From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk1-f198.google.com (mail-qk1-f198.google.com [209.85.222.198]) by kanga.kvack.org (Postfix) with ESMTP id 08D428E0001 for ; Fri, 28 Sep 2018 11:36:22 -0400 (EDT) Received: by mail-qk1-f198.google.com with SMTP id q20-v6so6286603qke.21 for ; Fri, 28 Sep 2018 08:36:22 -0700 (PDT) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id x25-v6sor2067082qtb.92.2018.09.28.08.36.21 for (Google Transport Security); Fri, 28 Sep 2018 08:36:21 -0700 (PDT) Date: Fri, 28 Sep 2018 11:36:18 -0400 From: Masayoshi Mizuma Subject: Re: [PATCH v2 3/3] mm: return zero_resv_unavail optimization Message-ID: <20180928153618.gdxyb337a4w32vit@gabell> References: <20180925153532.6206-1-msys.mizuma@gmail.com> <20180925153532.6206-4-msys.mizuma@gmail.com> <20180928001944.GA9242@hori1.linux.bs1.fc.nec.co.jp> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180928001944.GA9242@hori1.linux.bs1.fc.nec.co.jp> Sender: owner-linux-mm@kvack.org List-ID: To: Naoya Horiguchi Cc: "linux-mm@kvack.org" , Pavel Tatashin , Michal Hocko , "linux-kernel@vger.kernel.org" , "x86@kernel.org" On Fri, Sep 28, 2018 at 12:19:44AM +0000, Naoya Horiguchi wrote: > On Tue, Sep 25, 2018 at 11:35:32AM -0400, Masayoshi Mizuma wrote: > > From: Pavel Tatashin > > > > When checking for valid pfns in zero_resv_unavail(), it is not necessary to > > verify that pfns within pageblock_nr_pages ranges are valid, only the first > > one needs to be checked. This is because memory for pages are allocated in > > contiguous chunks that contain pageblock_nr_pages struct pages. > > > > Signed-off-by: Pavel Tatashin > > Reviewed-off-by: Masayoshi Mizuma > > According to convention, review tag is formatted like "Reviewed-by: ...", Sorry for the typo... > Otherwise, looks good to me. > > Acked-by: Naoya Horiguchi Thanks! - Masa > > > --- > > mm/page_alloc.c | 46 ++++++++++++++++++++++++++-------------------- > > 1 file changed, 26 insertions(+), 20 deletions(-) > > > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > > index 3b9d89e..bd5b7e4 100644 > > --- a/mm/page_alloc.c > > +++ b/mm/page_alloc.c > > @@ -6440,6 +6440,29 @@ void __init free_area_init_node(int nid, unsigned long *zones_size, > > } > > > > #if defined(CONFIG_HAVE_MEMBLOCK) && !defined(CONFIG_FLAT_NODE_MEM_MAP) > > + > > +/* > > + * Zero all valid struct pages in range [spfn, epfn), return number of struct > > + * pages zeroed > > + */ > > +static u64 zero_pfn_range(unsigned long spfn, unsigned long epfn) > > +{ > > + unsigned long pfn; > > + u64 pgcnt = 0; > > + > > + for (pfn = spfn; pfn < epfn; pfn++) { > > + if (!pfn_valid(ALIGN_DOWN(pfn, pageblock_nr_pages))) { > > + pfn = ALIGN_DOWN(pfn, pageblock_nr_pages) > > + + pageblock_nr_pages - 1; > > + continue; > > + } > > + mm_zero_struct_page(pfn_to_page(pfn)); > > + pgcnt++; > > + } > > + > > + return pgcnt; > > +} > > + > > /* > > * Only struct pages that are backed by physical memory are zeroed and > > * initialized by going through __init_single_page(). But, there are some > > @@ -6455,7 +6478,6 @@ void __init free_area_init_node(int nid, unsigned long *zones_size, > > void __init zero_resv_unavail(void) > > { > > phys_addr_t start, end; > > - unsigned long pfn; > > u64 i, pgcnt; > > phys_addr_t next = 0; > > > > @@ -6465,34 +6487,18 @@ void __init zero_resv_unavail(void) > > pgcnt = 0; > > for_each_mem_range(i, &memblock.memory, NULL, > > NUMA_NO_NODE, MEMBLOCK_NONE, &start, &end, NULL) { > > - if (next < start) { > > - for (pfn = PFN_DOWN(next); pfn < PFN_UP(start); pfn++) { > > - if (!pfn_valid(ALIGN_DOWN(pfn, pageblock_nr_pages))) > > - continue; > > - mm_zero_struct_page(pfn_to_page(pfn)); > > - pgcnt++; > > - } > > - } > > + if (next < start) > > + pgcnt += zero_pfn_range(PFN_DOWN(next), PFN_UP(start)); > > next = end; > > } > > - for (pfn = PFN_DOWN(next); pfn < max_pfn; pfn++) { > > - if (!pfn_valid(ALIGN_DOWN(pfn, pageblock_nr_pages))) > > - continue; > > - mm_zero_struct_page(pfn_to_page(pfn)); > > - pgcnt++; > > - } > > - > > + pgcnt += zero_pfn_range(PFN_DOWN(next), max_pfn); > > > > /* > > * Struct pages that do not have backing memory. This could be because > > * firmware is using some of this memory, or for some other reasons. > > - * Once memblock is changed so such behaviour is not allowed: i.e. > > - * list of "reserved" memory must be a subset of list of "memory", then > > - * this code can be removed. > > */ > > if (pgcnt) > > pr_info("Zeroed struct page in unavailable ranges: %lld pages", pgcnt); > > - > > } > > #endif /* CONFIG_HAVE_MEMBLOCK && !CONFIG_FLAT_NODE_MEM_MAP */ > > > > -- > > 2.18.0 > > > >