From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8DB40125A3 for ; Mon, 18 Dec 2023 09:53:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.19.163.174]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4StwBh3JSKzZdb2; Mon, 18 Dec 2023 17:53:48 +0800 (CST) Received: from kwepemm000003.china.huawei.com (unknown [7.193.23.66]) by mail.maildlp.com (Postfix) with ESMTPS id B4BE9140121; Mon, 18 Dec 2023 17:53:54 +0800 (CST) Received: from [10.174.179.79] (10.174.179.79) by kwepemm000003.china.huawei.com (7.193.23.66) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.35; Mon, 18 Dec 2023 17:53:53 +0800 Subject: Re: [PATCH 1/3] mm: HVO: introduce helper function to update and flush pgtable To: Muchun Song CC: , , , , , , , , , References: <20231214073912.1938330-1-sunnanyong@huawei.com> <20231214073912.1938330-2-sunnanyong@huawei.com> <0100b6c8-24db-fbcf-d45e-763cfccfa0c5@linux.dev> From: Nanyong Sun Message-ID: <1bc0d2d8-567e-9fc1-39a5-ed498ad1d2d2@huawei.com> Date: Mon, 18 Dec 2023 17:53:53 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 In-Reply-To: <0100b6c8-24db-fbcf-d45e-763cfccfa0c5@linux.dev> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 8bit X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To kwepemm000003.china.huawei.com (7.193.23.66) On 2023/12/15 11:36, Muchun Song wrote: > > > On 2023/12/14 15:39, Nanyong Sun wrote: >> Add pmd/pte update and tlb flush helper function to update page >> table. This refactoring patch is designed to facilitate each >> architecture to implement its own special logic in preparation >> for the arm64 architecture to follow the necessary break-before-make >> sequence when updating page tables. >> >> Signed-off-by: Nanyong Sun >> --- >>   mm/hugetlb_vmemmap.c | 55 ++++++++++++++++++++++++++++++++++---------- >>   1 file changed, 43 insertions(+), 12 deletions(-) >> >> diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c >> index 87818ee7f01d..49e8b351def3 100644 >> --- a/mm/hugetlb_vmemmap.c >> +++ b/mm/hugetlb_vmemmap.c >> @@ -45,6 +45,37 @@ struct vmemmap_remap_walk { >>       unsigned long        flags; >>   }; >>   +#ifndef vmemmap_update_pmd >> +static inline void vmemmap_update_pmd(unsigned long start, >> +                      pmd_t *pmd, pte_t *pgtable) >> +{ >> +    pmd_populate_kernel(&init_mm, pmd, pgtable); >> +} >> +#endif >> + >> +#ifndef vmemmap_update_pte >> +static inline void vmemmap_update_pte(unsigned long addr, >> +                      pte_t *pte, pte_t entry) >> +{ >> +    set_pte_at(&init_mm, addr, pte, entry); >> +} >> +#endif >> + >> +#ifndef flush_tlb_vmemmap_all >> +static inline void flush_tlb_vmemmap_all(void) >> +{ >> +    flush_tlb_all(); >> +} >> +#endif >> + >> +#ifndef flush_tlb_vmemmap_range >> +static inline void flush_tlb_vmemmap_range(unsigned long start, >> +                       unsigned long end) >> +{ >> +    flush_tlb_kernel_range(start, end); >> +} >> +#endif > > I'd like to rename both tlb-flush helpers to vmemmap_flush_tlb_all/range > since other helpers all are prefixed with "vmemmap". It'll be more > consistent for me. > > Otherwise LGTM. Thanks. > > Reviewed-by: Muchun Song Hi Muchun， Thank you for your review on this patch set, I'll fix them and send out the v2 version later. > >> + >>   static int split_vmemmap_huge_pmd(pmd_t *pmd, unsigned long start, >> bool flush) >>   { >>       pmd_t __pmd; >> @@ -87,9 +118,9 @@ static int split_vmemmap_huge_pmd(pmd_t *pmd, >> unsigned long start, bool flush) >>             /* Make pte visible before pmd. See comment in >> pmd_install(). */ >>           smp_wmb(); >> -        pmd_populate_kernel(&init_mm, pmd, pgtable); >> +        vmemmap_update_pmd(start, pmd, pgtable); >>           if (flush) >> -            flush_tlb_kernel_range(start, start + PMD_SIZE); >> +            flush_tlb_vmemmap_range(start, start + PMD_SIZE); >>       } else { >>           pte_free_kernel(&init_mm, pgtable); >>       } >> @@ -217,7 +248,7 @@ static int vmemmap_remap_range(unsigned long >> start, unsigned long end, >>       } while (pgd++, addr = next, addr != end); >>         if (walk->remap_pte && !(walk->flags & >> VMEMMAP_REMAP_NO_TLB_FLUSH)) >> -        flush_tlb_kernel_range(start, end); >> +        flush_tlb_vmemmap_range(start, end); >>         return 0; >>   } >> @@ -263,15 +294,15 @@ static void vmemmap_remap_pte(pte_t *pte, >> unsigned long addr, >>             /* >>            * Makes sure that preceding stores to the page contents from >> -         * vmemmap_remap_free() become visible before the set_pte_at() >> -         * write. >> +         * vmemmap_remap_free() become visible before the >> +         * vmemmap_update_pte() write. >>            */ >>           smp_wmb(); >>       } >>         entry = mk_pte(walk->reuse_page, pgprot); >>       list_add(&page->lru, walk->vmemmap_pages); >> -    set_pte_at(&init_mm, addr, pte, entry); >> +    vmemmap_update_pte(addr, pte, entry); >>   } >>     /* >> @@ -310,10 +341,10 @@ static void vmemmap_restore_pte(pte_t *pte, >> unsigned long addr, >>         /* >>        * Makes sure that preceding stores to the page contents become >> visible >> -     * before the set_pte_at() write. >> +     * before the vmemmap_update_pte() write. >>        */ >>       smp_wmb(); >> -    set_pte_at(&init_mm, addr, pte, mk_pte(page, pgprot)); >> +    vmemmap_update_pte(addr, pte, mk_pte(page, pgprot)); >>   } >>     /** >> @@ -576,7 +607,7 @@ long hugetlb_vmemmap_restore_folios(const struct >> hstate *h, >>       } >>         if (restored) >> -        flush_tlb_all(); >> +        flush_tlb_vmemmap_all(); >>       if (!ret) >>           ret = restored; >>       return ret; >> @@ -744,7 +775,7 @@ void hugetlb_vmemmap_optimize_folios(struct >> hstate *h, struct list_head *folio_l >>               break; >>       } >>   -    flush_tlb_all(); >> +    flush_tlb_vmemmap_all(); >>         list_for_each_entry(folio, folio_list, lru) { >>           int ret = __hugetlb_vmemmap_optimize_folio(h, folio, >> @@ -760,7 +791,7 @@ void hugetlb_vmemmap_optimize_folios(struct >> hstate *h, struct list_head *folio_l >>            * allowing more vmemmap remaps to occur. >>            */ >>           if (ret == -ENOMEM && !list_empty(&vmemmap_pages)) { >> -            flush_tlb_all(); >> +            flush_tlb_vmemmap_all(); >>               free_vmemmap_page_list(&vmemmap_pages); >>               INIT_LIST_HEAD(&vmemmap_pages); >>               __hugetlb_vmemmap_optimize_folio(h, folio, >> @@ -769,7 +800,7 @@ void hugetlb_vmemmap_optimize_folios(struct >> hstate *h, struct list_head *folio_l >>           } >>       } >>   -    flush_tlb_all(); >> +    flush_tlb_vmemmap_all(); >>       free_vmemmap_page_list(&vmemmap_pages); >>   } > > .