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 824A3C433EF for ; Fri, 4 Feb 2022 04:49:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344033AbiBDEtY (ORCPT ); Thu, 3 Feb 2022 23:49:24 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56570 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230404AbiBDEtY (ORCPT ); Thu, 3 Feb 2022 23:49:24 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5ED32C061714 for ; Thu, 3 Feb 2022 20:49:23 -0800 (PST) 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 C3A2C61AC9 for ; Fri, 4 Feb 2022 04:49:22 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8B40AC340F0; Fri, 4 Feb 2022 04:49:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1643950162; bh=yjWNMIG51D1uSvIE77XEC6AgViA+/ifmW+Z1eUPIVfA=; h=Date:To:From:In-Reply-To:Subject:From; b=1DuAkZSr7pfJNuS0s7+4bR3QnWUCqoO692US7ZKJ692SI002cHVbyahk6SeQTkli3 0mruIDZcCDBsSvVnDIi8Ags7qQM/WsJ7OAMOb4oewhghQgDMxv+vdSVU/qn7Q1DlgQ ioQUuBrc5Djx+4MTXU6gDvjiRoMYXgsZM4b9ARwI= Received: by hp1 (sSMTP sendmail emulation); Thu, 03 Feb 2022 20:49:20 -0800 Date: Thu, 03 Feb 2022 20:49:20 -0800 To: ziy@nvidia.com, will@kernel.org, weixugc@google.com, songmuchun@bytedance.com, rppt@kernel.org, rientjes@google.com, pjt@google.com, mingo@redhat.com, jirislaby@kernel.org, hughd@google.com, hpa@zytor.com, gthelen@google.com, dave.hansen@linux.intel.com, anshuman.khandual@arm.com, aneesh.kumar@linux.ibm.com, pasha.tatashin@soleen.com, akpm@linux-foundation.org, linux-mm@kvack.org, mm-commits@vger.kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org From: Andrew Morton In-Reply-To: <20220203204836.88dcebe504f440686cc63a60@linux-foundation.org> Subject: [patch 04/10] mm/khugepaged: unify collapse pmd clear, flush and free Message-Id: <20220204044920.8B40AC340F0@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org From: Pasha Tatashin Subject: mm/khugepaged: unify collapse pmd clear, flush and free Unify the code that flushes, clears pmd entry, and frees the PTE table level into a new function collapse_and_free_pmd(). This cleanup is useful as in the next patch we will add another call to this function to iterate through PTE prior to freeing the level for page table check. Link: https://lkml.kernel.org/r/20220131203249.2832273-4-pasha.tatashin@soleen.com Signed-off-by: Pasha Tatashin Acked-by: David Rientjes Cc: Aneesh Kumar K.V Cc: Anshuman Khandual Cc: Dave Hansen Cc: Greg Thelen Cc: H. Peter Anvin Cc: Hugh Dickins Cc: Ingo Molnar Cc: Jiri Slaby Cc: Mike Rapoport Cc: Muchun Song Cc: Paul Turner Cc: Wei Xu Cc: Will Deacon Cc: Zi Yan Signed-off-by: Andrew Morton --- mm/khugepaged.c | 34 ++++++++++++++++++---------------- 1 file changed, 18 insertions(+), 16 deletions(-) --- a/mm/khugepaged.c~mm-khugepaged-unify-collapse-pmd-clear-flush-and-free +++ a/mm/khugepaged.c @@ -1416,6 +1416,19 @@ static int khugepaged_add_pte_mapped_thp return 0; } +static void collapse_and_free_pmd(struct mm_struct *mm, struct vm_area_struct *vma, + unsigned long addr, pmd_t *pmdp) +{ + spinlock_t *ptl; + pmd_t pmd; + + ptl = pmd_lock(vma->vm_mm, pmdp); + pmd = pmdp_collapse_flush(vma, addr, pmdp); + spin_unlock(ptl); + mm_dec_nr_ptes(mm); + pte_free(mm, pmd_pgtable(pmd)); +} + /** * collapse_pte_mapped_thp - Try to collapse a pte-mapped THP for mm at * address haddr. @@ -1433,7 +1446,7 @@ void collapse_pte_mapped_thp(struct mm_s struct vm_area_struct *vma = find_vma(mm, haddr); struct page *hpage; pte_t *start_pte, *pte; - pmd_t *pmd, _pmd; + pmd_t *pmd; spinlock_t *ptl; int count = 0; int i; @@ -1509,12 +1522,7 @@ void collapse_pte_mapped_thp(struct mm_s } /* step 4: collapse pmd */ - ptl = pmd_lock(vma->vm_mm, pmd); - _pmd = pmdp_collapse_flush(vma, haddr, pmd); - spin_unlock(ptl); - mm_dec_nr_ptes(mm); - pte_free(mm, pmd_pgtable(_pmd)); - + collapse_and_free_pmd(mm, vma, haddr, pmd); drop_hpage: unlock_page(hpage); put_page(hpage); @@ -1552,7 +1560,7 @@ static void retract_page_tables(struct a struct vm_area_struct *vma; struct mm_struct *mm; unsigned long addr; - pmd_t *pmd, _pmd; + pmd_t *pmd; i_mmap_lock_write(mapping); vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff) { @@ -1591,14 +1599,8 @@ static void retract_page_tables(struct a * reverse order. Trylock is a way to avoid deadlock. */ if (mmap_write_trylock(mm)) { - if (!khugepaged_test_exit(mm)) { - spinlock_t *ptl = pmd_lock(mm, pmd); - /* assume page table is clear */ - _pmd = pmdp_collapse_flush(vma, addr, pmd); - spin_unlock(ptl); - mm_dec_nr_ptes(mm); - pte_free(mm, pmd_pgtable(_pmd)); - } + if (!khugepaged_test_exit(mm)) + collapse_and_free_pmd(mm, vma, addr, pmd); mmap_write_unlock(mm); } else { /* Try again later */ _