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[99.241.198.116]) by smtp.gmail.com with ESMTPSA id c9-20020a6bb309000000b00669ae49f762sm7885476iof.19.2022.06.21.08.31.06 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 21 Jun 2022 08:31:07 -0700 (PDT) Date: Tue, 21 Jun 2022 11:31:06 -0400 From: Peter Xu To: David Hildenbrand Cc: Nadav Amit , linux-mm@kvack.org, Nadav Amit , Mike Kravetz , Hugh Dickins , Andrew Morton , Axel Rasmussen , Mike Rapoport Subject: Re: [RFC PATCH v2 1/5] userfaultfd: introduce uffd_flags Message-ID: References: <20220619233449.181323-1-namit@vmware.com> <20220619233449.181323-2-namit@vmware.com> MIME-Version: 1.0 In-Reply-To: X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1655825478; a=rsa-sha256; cv=none; b=70gkeHPakWeo82d0iDB3VNkkPoZ4WmlKIaGCwYmjV4PCl/Z6gScQCD+QFxTDWJKZDZvnLN nWNTPZvJUR4EttgXwyJGuCsOE/tLpXRR4xgS21+xMob1ekL7RFxyXHTwlyVYdS98ZpvGNp Rhz4I7tD5bjCW+BEhp8hix2gKtHTA64= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1655825478; 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=pWcgPJJWs+bGYyAQviPxp37bRwbryqhgzchDCqSbcJc=; b=O86Bt5a60I1BMvgxTL0OV66u0VhVqHan1tdIfevopTLqLS7viJqE6GD0n3IR5kljGaMsok t+zlf9j7M6EVq0am0bhVrUtSbHqzcxlv0X1nRNtmbII8kdJZ1EoKLGrY1W4wyYk8aH2DVt zGtMSTZR2siV3GSzEvjUdPPe+/chsPk= ARC-Authentication-Results: i=1; imf04.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=h3sFSOMl; dmarc=pass (policy=none) header.from=redhat.com; spf=none (imf04.hostedemail.com: domain of peterx@redhat.com has no SPF policy when checking 170.10.129.124) smtp.mailfrom=peterx@redhat.com Authentication-Results: imf04.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=h3sFSOMl; dmarc=pass (policy=none) header.from=redhat.com; spf=none (imf04.hostedemail.com: domain of peterx@redhat.com has no SPF policy when checking 170.10.129.124) smtp.mailfrom=peterx@redhat.com X-Rspam-User: X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: 982C4400A8 X-Stat-Signature: 4dnuxqdg6uuh6dg7rpsahtuwpwjdk63m X-HE-Tag: 1655825478-660929 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 21, 2022 at 10:41:19AM +0200, David Hildenbrand wrote: > > @@ -1726,10 +1728,15 @@ static int userfaultfd_copy(struct userfaultfd_ctx *ctx, > > goto out; > > if (uffdio_copy.mode & ~(UFFDIO_COPY_MODE_DONTWAKE|UFFDIO_COPY_MODE_WP)) > > goto out; > > + > > + mode_wp = uffdio_copy.mode & UFFDIO_COPY_MODE_WP; > > + > > + uffd_flags = mode_wp ? UFFD_FLAGS_WP : 0; > > why not simply > > uffd_flags = 0; > if (uffdio_copy.mode & UFFDIO_COPY_MODE_WP) > uffd_flags |= UFFD_FLAGS_WP; > > ? Seconded, or even one-line it? uffd_flags = (uffdio_copy.mode & UFFDIO_COPY_MODE_WP) ? UFFD_FLAGS_WP : 0; Thanks, -- Peter Xu