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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8909DC43334 for ; Tue, 28 Jun 2022 21:12:11 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 153818E0002; Tue, 28 Jun 2022 17:12:11 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 104818E0001; Tue, 28 Jun 2022 17:12:11 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id F365D8E0002; Tue, 28 Jun 2022 17:12:10 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id E58888E0001 for ; Tue, 28 Jun 2022 17:12:10 -0400 (EDT) Received: from smtpin08.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id B35A32B11 for ; Tue, 28 Jun 2022 21:12:10 +0000 (UTC) X-FDA: 79628892420.08.AC5ABF4 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by imf14.hostedemail.com (Postfix) with ESMTP id 44F2B100005 for ; Tue, 28 Jun 2022 21:12:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1656450729; 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: in-reply-to:in-reply-to:references:references; bh=SoVc5f5EsdbHoM2jWmLnRkNRe0128omj9CB+dSOcFbc=; b=SaQ/HVb+DBCe3RilM5UjmXkgeHnLU+GHRK9zW3EvO41DuPar0vM/Xdn1d0dcx4jn7Oy9lX G4CnOl3tOOMZnHD5sw4TJLxAOZsDTYfgXp8SaiCya8OyQ0etKuV9UgTZaIufmM1VTZG3o7 zMVgg83KpDFxbnosyXMeWcZuhBxhqZA= Received: from mail-io1-f69.google.com (mail-io1-f69.google.com [209.85.166.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-614-E0TXLgxgOwm1ydLGipDKlw-1; Tue, 28 Jun 2022 17:12:08 -0400 X-MC-Unique: E0TXLgxgOwm1ydLGipDKlw-1 Received: by mail-io1-f69.google.com with SMTP id q13-20020a5d9f0d000000b00669c03397f7so7829414iot.10 for ; Tue, 28 Jun 2022 14:12:08 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=SoVc5f5EsdbHoM2jWmLnRkNRe0128omj9CB+dSOcFbc=; b=CuXEuDIUMTofoZaOPhYab+tJyyZIoRWllfbJLXFqjLtnNrdSWuA6TUOe72jLtkwYj2 Aa7CgQE558m9UZ9jcFwbzmipqda43j6huEd72JbtSu2DHM9uQJaRqraPP4lTcNPh03eE 59P96WpwmtTrt0b+DZGngRDsL0AtEpLdHhgyU2xMkKISAQhb6XBo7UO46fOnGhey7mbB TMQp8Pb9/mnQA7KoWCJP5wUS2re7F8QMF7xfuQxIf5yvMAdur5SLEs53l0pcgVZ7Ol2R nz/7KOe5EftR7kLT1G51gi6scdlxC4XVj9ODj6zKEvS/39aFSIrgu9boqbHMR3EwbiF0 ORqQ== X-Gm-Message-State: AJIora9pqzYAHBDTXVOYrSpGBJVwTojgRcKApLLprGAw0kvagGJvEipc u5U4cJtsCR+JSZP8sOI0BAnOVbNPfshyW+GPN7vJE2qp6VO5yvr5+5tSCsYPM1zFsf7zB0soM8I ypS8017bpBjA= X-Received: by 2002:a02:ccd3:0:b0:33c:8da4:b147 with SMTP id k19-20020a02ccd3000000b0033c8da4b147mr42273jaq.21.1656450727474; Tue, 28 Jun 2022 14:12:07 -0700 (PDT) X-Google-Smtp-Source: AGRyM1uKhNFF2rFpAr4n1P93vvOcuSckFAjQU9zzUorNx12u+I3CakVh/y1yngfkXUS+oyQetllCzQ== X-Received: by 2002:a02:ccd3:0:b0:33c:8da4:b147 with SMTP id k19-20020a02ccd3000000b0033c8da4b147mr42261jaq.21.1656450727259; Tue, 28 Jun 2022 14:12:07 -0700 (PDT) Received: from xz-m1.local (cpec09435e3e0ee-cmc09435e3e0ec.cpe.net.cable.rogers.com. [99.241.198.116]) by smtp.gmail.com with ESMTPSA id e4-20020a0566380cc400b00339dbd4c8d7sm6513261jak.45.2022.06.28.14.12.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 28 Jun 2022 14:12:06 -0700 (PDT) Date: Tue, 28 Jun 2022 17:12:05 -0400 From: Peter Xu To: Nadav Amit Cc: Linux MM , Mike Kravetz , Hugh Dickins , Andrew Morton , Axel Rasmussen , David Hildenbrand , Mike Rapoport , Dave Hansen Subject: Re: [PATCH v1 2/5] userfaultfd: introduce access-likely mode for common operations Message-ID: References: <6EF7D3B4-CF17-407B-A50F-B14D595E99A5@vmware.com> <07B65135-CA6D-4839-BAC0-6D63A94F50C2@vmware.com> <9B0B584B-DE1B-48E3-B448-9D6C02DBDD20@vmware.com> <0E95DBE9-8E0C-4869-A5EA-95C2C4840FD3@vmware.com> MIME-Version: 1.0 In-Reply-To: <0E95DBE9-8E0C-4869-A5EA-95C2C4840FD3@vmware.com> X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1656450730; h=from:from:sender: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: in-reply-to:in-reply-to:references:references:dkim-signature; bh=SoVc5f5EsdbHoM2jWmLnRkNRe0128omj9CB+dSOcFbc=; b=AusKIsJoGAeAqqBmOJTr2NS7KxGd1YiQ6ftPbFYnUe88+GQ6/RHutX0ZYhDPf/8Kp5dHZW I8EmdBeZJqIsqtbpNAp26gCsVFZRbfiOmSCa8BIbCl1ZvFdYtd9R2IekhRohjzWhHiMqZU MdgVnlY3RDnfxoQYHEiTwuc2vsL4svs= ARC-Authentication-Results: i=1; imf14.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b="SaQ/HVb+"; dmarc=pass (policy=none) header.from=redhat.com; spf=none (imf14.hostedemail.com: domain of peterx@redhat.com has no SPF policy when checking 170.10.133.124) smtp.mailfrom=peterx@redhat.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1656450730; a=rsa-sha256; cv=none; b=Wq5XuvasUnkbWAtX6IyyXdH7MhwfX61LhJztfRYEe9GJ2ph7zknrtR+6Y6irmZe3ydiaqL 4lVEC857xJEkzOg7eTTZqn5OpR1wj0q9MMuvykb4jgIdkT23wr51/44D6AIh7Vo1Q61ro4 LJYS/M90UJYqy1cVsWgRSRJhCXpxxLI= X-Rspamd-Queue-Id: 44F2B100005 Authentication-Results: imf14.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b="SaQ/HVb+"; dmarc=pass (policy=none) header.from=redhat.com; spf=none (imf14.hostedemail.com: domain of peterx@redhat.com has no SPF policy when checking 170.10.133.124) smtp.mailfrom=peterx@redhat.com X-Rspam-User: X-Rspamd-Server: rspam11 X-Stat-Signature: rdtoufr9cro6upcrpbgjzpaop4kcogiq X-HE-Tag: 1656450730-77907 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 Tue, Jun 28, 2022 at 09:03:02PM +0000, Nadav Amit wrote: > > Both shmem & hugetlb support private mappings for all three modes, afaict. > > Sorry, let me more clear. I meant private (!VM_SHARED) file-backed memory. I normally use "file-backed" to stand for "shmem + hugetlb" in any uffd context. If you meant anything outside shmem/hugetlb for uffd (e.g. on xfs), then we never support them anyway, do we? Hmm.. What am I ultimately missing? -- Peter Xu