From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx163.postini.com [74.125.245.163]) by kanga.kvack.org (Postfix) with SMTP id 46B9F6B0002 for ; Wed, 22 May 2013 19:39:07 -0400 (EDT) Received: from /spool/local by e23smtp06.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 23 May 2013 09:32:31 +1000 Received: from d23relay05.au.ibm.com (d23relay05.au.ibm.com [9.190.235.152]) by d23dlp02.au.ibm.com (Postfix) with ESMTP id BC7852BB0051 for ; Thu, 23 May 2013 09:38:57 +1000 (EST) Received: from d23av02.au.ibm.com (d23av02.au.ibm.com [9.190.235.138]) by d23relay05.au.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r4MNOdWk11534390 for ; Thu, 23 May 2013 09:24:39 +1000 Received: from d23av02.au.ibm.com (loopback [127.0.0.1]) by d23av02.au.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r4MNctF8004129 for ; Thu, 23 May 2013 09:38:56 +1000 Date: Thu, 23 May 2013 07:38:54 +0800 From: Wanpeng Li Subject: Re: [PATCH 1/4] mm/memory-hotplug: fix lowmem count overflow when offline pages Message-ID: <20130522233854.GA13972@hacker.(null)> Reply-To: Wanpeng Li References: <1369214970-1526-1-git-send-email-liwanp@linux.vnet.ibm.com> <20130522104937.GC19989@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130522104937.GC19989@dhcp22.suse.cz> Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: Andrew Morton , KAMEZAWA Hiroyuki , David Rientjes , Jiang Liu , Tang Chen , linux-mm@kvack.org, linux-kernel@vger.kernel.org On Wed, May 22, 2013 at 12:49:37PM +0200, Michal Hocko wrote: >On Wed 22-05-13 17:29:27, Wanpeng Li wrote: >> Logic memory-remove code fails to correctly account the Total High Memory >> when a memory block which contains High Memory is offlined as shown in the >> example below. The following patch fixes it. >> >> cat /proc/meminfo >> MemTotal: 7079452 kB >> MemFree: 5805976 kB >> Buffers: 94372 kB >> Cached: 872000 kB >> SwapCached: 0 kB >> Active: 626936 kB >> Inactive: 519236 kB >> Active(anon): 180780 kB >> Inactive(anon): 222944 kB >> Active(file): 446156 kB >> Inactive(file): 296292 kB >> Unevictable: 0 kB >> Mlocked: 0 kB >> HighTotal: 7294672 kB >> HighFree: 5181024 kB >> LowTotal: 4294752076 kB >> LowFree: 624952 kB > >Ok, so the HighTotal is higher than MemTotal but it would have been more >straightforward to show number of HighTotal before hotremove, show how >much memory has been removed and the number after. > >It is not clear which stable kernels need this fix as well. > THanks for your review, Michal, I will update soon. ;-) >> >> Signed-off-by: Wanpeng Li > >Anyway >Reviewed-by: Michal Hocko > >with a nit pick bellow > >> --- >> mm/page_alloc.c | 4 ++++ >> 1 file changed, 4 insertions(+) >> >> diff --git a/mm/page_alloc.c b/mm/page_alloc.c >> index 98cbdf6..80474b2 100644 >> --- a/mm/page_alloc.c >> +++ b/mm/page_alloc.c >> @@ -6140,6 +6140,10 @@ __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn) >> list_del(&page->lru); >> rmv_page_order(page); >> zone->free_area[order].nr_free--; >> +#ifdef CONFIG_HIGHMEM >> + if (PageHighMem(page)) >> + totalhigh_pages -= 1 << order; >> +#endif > >ifdef shouldn't be necessary as PageHighMem should default to false for >!CONFIG_HIGHMEM AFAICS. > >> for (i = 0; i < (1 << order); i++) >> SetPageReserved((page+i)); >> pfn += (1 << order); >> -- >> 1.8.1.2 >> >> -- >> 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 > >-- >Michal Hocko >SUSE Labs -- 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