From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.ozlabs.org (gandalf.ozlabs.org [150.107.74.76]) (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 741F24D8AF; Sun, 1 Sep 2024 11:17:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=150.107.74.76 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725189436; cv=none; b=r/n92oNEt+L9+E5b/QvKCdePOZM9yJ/Nl/8pjl4MaZCcVL09CP0EPMVWk2aDYSa01qYIb0OI8kmONDjHd2TMQ+jTbpaYz1/h2CuM4YQT+FXMXL1/bm7bPSCt3L666tBGopuWscQCIim3DJL2zOvEuEwRFsDFSVIx+nUyXWj9pRc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725189436; c=relaxed/simple; bh=12cWuQ7mup9YTSiqwEKWyZdMv05ZO0xRLyuLQm0ks/k=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=l1EPX2z2Q3FuvDNbCb67DzZyN4RTD96X0UKu1l74ABgUz+UXZM7VBTR3ycjWuopHB0uWH+jIwUD+PLceypyFUJDPeIbk2M7J2LtiQpSwowpUgGMJKHpw7tVLBpOrFVIfBU7TNWLU0hIelhhC8K83dem7T+cixaEkkEO67zkTtPY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au; spf=pass smtp.mailfrom=ellerman.id.au; dkim=pass (2048-bit key) header.d=ellerman.id.au header.i=@ellerman.id.au header.b=oPxs4d9/; arc=none smtp.client-ip=150.107.74.76 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ellerman.id.au Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=ellerman.id.au header.i=@ellerman.id.au header.b="oPxs4d9/" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ellerman.id.au; s=201909; t=1725189425; bh=12cWuQ7mup9YTSiqwEKWyZdMv05ZO0xRLyuLQm0ks/k=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=oPxs4d9/PVThgd1vK3IHuP418JsvF/KuFs3uGnIiPI0SXxmT1DMemyoAckEdH3ccV VYXU6v2evRZ8gsVzKQPhPhPQZXIChDv5R2rm2AwwD6kzu9/8N/PEtOeTYcHIdLrt8t IXUukjkUMXx3Ni8RuqjJtU69mcoErckGRG2WkEdduYTDMVurBWlA7ROh3XXmoPgvtP Q8UcO5zp2+RQNklj0buJqHJSvaPt5XpgK5osQoruTVDMaBCXWo5lDMJpQSRzuHY6Ri gtBx6d0oRek5+QR+s3HXcKhq3+7x2+N+dOsu1cmp4MnUnJMY8fuhi2JSxpqLVv4B8w 7S8gWegPke53w== Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mail.ozlabs.org (Postfix) with ESMTPSA id 4WxTqg3yTGz4wyR; Sun, 1 Sep 2024 21:17:03 +1000 (AEST) From: Michael Ellerman To: Christophe Leroy , Andrew Morton , Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , Nicholas Piggin , Naveen N Rao , Nathan Chancellor , Nick Desaulniers , Bill Wendling , Justin Stitt , Shuah Khan , "Jason A . Donenfeld" Cc: Christophe Leroy , linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-kselftest@vger.kernel.org, llvm@lists.linux.dev, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org, Adhemerval Zanella , Xi Ruoyao Subject: Re: [PATCH v3 1/5] mm: Define VM_DROPPABLE for powerpc/32 In-Reply-To: References: Date: Sun, 01 Sep 2024 21:17:02 +1000 Message-ID: <87bk17ei8h.fsf@mail.lhotse> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain Christophe Leroy writes: > Commit 9651fcedf7b9 ("mm: add MAP_DROPPABLE for designating always > lazily freeable mappings") only adds VM_DROPPABLE for 64 bits > architectures. > > In order to also use the getrandom vDSO implementation on powerpc/32, > use VM_ARCH_1 for VM_DROPPABLE on powerpc/32. This is possible because > VM_ARCH_1 is used for VM_SAO on powerpc and VM_SAO is only for > powerpc/64. Also, there can't be any existing users of VM_SAO on 32-bit, because PROT_SAO (which maps to VM_SAO) is only accepted on CPUs that support SAO, and those CPUs are all 64-bit. cheers