From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FSL_HELO_FAKE,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_MUTT,USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3954DC10F00 for ; Sat, 9 Mar 2019 03:52:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F22DA20868 for ; Sat, 9 Mar 2019 03:52:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="m9ayY6z/" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726615AbfCIDwe (ORCPT ); Fri, 8 Mar 2019 22:52:34 -0500 Received: from mail-it1-f196.google.com ([209.85.166.196]:36683 "EHLO mail-it1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726352AbfCIDwe (ORCPT ); Fri, 8 Mar 2019 22:52:34 -0500 Received: by mail-it1-f196.google.com with SMTP id v83so24435592itf.1 for ; Fri, 08 Mar 2019 19:52:33 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=m377kZJyLVBelvFNmvVkrDdNPU+nsXM2F8Z21iX0YCQ=; b=m9ayY6z/EzLJdpsqf0ARQ566h+fNvCK43sc+5RsrKitBH7l5IJYnyxlVcknqGnusWm 8TImiEA0X5wRp3f/WwfSofXpUBq0c3qgw+Y2wFaZBQo7LBl8E74BezC+JelThr8zR9vI eXsReEoRW6yjw4vwYV/ysGsz0oWGP+YtMAAiWcGOt7mJ0iXbuQSf2Wu3fxyQlrCRfrc7 Gfoe6yYd2LjcztJi7lssLpYsp5FbeuckI6Y8DKDyuD52nfWkYUyh6Y6MPW3tDGMcTlN3 PjT4U5nwWQ9kNQTSwfKeomhDAc+f1VEWOnQICfQTktrA3mtrIZUZdNq7nVaUtDirbyXF xRrw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=m377kZJyLVBelvFNmvVkrDdNPU+nsXM2F8Z21iX0YCQ=; b=mkW6X2AKqq0TW4EOD6C9DjVnFHOT8ZE22ATXwby8YgD24MUY9fGCTuc/2oLS8G3jr2 w5BEGn98XoSU3mUfWUrkGt3/hh24UHDacR9L3niiundX+Blq8oDjpQWZrcT4Imhf3fcE 19uAOwZVmi3W6uu8NxEzyDaejC6C5/rP9AS+lacm9cvz6E17QSpTPgQAjdlT0i1jHXO3 p48MhtTCpaY44orMoikytJIZAwbXU8zKSPecIrE+hU/ZAPQXCSUS9vMSzGFlp/9Fw26Q mm6mad90/b4UWVjSyVfmvWoCCb0PoRlbRIng8rX2v4Tc61RaLUeEV1O8uS1YNvYjujZE pHLg== X-Gm-Message-State: APjAAAVlZyO0Df6KIIzv7UFhRX/+HLy28+E97sQowSiGUp7BjP3IDbA/ lGkVobJ2ONSt6T34XRbZjYiUrg== X-Google-Smtp-Source: APXvYqwCbLxEH0MAwR0zOVXRARtteHVK25Cgv6im4wYGYLl/7gE17TQQw41o7bgV8bkBqOTUfLBQwQ== X-Received: by 2002:a24:38f:: with SMTP id e137mr8855070ite.99.1552103552925; Fri, 08 Mar 2019 19:52:32 -0800 (PST) Received: from google.com ([2620:15c:183:0:a0c3:519e:9276:fc96]) by smtp.gmail.com with ESMTPSA id n4sm3928063ioa.26.2019.03.08.19.52.31 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Fri, 08 Mar 2019 19:52:32 -0800 (PST) Date: Fri, 8 Mar 2019 20:52:27 -0700 From: Yu Zhao To: Mark Rutland Cc: Catalin Marinas , Will Deacon , "Aneesh Kumar K . V" , Andrew Morton , Nick Piggin , Peter Zijlstra , Joel Fernandes , "Kirill A . Shutemov" , Ard Biesheuvel , Chintan Pandya , Jun Yao , Laura Abbott , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH v2 2/3] arm64: mm: don't call page table ctors for init_mm Message-ID: <20190309035227.GA214016@google.com> References: <20190214211642.2200-1-yuzhao@google.com> <20190218231319.178224-1-yuzhao@google.com> <20190218231319.178224-2-yuzhao@google.com> <20190226151307.GB20230@lakrids.cambridge.arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190226151307.GB20230@lakrids.cambridge.arm.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Feb 26, 2019 at 03:13:07PM +0000, Mark Rutland wrote: > Hi, > > On Mon, Feb 18, 2019 at 04:13:18PM -0700, Yu Zhao wrote: > > init_mm doesn't require page table lock to be initialized at > > any level. Add a separate page table allocator for it, and the > > new one skips page table ctors. > > Just to check, in a previous reply you mentioned we need to call the > ctors for our efi_mm, since we use apply_to_page_range() on that. Is > that only because apply_to_pte_range() tries to take the ptl for non > init_mm? Precisely. > ... or did I miss something else? > > > The ctors allocate memory when ALLOC_SPLIT_PTLOCKS is set. Not > > calling them avoids memory leak in case we call pte_free_kernel() > > on init_mm. > > > > Signed-off-by: Yu Zhao > > Assuming that was all, this patch makes sense to me. FWIW: > > Acked-by: Mark Rutland Thanks. > Thanks, > Mark. > > > --- > > arch/arm64/mm/mmu.c | 15 +++++++++++++-- > > 1 file changed, 13 insertions(+), 2 deletions(-) > > > > diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c > > index fa7351877af3..e8bf8a6300e8 100644 > > --- a/arch/arm64/mm/mmu.c > > +++ b/arch/arm64/mm/mmu.c > > @@ -370,6 +370,16 @@ static void __create_pgd_mapping(pgd_t *pgdir, phys_addr_t phys, > > } while (pgdp++, addr = next, addr != end); > > } > > > > +static phys_addr_t pgd_kernel_pgtable_alloc(int shift) > > +{ > > + void *ptr = (void *)__get_free_page(PGALLOC_GFP); > > + BUG_ON(!ptr); > > + > > + /* Ensure the zeroed page is visible to the page table walker */ > > + dsb(ishst); > > + return __pa(ptr); > > +} > > + > > static phys_addr_t pgd_pgtable_alloc(int shift) > > { > > void *ptr = (void *)__get_free_page(PGALLOC_GFP); > > @@ -591,7 +601,7 @@ static int __init map_entry_trampoline(void) > > /* Map only the text into the trampoline page table */ > > memset(tramp_pg_dir, 0, PGD_SIZE); > > __create_pgd_mapping(tramp_pg_dir, pa_start, TRAMP_VALIAS, PAGE_SIZE, > > - prot, pgd_pgtable_alloc, 0); > > + prot, pgd_kernel_pgtable_alloc, 0); > > > > /* Map both the text and data into the kernel page table */ > > __set_fixmap(FIX_ENTRY_TRAMP_TEXT, pa_start, prot); > > @@ -1067,7 +1077,8 @@ int arch_add_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap, > > flags = NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS; > > > > __create_pgd_mapping(swapper_pg_dir, start, __phys_to_virt(start), > > - size, PAGE_KERNEL, pgd_pgtable_alloc, flags); > > + size, PAGE_KERNEL, pgd_kernel_pgtable_alloc, > > + flags); > > > > return __add_pages(nid, start >> PAGE_SHIFT, size >> PAGE_SHIFT, > > altmap, want_memblock); > > -- > > 2.21.0.rc0.258.g878e2cd30e-goog > >