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 91E87C6FD18 for ; Wed, 19 Apr 2023 20:53:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229655AbjDSUxS (ORCPT ); Wed, 19 Apr 2023 16:53:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54366 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229562AbjDSUxS (ORCPT ); Wed, 19 Apr 2023 16:53:18 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BF56510E0 for ; Wed, 19 Apr 2023 13:53:16 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 59A3061645 for ; Wed, 19 Apr 2023 20:53:16 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B2202C433EF; Wed, 19 Apr 2023 20:53:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1681937595; bh=Wy2QbPs+2Rf0Q56UmdonxQrD/HnE8q7c9S20uGvCMcw=; h=Date:To:From:Subject:From; b=pWYT4CDll6DDTV1wmiWlh2WbrIiGx5KHXCP6wXgyaWq9rB+/UZx47HxzqgRY8x7+K X3eFw2kTmsRmO77oduCeIAjGYa+gDB3SuG7/Dc6b0HXTLJxBSPu2TlxiJzxzj7Giv0 ro91VS8w+zFmX1BHb1FdKjSO6gFFemuyKpnRq0vw= Date: Wed, 19 Apr 2023 13:53:15 -0700 To: mm-commits@vger.kernel.org, muchun.song@linux.dev, mike.kravetz@oracle.com, hughd@google.com, akpm@linux-foundation.org From: Andrew Morton Subject: + hugetlb-pte_alloc_huge-to-replace-huge-pte_alloc_map.patch added to mm-unstable branch Message-Id: <20230419205315.B2202C433EF@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The patch titled Subject: hugetlb: pte_alloc_huge() to replace huge pte_alloc_map() has been added to the -mm mm-unstable branch. Its filename is hugetlb-pte_alloc_huge-to-replace-huge-pte_alloc_map.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/hugetlb-pte_alloc_huge-to-replace-huge-pte_alloc_map.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Hugh Dickins Subject: hugetlb: pte_alloc_huge() to replace huge pte_alloc_map() Date: Tue, 18 Apr 2023 22:22:02 -0700 (PDT) Some architectures can have their hugetlb pages down at the lowest PTE level: their huge_pte_alloc() using pte_alloc_map(), but without any following pte_unmap(). Since none of these arches uses CONFIG_HIGHPTE, this is not seen as a problem at present; but would become a problem if forthcoming changes were to add an rcu_read_lock() into pte_offset_map(), with the rcu_read_unlock() expected in pte_unmap(). Similarly in their huge_pte_offset(): pte_offset_kernel() is good enough for that, but it's probably less confusing if we define pte_offset_huge() along with pte_alloc_huge(). Only define them without CONFIG_HIGHPTE: so there would be a build error to signal if ever more work is needed. For ease of development, define these now for 6.4-rc1, ahead of any use: then architectures can integrate patches using them, independent from mm. Link: https://lkml.kernel.org/r/ae9e7d98-8a3a-cfd9-4762-bcddffdf96cf@google.com Signed-off-by: Hugh Dickins Cc: Mike Kravetz Cc: Muchun Song Signed-off-by: Andrew Morton --- include/linux/hugetlb.h | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) --- a/include/linux/hugetlb.h~hugetlb-pte_alloc_huge-to-replace-huge-pte_alloc_map +++ a/include/linux/hugetlb.h @@ -191,6 +191,23 @@ extern struct list_head huge_boot_pages; /* arch callbacks */ +#ifndef CONFIG_HIGHPTE +/* + * pte_offset_huge() and pte_alloc_huge() are helpers for those architectures + * which may go down to the lowest PTE level in their huge_pte_offset() and + * huge_pte_alloc(): to avoid reliance on pte_offset_map() without pte_unmap(). + */ +static inline pte_t *pte_offset_huge(pmd_t *pmd, unsigned long address) +{ + return pte_offset_kernel(pmd, address); +} +static inline pte_t *pte_alloc_huge(struct mm_struct *mm, pmd_t *pmd, + unsigned long address) +{ + return pte_alloc(mm, pmd) ? NULL : pte_offset_huge(pmd, address); +} +#endif + pte_t *huge_pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long addr, unsigned long sz); /* _ Patches currently in -mm which might be from hughd@google.com are hugetlb-pte_alloc_huge-to-replace-huge-pte_alloc_map.patch ia64-fix-an-addr-to-taddr-in-huge_pte_offset.patch