Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754613AbdDEIOf (ORCPT ); Wed, 5 Apr 2017 04:14:35 -0400 Received: from mx2.suse.de ([195.135.220.15]:53919 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753183AbdDEIOF (ORCPT ); Wed, 5 Apr 2017 04:14:05 -0400 Date: Wed, 5 Apr 2017 10:14:00 +0200 From: Michal Hocko To: linux-mm@kvack.org Cc: Andrew Morton , Mel Gorman , Vlastimil Babka , Andrea Arcangeli , Reza Arbab , Yasuaki Ishimatsu , Tang Chen , qiuxishi@huawei.com, Kani Toshimitsu , slaoub@gmail.com, Joonsoo Kim , Andi Kleen , David Rientjes , Daniel Kiper , Igor Mammedov , Vitaly Kuznetsov , LKML Subject: Re: [PATCH v1 1/6] mm: get rid of zone_is_initialized Message-ID: <20170405081400.GE6035@dhcp22.suse.cz> References: <20170330115454.32154-1-mhocko@kernel.org> <20170330115454.32154-2-mhocko@kernel.org> <20170331073954.GF27098@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170331073954.GF27098@dhcp22.suse.cz> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3917 Lines: 116 On Fri 31-03-17 09:39:54, Michal Hocko wrote: > Fixed screw ups during the initial patch split up as per Hillf > --- > From 8be6c5e47de66210e47710c80e72e8abd899017b Mon Sep 17 00:00:00 2001 > From: Michal Hocko > Date: Wed, 29 Mar 2017 15:11:30 +0200 > Subject: [PATCH] mm: get rid of zone_is_initialized > > There shouldn't be any reason to add initialized when we can tell the > same thing from checking whether there are any pages spanned to the > zone. Remove zone_is_initialized() and replace it by zone_is_empty > which can be used for the same set of tests. > > This shouldn't have any visible effect I've decided to drop this patch. My main motivation was to simplify the hotplug workflow/ The situation is more hairy than I expected, though. On one hand all zones should be initialized early during the hotplug in add_memory_resource but direct users of arch_add_memory will need this to be called I suspect. Let's just keep the current status quo and clean up it later. It is not really needed for this series. > Signed-off-by: Michal Hocko > --- > include/linux/mmzone.h | 7 ------- > mm/memory_hotplug.c | 6 +++--- > mm/page_alloc.c | 3 +-- > 3 files changed, 4 insertions(+), 12 deletions(-) > > diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h > index 618499159a7c..3bac3ed71c7a 100644 > --- a/include/linux/mmzone.h > +++ b/include/linux/mmzone.h > @@ -442,8 +442,6 @@ struct zone { > seqlock_t span_seqlock; > #endif > > - int initialized; > - > /* Write-intensive fields used from the page allocator */ > ZONE_PADDING(_pad1_) > > @@ -520,11 +518,6 @@ static inline bool zone_spans_pfn(const struct zone *zone, unsigned long pfn) > return zone->zone_start_pfn <= pfn && pfn < zone_end_pfn(zone); > } > > -static inline bool zone_is_initialized(struct zone *zone) > -{ > - return zone->initialized; > -} > - > static inline bool zone_is_empty(struct zone *zone) > { > return zone->spanned_pages == 0; > diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c > index 6fb6bd2df787..699f5a2a8efd 100644 > --- a/mm/memory_hotplug.c > +++ b/mm/memory_hotplug.c > @@ -348,7 +348,7 @@ static void fix_zone_id(struct zone *zone, unsigned long start_pfn, > static int __ref ensure_zone_is_initialized(struct zone *zone, > unsigned long start_pfn, unsigned long num_pages) > { > - if (!zone_is_initialized(zone)) > + if (zone_is_empty(zone)) > return init_currently_empty_zone(zone, start_pfn, num_pages); > > return 0; > @@ -1051,7 +1051,7 @@ bool zone_can_shift(unsigned long pfn, unsigned long nr_pages, > > /* no zones in use between current zone and target */ > for (i = idx + 1; i < target; i++) > - if (zone_is_initialized(zone - idx + i)) > + if (!zone_is_empty(zone - idx + i)) > return false; > } > > @@ -1062,7 +1062,7 @@ bool zone_can_shift(unsigned long pfn, unsigned long nr_pages, > > /* no zones in use between current zone and target */ > for (i = target + 1; i < idx; i++) > - if (zone_is_initialized(zone - idx + i)) > + if (!zone_is_empty(zone - idx + i)) > return false; > } > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index 5ee8a26fa383..756353d1e293 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -795,7 +795,7 @@ static inline void __free_one_page(struct page *page, > > max_order = min_t(unsigned int, MAX_ORDER, pageblock_order + 1); > > - VM_BUG_ON(!zone_is_initialized(zone)); > + VM_BUG_ON(zone_is_empty(zone)); > VM_BUG_ON_PAGE(page->flags & PAGE_FLAGS_CHECK_AT_PREP, page); > > VM_BUG_ON(migratetype == -1); > @@ -5535,7 +5535,6 @@ int __meminit init_currently_empty_zone(struct zone *zone, > zone_start_pfn, (zone_start_pfn + size)); > > zone_init_free_lists(zone); > - zone->initialized = 1; > > return 0; > } > -- > 2.11.0 > > -- > Michal Hocko > SUSE Labs -- Michal Hocko SUSE Labs