From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michal Hocko Date: Mon, 01 Jul 2019 07:45:03 +0000 Subject: Re: [PATCH v3 03/11] s390x/mm: Implement arch_remove_memory() Message-Id: <20190701074503.GD6376@dhcp22.suse.cz> List-Id: References: <20190527111152.16324-1-david@redhat.com> <20190527111152.16324-4-david@redhat.com> In-Reply-To: <20190527111152.16324-4-david@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: David Hildenbrand Cc: Oscar Salvador , linux-s390@vger.kernel.org, linux-ia64@vger.kernel.org, Vasily Gorbik , linux-sh@vger.kernel.org, Heiko Carstens , linux-kernel@vger.kernel.org, Wei Yang , linux-mm@kvack.org, Mike Rapoport , Martin Schwidefsky , Igor Mammedov , akpm@linux-foundation.org, linuxppc-dev@lists.ozlabs.org, Dan Williams , linux-arm-kernel@lists.infradead.org On Mon 27-05-19 13:11:44, David Hildenbrand wrote: > Will come in handy when wanting to handle errors after > arch_add_memory(). I do not understand this. Why do you add a code for something that is not possible on this HW (based on the comment - is it still valid btw?) > Cc: Martin Schwidefsky > Cc: Heiko Carstens > Cc: Andrew Morton > Cc: Michal Hocko > Cc: Mike Rapoport > Cc: David Hildenbrand > Cc: Vasily Gorbik > Cc: Oscar Salvador > Signed-off-by: David Hildenbrand > --- > arch/s390/mm/init.c | 13 +++++++------ > 1 file changed, 7 insertions(+), 6 deletions(-) > > diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c > index d552e330fbcc..14955e0a9fcf 100644 > --- a/arch/s390/mm/init.c > +++ b/arch/s390/mm/init.c > @@ -243,12 +243,13 @@ int arch_add_memory(int nid, u64 start, u64 size, > void arch_remove_memory(int nid, u64 start, u64 size, > struct vmem_altmap *altmap) > { > - /* > - * There is no hardware or firmware interface which could trigger a > - * hot memory remove on s390. So there is nothing that needs to be > - * implemented. > - */ > - BUG(); > + unsigned long start_pfn = start >> PAGE_SHIFT; > + unsigned long nr_pages = size >> PAGE_SHIFT; > + struct zone *zone; > + > + zone = page_zone(pfn_to_page(start_pfn)); > + __remove_pages(zone, start_pfn, nr_pages, altmap); > + vmem_remove_mapping(start, size); > } > #endif > #endif /* CONFIG_MEMORY_HOTPLUG */ > -- > 2.20.1 > -- Michal Hocko SUSE Labs