From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Pavel Tatashin , Michal Hocko , Andrew Morton , Vlastimil Babka , Steven Sistare , Daniel Jordan , "Kirill A. Shutemov" , Linus Torvalds Subject: [PATCH 4.14 31/62] mm: sections are not offlined during memory hotremove Date: Mon, 14 May 2018 08:48:47 +0200 Message-Id: <20180514064818.091284600@linuxfoundation.org> In-Reply-To: <20180514064816.436958006@linuxfoundation.org> References: <20180514064816.436958006@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Pavel Tatashin commit 27227c733852f71008e9bf165950bb2edaed3a90 upstream. Memory hotplug and hotremove operate with per-block granularity. If the machine has a large amount of memory (more than 64G), the size of a memory block can span multiple sections. By mistake, during hotremove we set only the first section to offline state. The bug was discovered because kernel selftest started to fail: https://lkml.kernel.org/r/20180423011247.GK5563@yexl-desktop After commit, "mm/memory_hotplug: optimize probe routine". But, the bug is older than this commit. In this optimization we also added a check for sections to be in a proper state during hotplug operation. Link: http://lkml.kernel.org/r/20180427145257.15222-1-pasha.tatashin@oracle.com Fixes: 2d070eab2e82 ("mm: consider zone which is not fully populated to have holes") Signed-off-by: Pavel Tatashin Acked-by: Michal Hocko Reviewed-by: Andrew Morton Cc: Vlastimil Babka Cc: Steven Sistare Cc: Daniel Jordan Cc: "Kirill A. Shutemov" Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/sparse.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/sparse.c +++ b/mm/sparse.c @@ -661,7 +661,7 @@ void offline_mem_sections(unsigned long unsigned long pfn; for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) { - unsigned long section_nr = pfn_to_section_nr(start_pfn); + unsigned long section_nr = pfn_to_section_nr(pfn); struct mem_section *ms; /*