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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C179AC001E0 for ; Mon, 31 Jul 2023 11:05:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231671AbjGaLFm (ORCPT ); Mon, 31 Jul 2023 07:05:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53240 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231494AbjGaLFi (ORCPT ); Mon, 31 Jul 2023 07:05:38 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C7E3A1AC for ; Mon, 31 Jul 2023 04:05:37 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 476DC6100F for ; Mon, 31 Jul 2023 11:05:37 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8BA7EC433C8; Mon, 31 Jul 2023 11:05:29 +0000 (UTC) Date: Mon, 31 Jul 2023 12:05:25 +0100 From: Catalin Marinas To: Kefeng Wang Cc: Andrew Morton , Will Deacon , Mike Kravetz , Muchun Song , Mina Almasry , kirill@shutemov.name, joel@joelfernandes.org, william.kucharski@oracle.com, kaleshsingh@google.com, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/4] mm: mremap: use flush_pmd_tlb_range() in move_normal_pmd() Message-ID: References: <20230731074829.79309-1-wangkefeng.wang@huawei.com> <20230731074829.79309-3-wangkefeng.wang@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230731074829.79309-3-wangkefeng.wang@huawei.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jul 31, 2023 at 03:48:27PM +0800, Kefeng Wang wrote: > Archs may need to do special things when flushing thp tlb, > so use the more applicable flush_pud_tlb_range() instead of > flush_tlb_range(). > > Fixes: 2c91bd4a4e2e ("mm: speed up mremap by 20x on large regions") > Signed-off-by: Kefeng Wang > --- > mm/mremap.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/mremap.c b/mm/mremap.c > index 11e06e4ab33b..1883205fa22b 100644 > --- a/mm/mremap.c > +++ b/mm/mremap.c > @@ -284,7 +284,7 @@ static bool move_normal_pmd(struct vm_area_struct *vma, unsigned long old_addr, > VM_BUG_ON(!pmd_none(*new_pmd)); > > pmd_populate(mm, new_pmd, pmd_pgtable(pmd)); > - flush_tlb_range(vma, old_addr, old_addr + PMD_SIZE); > + flush_pmd_tlb_range(vma, old_addr, old_addr + PMD_SIZE); I don't think that's correct for arm64. The assumption in the flush_p*d_tlb_range() was that they are called only for block mappings at that p*d level (and we use FEAT_TTL on arm64 indicating that the leaf level is level 2 for pmd, 1 for pud). IIUC move_normal_pmd() is only called for table pmds which would have a leaf level of 3 (the pte). Same for the next patch doing the equivalent for the pud. -- Catalin