From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-f69.google.com (mail-pg0-f69.google.com [74.125.83.69]) by kanga.kvack.org (Postfix) with ESMTP id 4BA616B0038 for ; Mon, 15 May 2017 04:28:16 -0400 (EDT) Received: by mail-pg0-f69.google.com with SMTP id x64so105873827pgd.6 for ; Mon, 15 May 2017 01:28:16 -0700 (PDT) Received: from EUR01-DB5-obe.outbound.protection.outlook.com (mail-db5eur01on0127.outbound.protection.outlook.com. [104.47.2.127]) by mx.google.com with ESMTPS id z84si10155031pfk.178.2017.05.15.01.28.14 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Mon, 15 May 2017 01:28:15 -0700 (PDT) Subject: Re: [PATCH] mm/kasan: use kasan_zero_pud for p4d table References: <1494829255-23946-1-git-send-email-iamjoonsoo.kim@lge.com> From: Andrey Ryabinin Message-ID: <60aff3a2-35d5-53f4-65eb-f28d577dab55@virtuozzo.com> Date: Mon, 15 May 2017 11:29:57 +0300 MIME-Version: 1.0 In-Reply-To: <1494829255-23946-1-git-send-email-iamjoonsoo.kim@lge.com> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: js1304@gmail.com, Andrew Morton Cc: "Kirill A . Shutemov" , Alexander Potapenko , Dmitry Vyukov , kasan-dev@googlegroups.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-team@lge.com, Joonsoo Kim On 05/15/2017 09:20 AM, js1304@gmail.com wrote: > From: Joonsoo Kim > > There is missing optimization in zero_p4d_populate() that can save > some memory when mapping zero shadow. Implement it like as others. > > Signed-off-by: Joonsoo Kim Acked-by: Andrey Ryabinin > --- > mm/kasan/kasan_init.c | 12 ++++++++++++ > 1 file changed, 12 insertions(+) > > diff --git a/mm/kasan/kasan_init.c b/mm/kasan/kasan_init.c > index b96a5f7..554e4c0 100644 > --- a/mm/kasan/kasan_init.c > +++ b/mm/kasan/kasan_init.c > @@ -118,6 +118,18 @@ static void __init zero_p4d_populate(pgd_t *pgd, unsigned long addr, > > do { > next = p4d_addr_end(addr, end); > + if (IS_ALIGNED(addr, P4D_SIZE) && end - addr >= P4D_SIZE) { > + pud_t *pud; > + pmd_t *pmd; > + > + p4d_populate(&init_mm, p4d, lm_alias(kasan_zero_pud)); > + pud = pud_offset(p4d, addr); > + pud_populate(&init_mm, pud, lm_alias(kasan_zero_pmd)); > + pmd = pmd_offset(pud, addr); > + pmd_populate_kernel(&init_mm, pmd, > + lm_alias(kasan_zero_pte)); > + continue; > + } > > if (p4d_none(*p4d)) { > p4d_populate(&init_mm, p4d, > -- 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