST) Received: by mail-wr0-f199.google.com with SMTP id h13so6024404wrc.9 for ; Mon, 19 Feb 2018 05:56:51 -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 k26sor8317358edk.34.2018.02.19.05.56.49 for (Google Transport Security); Mon, 19 Feb 2018 05:56:49 -0800 (PST) Date: Mon, 19 Feb 2018 16:56:46 +0300 From: "Kirill A. Shutemov" Subject: Re: [mainline][Memory off/on][83e3c48] kernel Oops with memory hot-unplug on ppc Message-ID: <20180219135646.lsmxkbgdwrjdlwxy@node.shutemov.name> References: <1517840664.647.17.camel@abdul.in.ibm.com> <20180219134735.GN21134@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180219134735.GN21134@dhcp22.suse.cz> Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: Abdul Haleem , linuxppc-dev , linux-mm@kvack.org, kirill.shutemov@linux.intel.com, mpe , Stephen Rothwell , linux-kernel , sachinp On Mon, Feb 19, 2018 at 02:47:35PM +0100, Michal Hocko wrote: > [CC Kirill - I have a vague recollection that there were some follow ups > for 83e3c48729d9 ("mm/sparsemem: Allocate mem_section at runtime for > CONFIG_SPARSEMEM_EXTREME=y"). Does any of them apply to this issue?] All fixups are in v4.15. > On Mon 05-02-18 19:54:24, Abdul Haleem wrote: > > > > Greetings, > > > > Kernel Oops seen when memory hot-unplug on powerpc mainline kernel. > > > > Machine: Power6 PowerVM ppc64 > > Kernel: 4.15.0 > > Config: attached > > gcc: 4.8.2 > > Test: Memory hot-unplug of a memory block > > echo offline > /sys/devices/system/memory/memory/state > > > > The faulty instruction address points to the code path: > > > > # gdb -batch vmlinux -ex 'list *(0xc000000000238330)' > > 0xc000000000238330 is in get_pfnblock_flags_mask > > (./include/linux/mmzone.h:1157). > > 1152 #endif > > 1153 > > 1154 static inline struct mem_section *__nr_to_section(unsigned long nr) > > 1155 { > > 1156 #ifdef CONFIG_SPARSEMEM_EXTREME > > 1157 if (!mem_section) > > 1158 return NULL; > > 1159 #endif > > 1160 if (!mem_section[SECTION_NR_TO_ROOT(nr)]) > > 1161 return NULL; > > > > > > The code was first introduced with commit( 83e3c48: mm/sparsemem: > > Allocate mem_section at runtime for CONFIG_SPARSEMEM_EXTREME=y) Any chance to bisect it? Could you check if the commit just before 83e3c48729d9 is fine? -- Kirill A. Shutemov -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org