From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ryan Roberts Subject: Re: [PATCH v1 01/10] mm: Expose clear_huge_page() unconditionally Date: Tue, 27 Jun 2023 08:21:22 +0100 Message-ID: <2ff8ccf6-bf36-48b2-7dc2-e6c0d962f8b7@arm.com> References: <20230626171430.3167004-1-ryan.roberts@arm.com> <20230626171430.3167004-2-ryan.roberts@arm.com> Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: List-ID: Content-Type: text/plain; charset="windows-1252" To: Yu Zhao Cc: Andrew Morton , "Matthew Wilcox (Oracle)" , "Kirill A. Shutemov" , Yin Fengwei , David Hildenbrand , Catalin Marinas , Will Deacon , Geert Uytterhoeven , Christian Borntraeger , Sven Schnelle , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-alpha@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-ia64@vger.kernel.org, linux-m68k@lists On 27/06/2023 02:55, Yu Zhao wrote: > On Mon, Jun 26, 2023 at 11:14=E2=80=AFAM Ryan Roberts wrote: >> >> In preparation for extending vma_alloc_zeroed_movable_folio() to >> allocate a arbitrary order folio, expose clear_huge_page() >> unconditionally, so that it can be used to zero the allocated folio in >> the generic implementation of vma_alloc_zeroed_movable_folio(). >> >> Signed-off-by: Ryan Roberts >> --- >> include/linux/mm.h | 3 ++- >> mm/memory.c | 2 +- >> 2 files changed, 3 insertions(+), 2 deletions(-) >> >> diff --git a/include/linux/mm.h b/include/linux/mm.h >> index 7f1741bd870a..7e3bf45e6491 100644 >> --- a/include/linux/mm.h >> +++ b/include/linux/mm.h >> @@ -3684,10 +3684,11 @@ enum mf_action_page_type { >> */ >> extern const struct attribute_group memory_failure_attr_group; >> >> -#if defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined(CONFIG_HUGETLBFS) >> extern void clear_huge_page(struct page *page, >> unsigned long addr_hint, >> unsigned int pages_per_huge_page); >> + >> +#if defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined(CONFIG_HUGETLBFS) >=20 > We might not want to depend on THP eventually. Right now, we still > have to, unless splitting is optional, which seems to contradict > 06/10. (deferred_split_folio() is a nop without THP.) Yes, I agree - for large anon folios to work, we depend on THP. But I don't think that helps us here. In the next patch, I give vma_alloc_zeroed_movable_folio() an extra `order` parameter. So the generic/default version of the function now needs a way to clear a compound page. I guess I could do something like: static inline struct folio *vma_alloc_zeroed_movable_folio(struct vm_area_struct *vma, unsigned long vaddr, gfp_t gfp, int order) { struct folio *folio; folio =3D vma_alloc_folio(GFP_HIGHUSER_MOVABLE | gfp, order, vma, vaddr, false); if (folio) { #ifdef CONFIG_LARGE_FOLIO clear_huge_page(&folio->page, vaddr, 1U << order); #else BUG_ON(order !=3D 0); clear_user_highpage(&folio->page, vaddr); #endif } return folio; } But that's pretty messy and there's no reason why other users might come al= ong that pass order !=3D 0 and will be surprised by the BUG_ON. 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 33590EB64DD for ; Tue, 27 Jun 2023 07:29:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231285AbjF0H3g (ORCPT ); Tue, 27 Jun 2023 03:29:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33360 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229828AbjF0H3W (ORCPT ); Tue, 27 Jun 2023 03:29:22 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 40761F5; Tue, 27 Jun 2023 00:29:06 -0700 (PDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id A0B162F4; Tue, 27 Jun 2023 00:22:11 -0700 (PDT) Received: from [10.57.76.16] (unknown [10.57.76.16]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 26E843F663; Tue, 27 Jun 2023 00:21:24 -0700 (PDT) Message-ID: <2ff8ccf6-bf36-48b2-7dc2-e6c0d962f8b7@arm.com> Date: Tue, 27 Jun 2023 08:21:22 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0) Gecko/20100101 Thunderbird/102.12.0 Subject: Re: [PATCH v1 01/10] mm: Expose clear_huge_page() unconditionally To: Yu Zhao Cc: Andrew Morton , "Matthew Wilcox (Oracle)" , "Kirill A. Shutemov" , Yin Fengwei , David Hildenbrand , Catalin Marinas , Will Deacon , Geert Uytterhoeven , Christian Borntraeger , Sven Schnelle , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-alpha@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-ia64@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-s390@vger.kernel.org References: <20230626171430.3167004-1-ryan.roberts@arm.com> <20230626171430.3167004-2-ryan.roberts@arm.com> From: Ryan Roberts In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-ia64@vger.kernel.org On 27/06/2023 02:55, Yu Zhao wrote: > On Mon, Jun 26, 2023 at 11:14 AM Ryan Roberts wrote: >> >> In preparation for extending vma_alloc_zeroed_movable_folio() to >> allocate a arbitrary order folio, expose clear_huge_page() >> unconditionally, so that it can be used to zero the allocated folio in >> the generic implementation of vma_alloc_zeroed_movable_folio(). >> >> Signed-off-by: Ryan Roberts >> --- >> include/linux/mm.h | 3 ++- >> mm/memory.c | 2 +- >> 2 files changed, 3 insertions(+), 2 deletions(-) >> >> diff --git a/include/linux/mm.h b/include/linux/mm.h >> index 7f1741bd870a..7e3bf45e6491 100644 >> --- a/include/linux/mm.h >> +++ b/include/linux/mm.h >> @@ -3684,10 +3684,11 @@ enum mf_action_page_type { >> */ >> extern const struct attribute_group memory_failure_attr_group; >> >> -#if defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined(CONFIG_HUGETLBFS) >> extern void clear_huge_page(struct page *page, >> unsigned long addr_hint, >> unsigned int pages_per_huge_page); >> + >> +#if defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined(CONFIG_HUGETLBFS) > > We might not want to depend on THP eventually. Right now, we still > have to, unless splitting is optional, which seems to contradict > 06/10. (deferred_split_folio() is a nop without THP.) Yes, I agree - for large anon folios to work, we depend on THP. But I don't think that helps us here. In the next patch, I give vma_alloc_zeroed_movable_folio() an extra `order` parameter. So the generic/default version of the function now needs a way to clear a compound page. I guess I could do something like: static inline struct folio *vma_alloc_zeroed_movable_folio(struct vm_area_struct *vma, unsigned long vaddr, gfp_t gfp, int order) { struct folio *folio; folio = vma_alloc_folio(GFP_HIGHUSER_MOVABLE | gfp, order, vma, vaddr, false); if (folio) { #ifdef CONFIG_LARGE_FOLIO clear_huge_page(&folio->page, vaddr, 1U << order); #else BUG_ON(order != 0); clear_user_highpage(&folio->page, vaddr); #endif } return folio; } But that's pretty messy and there's no reason why other users might come along that pass order != 0 and will be surprised by the BUG_ON. 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 10686EB64DD for ; Tue, 27 Jun 2023 07:22:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:From:References:Cc:To: Subject:MIME-Version:Date:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=xLyFBB5RrHNABSxO4XdCS7UTXeJ52SIVHb0M4RKOTGo=; b=2XDgGwE/JJR7kJ sgu1BxMVYYh5SyZG9K4WEQTOe5uFKDzBPGecoVGHwA22PQ6aez+f4dGHWri918e7jyBwuzF/aDcGp Hf+AVOVKFq7s1Q8v0YIPByde9wtrktPjFnQVYuMLa6LcHVQCiAtM7qIfTdcE83WMFJwIrRDX511h0 mitKCcLdT5W5jtXxcBnsn/CUkoV9kRdHBxZjG+BbEYUnytHONTM9XWikFW9QkDH68DrY3iqVJxlq2 s6qqSUSBr2umBlmBAKWrK4lRL1PBl7Rq4dd9L4opUyuWA9Pz6SrNMAn7DOHTaCJoutOsqzhf+c6f1 ADFCpbcqWCTaJLdVGO4w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qE31A-00CK6Y-0d; Tue, 27 Jun 2023 07:21:40 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qE310-00CJxM-19 for linux-arm-kernel@lists.infradead.org; Tue, 27 Jun 2023 07:21:33 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id A0B162F4; Tue, 27 Jun 2023 00:22:11 -0700 (PDT) Received: from [10.57.76.16] (unknown [10.57.76.16]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 26E843F663; Tue, 27 Jun 2023 00:21:24 -0700 (PDT) Message-ID: <2ff8ccf6-bf36-48b2-7dc2-e6c0d962f8b7@arm.com> Date: Tue, 27 Jun 2023 08:21:22 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0) Gecko/20100101 Thunderbird/102.12.0 Subject: Re: [PATCH v1 01/10] mm: Expose clear_huge_page() unconditionally To: Yu Zhao Cc: Andrew Morton , "Matthew Wilcox (Oracle)" , "Kirill A. Shutemov" , Yin Fengwei , David Hildenbrand , Catalin Marinas , Will Deacon , Geert Uytterhoeven , Christian Borntraeger , Sven Schnelle , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-alpha@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-ia64@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-s390@vger.kernel.org References: <20230626171430.3167004-1-ryan.roberts@arm.com> <20230626171430.3167004-2-ryan.roberts@arm.com> From: Ryan Roberts In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230627_002130_539652_6B297B27 X-CRM114-Status: GOOD ( 18.41 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org T24gMjcvMDYvMjAyMyAwMjo1NSwgWXUgWmhhbyB3cm90ZToKPiBPbiBNb24sIEp1biAyNiwgMjAy MyBhdCAxMToxNOKAr0FNIFJ5YW4gUm9iZXJ0cyA8cnlhbi5yb2JlcnRzQGFybS5jb20+IHdyb3Rl Ogo+Pgo+PiBJbiBwcmVwYXJhdGlvbiBmb3IgZXh0ZW5kaW5nIHZtYV9hbGxvY196ZXJvZWRfbW92 YWJsZV9mb2xpbygpIHRvCj4+IGFsbG9jYXRlIGEgYXJiaXRyYXJ5IG9yZGVyIGZvbGlvLCBleHBv c2UgY2xlYXJfaHVnZV9wYWdlKCkKPj4gdW5jb25kaXRpb25hbGx5LCBzbyB0aGF0IGl0IGNhbiBi ZSB1c2VkIHRvIHplcm8gdGhlIGFsbG9jYXRlZCBmb2xpbyBpbgo+PiB0aGUgZ2VuZXJpYyBpbXBs ZW1lbnRhdGlvbiBvZiB2bWFfYWxsb2NfemVyb2VkX21vdmFibGVfZm9saW8oKS4KPj4KPj4gU2ln bmVkLW9mZi1ieTogUnlhbiBSb2JlcnRzIDxyeWFuLnJvYmVydHNAYXJtLmNvbT4KPj4gLS0tCj4+ ICBpbmNsdWRlL2xpbnV4L21tLmggfCAzICsrLQo+PiAgbW0vbWVtb3J5LmMgICAgICAgIHwgMiAr LQo+PiAgMiBmaWxlcyBjaGFuZ2VkLCAzIGluc2VydGlvbnMoKyksIDIgZGVsZXRpb25zKC0pCj4+ Cj4+IGRpZmYgLS1naXQgYS9pbmNsdWRlL2xpbnV4L21tLmggYi9pbmNsdWRlL2xpbnV4L21tLmgK Pj4gaW5kZXggN2YxNzQxYmQ4NzBhLi43ZTNiZjQ1ZTY0OTEgMTAwNjQ0Cj4+IC0tLSBhL2luY2x1 ZGUvbGludXgvbW0uaAo+PiArKysgYi9pbmNsdWRlL2xpbnV4L21tLmgKPj4gQEAgLTM2ODQsMTAg KzM2ODQsMTEgQEAgZW51bSBtZl9hY3Rpb25fcGFnZV90eXBlIHsKPj4gICAqLwo+PiAgZXh0ZXJu IGNvbnN0IHN0cnVjdCBhdHRyaWJ1dGVfZ3JvdXAgbWVtb3J5X2ZhaWx1cmVfYXR0cl9ncm91cDsK Pj4KPj4gLSNpZiBkZWZpbmVkKENPTkZJR19UUkFOU1BBUkVOVF9IVUdFUEFHRSkgfHwgZGVmaW5l ZChDT05GSUdfSFVHRVRMQkZTKQo+PiAgZXh0ZXJuIHZvaWQgY2xlYXJfaHVnZV9wYWdlKHN0cnVj dCBwYWdlICpwYWdlLAo+PiAgICAgICAgICAgICAgICAgICAgICAgICAgICAgdW5zaWduZWQgbG9u ZyBhZGRyX2hpbnQsCj4+ICAgICAgICAgICAgICAgICAgICAgICAgICAgICB1bnNpZ25lZCBpbnQg cGFnZXNfcGVyX2h1Z2VfcGFnZSk7Cj4+ICsKPj4gKyNpZiBkZWZpbmVkKENPTkZJR19UUkFOU1BB UkVOVF9IVUdFUEFHRSkgfHwgZGVmaW5lZChDT05GSUdfSFVHRVRMQkZTKQo+IAo+IFdlIG1pZ2h0 IG5vdCB3YW50IHRvIGRlcGVuZCBvbiBUSFAgZXZlbnR1YWxseS4gUmlnaHQgbm93LCB3ZSBzdGls bAo+IGhhdmUgdG8sIHVubGVzcyBzcGxpdHRpbmcgaXMgb3B0aW9uYWwsIHdoaWNoIHNlZW1zIHRv IGNvbnRyYWRpY3QKPiAwNi8xMC4gKGRlZmVycmVkX3NwbGl0X2ZvbGlvKCkgIGlzIGEgbm9wIHdp dGhvdXQgVEhQLikKClllcywgSSBhZ3JlZSAtIGZvciBsYXJnZSBhbm9uIGZvbGlvcyB0byB3b3Jr LCB3ZSBkZXBlbmQgb24gVEhQLiBCdXQgSSBkb24ndAp0aGluayB0aGF0IGhlbHBzIHVzIGhlcmUu CgpJbiB0aGUgbmV4dCBwYXRjaCwgSSBnaXZlIHZtYV9hbGxvY196ZXJvZWRfbW92YWJsZV9mb2xp bygpIGFuIGV4dHJhIGBvcmRlcmAKcGFyYW1ldGVyLiBTbyB0aGUgZ2VuZXJpYy9kZWZhdWx0IHZl cnNpb24gb2YgdGhlIGZ1bmN0aW9uIG5vdyBuZWVkcyBhIHdheSB0bwpjbGVhciBhIGNvbXBvdW5k IHBhZ2UuCgpJIGd1ZXNzIEkgY291bGQgZG8gc29tZXRoaW5nIGxpa2U6Cgogc3RhdGljIGlubGlu ZQogc3RydWN0IGZvbGlvICp2bWFfYWxsb2NfemVyb2VkX21vdmFibGVfZm9saW8oc3RydWN0IHZt X2FyZWFfc3RydWN0ICp2bWEsCgkJCQkgICB1bnNpZ25lZCBsb25nIHZhZGRyLCBnZnBfdCBnZnAs IGludCBvcmRlcikKIHsKIAlzdHJ1Y3QgZm9saW8gKmZvbGlvOwoKCWZvbGlvID0gdm1hX2FsbG9j X2ZvbGlvKEdGUF9ISUdIVVNFUl9NT1ZBQkxFIHwgZ2ZwLAoJCQkJCW9yZGVyLCB2bWEsIHZhZGRy LCBmYWxzZSk7CiAJaWYgKGZvbGlvKSB7CiNpZmRlZiBDT05GSUdfTEFSR0VfRk9MSU8KCQljbGVh cl9odWdlX3BhZ2UoJmZvbGlvLT5wYWdlLCB2YWRkciwgMVUgPDwgb3JkZXIpOwojZWxzZQoJCUJV R19PTihvcmRlciAhPSAwKTsKCQljbGVhcl91c2VyX2hpZ2hwYWdlKCZmb2xpby0+cGFnZSwgdmFk ZHIpOwojZW5kaWYKCX0KCiAJcmV0dXJuIGZvbGlvOwogfQoKQnV0IHRoYXQncyBwcmV0dHkgbWVz c3kgYW5kIHRoZXJlJ3Mgbm8gcmVhc29uIHdoeSBvdGhlciB1c2VycyBtaWdodCBjb21lIGFsb25n CnRoYXQgcGFzcyBvcmRlciAhPSAwIGFuZCB3aWxsIGJlIHN1cnByaXNlZCBieSB0aGUgQlVHX09O LgoKX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KbGludXgt YXJtLWtlcm5lbCBtYWlsaW5nIGxpc3QKbGludXgtYXJtLWtlcm5lbEBsaXN0cy5pbmZyYWRlYWQu b3JnCmh0dHA6Ly9saXN0cy5pbmZyYWRlYWQub3JnL21haWxtYW4vbGlzdGluZm8vbGludXgtYXJt LWtlcm5lbAo=