Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756045Ab3GYNwU (ORCPT ); Thu, 25 Jul 2013 09:52:20 -0400 Received: from mail-ob0-f171.google.com ([209.85.214.171]:36227 "EHLO mail-ob0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755882Ab3GYNwQ (ORCPT ); Thu, 25 Jul 2013 09:52:16 -0400 MIME-Version: 1.0 In-Reply-To: <20130725134227.GT3421@sgi.com> References: <1373594635-131067-1-git-send-email-holt@sgi.com> <1373594635-131067-5-git-send-email-holt@sgi.com> <20130725022543.GR3421@sgi.com> <20130725134227.GT3421@sgi.com> Date: Thu, 25 Jul 2013 06:52:15 -0700 X-Google-Sender-Auth: wod5VkvBGZqQik8bN-EHGy2apic Message-ID: Subject: Re: [RFC 4/4] Sparse initialization of struct page array. From: Yinghai Lu To: Robin Holt Cc: "H. Peter Anvin" , Ingo Molnar , Nate Zimmer , Linux Kernel , Linux MM , Rob Landley , Mike Travis , Daniel J Blueman , Andrew Morton , Greg KH , Mel Gorman Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5674 Lines: 146 On Thu, Jul 25, 2013 at 6:42 AM, Robin Holt wrote: > On Thu, Jul 25, 2013 at 05:50:57AM -0700, Yinghai Lu wrote: >> On Wed, Jul 24, 2013 at 7:25 PM, Robin Holt wrote: >> >> >> >> How about holes that is not in memblock.reserved? >> >> >> >> before this patch: >> >> free_area_init_node/free_area_init_core/memmap_init_zone >> >> will mark all page in node range to Reserved in struct page, at first. >> >> >> >> but those holes is not mapped via kernel low mapping. >> >> so it should be ok not touch "struct page" for them. >> >> >> >> Now you only mark reserved for memblock.reserved at first, and later >> >> mark {memblock.memory} - { memblock.reserved} to be available. >> >> And that is ok. >> >> >> >> but should split that change to another patch and add some comment >> >> and change log for the change. >> >> in case there is some user like UEFI etc do weird thing. >> > >> > Nate and I talked this over today. Sorry for the delay, but it was the >> > first time we were both free. Neither of us quite understands what you >> > are asking for here. My interpretation is that you would like us to >> > change the use of the PageReserved flag such that during boot, we do not >> > set the flag at all from memmap_init_zone, and then only set it on pages >> > which, at the time of free_all_bootmem, have been allocated/reserved in >> > the memblock allocator. Is that correct? I will start to work that up >> > on the assumption that is what you are asking for. >> >> Not exactly. >> >> your change should be right, but there is some subtle change about >> holes handling. >> >> before mem holes between memory ranges in memblock.memory, get struct page, >> and initialized with to Reserved in memmap_init_zone. >> Those holes is not in memory.reserved, with your patches, those hole's >> struct page >> will still have all 0. >> >> Please separate change about set page to reserved according to memory.reserved >> to another patch. > > > Just want to make sure this is where you want me to go. Here is my > currently untested patch. Is that what you were expecting to have done? > One thing I don't like about this patch is it seems to slow down boot in > my simulator environment. I think I am going to look at restructuring > things a bit to see if I can eliminate that performance penalty. > Otherwise, I think I am following your directions. > > From bdd2fefa59af18f283af6f066bc644ddfa5c7da8 Mon Sep 17 00:00:00 2001 > From: Robin Holt > Date: Thu, 25 Jul 2013 04:25:15 -0500 > Subject: [RFC -v2-pre2 4/5] ZZZ Only SegPageReserved() on memblock reserved > pages. yes. > > --- > include/linux/mm.h | 2 ++ > mm/nobootmem.c | 3 +++ > mm/page_alloc.c | 18 +++++++++++------- > 3 files changed, 16 insertions(+), 7 deletions(-) > > diff --git a/include/linux/mm.h b/include/linux/mm.h > index e0c8528..b264a26 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -1322,6 +1322,8 @@ static inline void adjust_managed_page_count(struct page *page, long count) > totalram_pages += count; > } > > +extern void reserve_bootmem_region(unsigned long start, unsigned long end); > + > /* Free the reserved page into the buddy system, so it gets managed. */ > static inline void __free_reserved_page(struct page *page) > { > diff --git a/mm/nobootmem.c b/mm/nobootmem.c > index 2159e68..0840af2 100644 > --- a/mm/nobootmem.c > +++ b/mm/nobootmem.c > @@ -117,6 +117,9 @@ static unsigned long __init free_low_memory_core_early(void) > phys_addr_t start, end, size; > u64 i; > > + for_each_reserved_mem_region(i, &start, &end) > + reserve_bootmem_region(start, end); > + > for_each_free_mem_range(i, MAX_NUMNODES, &start, &end, NULL) > count += __free_memory_core(start, end); > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index 048e166..3aa30b7 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -698,7 +698,7 @@ static void free_one_page(struct zone *zone, struct page *page, int order, > } > > static void __init_single_page(unsigned long pfn, unsigned long zone, > - int nid, int reserved) > + int nid, int page_count) > { > struct page *page = pfn_to_page(pfn); > struct zone *z = &NODE_DATA(nid)->node_zones[zone]; > @@ -708,12 +708,9 @@ static void __init_single_page(unsigned long pfn, unsigned long zone, > init_page_count(page); > page_mapcount_reset(page); > page_nid_reset_last(page); > - if (reserved) { > - SetPageReserved(page); > - } else { > - ClearPageReserved(page); > - set_page_count(page, 0); > - } > + ClearPageReserved(page); > + set_page_count(page, page_count); > + > /* > * Mark the block movable so that blocks are reserved for > * movable at startup. This will force kernel allocations > @@ -741,6 +738,13 @@ static void __init_single_page(unsigned long pfn, unsigned long zone, > #endif > } > > +void reserve_bootmem_region(unsigned long start, unsigned long end) > +{ > + for (; start < end; start++) > + if (pfn_valid(start)) > + SetPageReserved(pfn_to_page(start)); > +} > + > static bool free_pages_prepare(struct page *page, unsigned int order) > { > int i; > -- > 1.8.2.1 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/