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 X-Spam-Level: X-Spam-Status: No, score=-11.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 27869C61DD8 for ; Thu, 12 Nov 2020 16:22:23 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 6E0A92224B for ; Thu, 12 Nov 2020 16:22:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="NEZQgmYo" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6E0A92224B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id C01AA6B0068; Thu, 12 Nov 2020 11:22:19 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id BB1486B0073; Thu, 12 Nov 2020 11:22:19 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A79A46B0074; Thu, 12 Nov 2020 11:22:19 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0152.hostedemail.com [216.40.44.152]) by kanga.kvack.org (Postfix) with ESMTP id 7BABC6B0068 for ; Thu, 12 Nov 2020 11:22:19 -0500 (EST) Received: from smtpin03.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 15CB13625 for ; Thu, 12 Nov 2020 16:22:19 +0000 (UTC) X-FDA: 77476283598.03.fire14_050d24d27307 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin03.hostedemail.com (Postfix) with ESMTP id D148728A4ED for ; Thu, 12 Nov 2020 16:22:18 +0000 (UTC) X-HE-Tag: fire14_050d24d27307 X-Filterd-Recvd-Size: 6382 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [63.128.21.124]) by imf46.hostedemail.com (Postfix) with ESMTP for ; Thu, 12 Nov 2020 16:22:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1605198137; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ZW4Cjdd1Y3wnZ8yyT80IuYNIT2MC5nPP7PSwDghDV1Q=; b=NEZQgmYo85TTjpcF52kzhlxScWrst6z9esMx+i5EwXxrIS3msnsQjVGcL7tFMMqx4sIH3k tGNLm17SZpOM3NkWWalzbEYCG52owE8pc5rYln6ehsO5Js7yh6W78KCOi8zhCRiBlYUG2D CWOO5exy241iIVLe6zU3iz09mfPXtPw= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-330-hg3tEq1OPgmdqYl9GCjLuQ-1; Thu, 12 Nov 2020 11:22:13 -0500 X-MC-Unique: hg3tEq1OPgmdqYl9GCjLuQ-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id DB783100F7A6; Thu, 12 Nov 2020 16:22:08 +0000 (UTC) Received: from [10.36.115.61] (ovpn-115-61.ams2.redhat.com [10.36.115.61]) by smtp.corp.redhat.com (Postfix) with ESMTP id B6D5B6EF48; Thu, 12 Nov 2020 16:22:01 +0000 (UTC) Subject: Re: [PATCH v8 2/9] mmap: make mlock_future_check() global To: Mike Rapoport Cc: Andrew Morton , Alexander Viro , Andy Lutomirski , Arnd Bergmann , Borislav Petkov , Catalin Marinas , Christopher Lameter , Dan Williams , Dave Hansen , Elena Reshetova , "H. Peter Anvin" , Ingo Molnar , James Bottomley , "Kirill A. Shutemov" , Matthew Wilcox , Mark Rutland , Mike Rapoport , Michael Kerrisk , Palmer Dabbelt , Paul Walmsley , Peter Zijlstra , Rick Edgecombe , Shuah Khan , Thomas Gleixner , Tycho Andersen , Will Deacon , linux-api@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-nvdimm@lists.01.org, linux-riscv@lists.infradead.org, x86@kernel.org References: <20201110151444.20662-1-rppt@kernel.org> <20201110151444.20662-3-rppt@kernel.org> <9e2fafd7-abb0-aa79-fa66-cd8662307446@redhat.com> <20201110180648.GB4758@kernel.org> From: David Hildenbrand Organization: Red Hat GmbH Message-ID: <3194b507-a85f-965a-e0eb-512a79ede6a9@redhat.com> Date: Thu, 12 Nov 2020 17:22:00 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.6.0 MIME-Version: 1.0 In-Reply-To: <20201110180648.GB4758@kernel.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 10.11.20 19:06, Mike Rapoport wrote: > On Tue, Nov 10, 2020 at 06:17:26PM +0100, David Hildenbrand wrote: >> On 10.11.20 16:14, Mike Rapoport wrote: >>> From: Mike Rapoport >>> >>> It will be used by the upcoming secret memory implementation. >>> >>> Signed-off-by: Mike Rapoport >>> --- >>> mm/internal.h | 3 +++ >>> mm/mmap.c | 5 ++--- >>> 2 files changed, 5 insertions(+), 3 deletions(-) >>> >>> diff --git a/mm/internal.h b/mm/internal.h >>> index c43ccdddb0f6..ae146a260b14 100644 >>> --- a/mm/internal.h >>> +++ b/mm/internal.h >>> @@ -348,6 +348,9 @@ static inline void munlock_vma_pages_all(struct vm_area_struct *vma) >>> extern void mlock_vma_page(struct page *page); >>> extern unsigned int munlock_vma_page(struct page *page); >>> +extern int mlock_future_check(struct mm_struct *mm, unsigned long flags, >>> + unsigned long len); >>> + >>> /* >>> * Clear the page's PageMlocked(). This can be useful in a situation where >>> * we want to unconditionally remove a page from the pagecache -- e.g., >>> diff --git a/mm/mmap.c b/mm/mmap.c >>> index 61f72b09d990..c481f088bd50 100644 >>> --- a/mm/mmap.c >>> +++ b/mm/mmap.c >>> @@ -1348,9 +1348,8 @@ static inline unsigned long round_hint_to_min(unsigned long hint) >>> return hint; >>> } >>> -static inline int mlock_future_check(struct mm_struct *mm, >>> - unsigned long flags, >>> - unsigned long len) >>> +int mlock_future_check(struct mm_struct *mm, unsigned long flags, >>> + unsigned long len) >>> { >>> unsigned long locked, lock_limit; >>> >> >> So, an interesting question is if you actually want to charge secretmem >> pages against mlock now, or if you want a dedicated secretmem cgroup >> controller instead? > > Well, with the current implementation there are three limits an > administrator can use to control secretmem limits: mlock, memcg and > kernel parameter. > > The kernel parameter puts a global upper limit for secretmem usage, > memcg accounts all secretmem allocations, including the unused memory in > large pages caching and mlock allows per task limit for secretmem > mappings, well, like mlock does. > > I didn't consider a dedicated cgroup, as it seems we already have enough > existing knobs and a new one would be unnecessary. To me it feels like the mlock() limit is a wrong fit for secretmem. But maybe there are other cases of using the mlock() limit without actually doing mlock() that I am not aware of (most probably :) )? I mean, my concern is not earth shattering, this can be reworked later. As I said, it just feels wrong. -- Thanks, David / dhildenb