From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f199.google.com (mail-pf0-f199.google.com [209.85.192.199]) by kanga.kvack.org (Postfix) with ESMTP id 52C236B0038 for ; Tue, 3 Oct 2017 09:09:01 -0400 (EDT) Received: by mail-pf0-f199.google.com with SMTP id f84so19467915pfj.0 for ; Tue, 03 Oct 2017 06:09:01 -0700 (PDT) Received: from mx1.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id t21si9770547pfk.89.2017.10.03.06.09.00 for (version=TLS1 cipher=AES128-SHA bits=128/128); Tue, 03 Oct 2017 06:09:00 -0700 (PDT) Date: Tue, 3 Oct 2017 15:08:57 +0200 From: Michal Hocko Subject: Re: [PATCH v9 06/12] mm: zero struct pages during initialization Message-ID: <20171003130857.vohli6lnqj4tdmhl@dhcp22.suse.cz> References: <20170920201714.19817-1-pasha.tatashin@oracle.com> <20170920201714.19817-7-pasha.tatashin@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170920201714.19817-7-pasha.tatashin@oracle.com> Sender: owner-linux-mm@kvack.org List-ID: To: Pavel Tatashin Cc: linux-kernel@vger.kernel.org, sparclinux@vger.kernel.org, linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-arm-kernel@lists.infradead.org, x86@kernel.org, kasan-dev@googlegroups.com, borntraeger@de.ibm.com, heiko.carstens@de.ibm.com, davem@davemloft.net, willy@infradead.org, ard.biesheuvel@linaro.org, mark.rutland@arm.com, will.deacon@arm.com, catalin.marinas@arm.com, sam@ravnborg.org, mgorman@techsingularity.net, steven.sistare@oracle.com, daniel.m.jordan@oracle.com, bob.picco@oracle.com On Wed 20-09-17 16:17:08, Pavel Tatashin wrote: > Add struct page zeroing as a part of initialization of other fields in > __init_single_page(). > > This single thread performance collected on: Intel(R) Xeon(R) CPU E7-8895 > v3 @ 2.60GHz with 1T of memory (268400646 pages in 8 nodes): > > BASE FIX > sparse_init 11.244671836s 0.007199623s > zone_sizes_init 4.879775891s 8.355182299s > -------------------------- > Total 16.124447727s 8.362381922s Hmm, this is confusing. This assumes that sparse_init doesn't zero pages anymore, right? So these number depend on the last patch in the series? > sparse_init is where memory for struct pages is zeroed, and the zeroing > part is moved later in this patch into __init_single_page(), which is > called from zone_sizes_init(). > > Signed-off-by: Pavel Tatashin > Reviewed-by: Steven Sistare > Reviewed-by: Daniel Jordan > Reviewed-by: Bob Picco > Acked-by: Michal Hocko > --- > include/linux/mm.h | 9 +++++++++ > mm/page_alloc.c | 1 + > 2 files changed, 10 insertions(+) > > diff --git a/include/linux/mm.h b/include/linux/mm.h > index f8c10d336e42..50b74d628243 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -94,6 +94,15 @@ extern int mmap_rnd_compat_bits __read_mostly; > #define mm_forbids_zeropage(X) (0) > #endif > > +/* > + * On some architectures it is expensive to call memset() for small sizes. > + * Those architectures should provide their own implementation of "struct page" > + * zeroing by defining this macro in . > + */ > +#ifndef mm_zero_struct_page > +#define mm_zero_struct_page(pp) ((void)memset((pp), 0, sizeof(struct page))) > +#endif > + > /* > * Default maximum number of active map areas, this limits the number of vmas > * per mm struct. Users can overwrite this number by sysctl but there is a > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index a8dbd405ed94..4b630ee91430 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -1170,6 +1170,7 @@ static void free_one_page(struct zone *zone, > static void __meminit __init_single_page(struct page *page, unsigned long pfn, > unsigned long zone, int nid) > { > + mm_zero_struct_page(page); > set_page_links(page, zone, nid, pfn); > init_page_count(page); > page_mapcount_reset(page); > -- > 2.14.1 -- 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