From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754335AbdK2Kde (ORCPT ); Wed, 29 Nov 2017 05:33:34 -0500 Received: from mx1.redhat.com ([209.132.183.28]:55530 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753127AbdK2Kdd (ORCPT ); Wed, 29 Nov 2017 05:33:33 -0500 From: Giuseppe Scrivano To: Andrew Morton Cc: linux-kernel@vger.kernel.org, gregkh@linuxfoundation.org, mingo@kernel.org, dave@stgolabs.net Subject: Re: [RFC PATCH] ipc, mqueue: lazy call kern_mount_data in new namespaces References: <20171127125550.15514-1-gscrivan@redhat.com> <20171128135316.6d7bba7fe909ba3d90e318db@linux-foundation.org> Date: Wed, 29 Nov 2017 11:33:28 +0100 In-Reply-To: <20171128135316.6d7bba7fe909ba3d90e318db@linux-foundation.org> (Andrew Morton's message of "Tue, 28 Nov 2017 13:53:16 -0800") Message-ID: <87wp29l6h3.fsf@redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Wed, 29 Nov 2017 10:33:33 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Andrew Morton writes: > OK, but this simply moves the expense so it happens later on. Why is > that better? the optimization is for new IPC namespaces that don't use mq_open. In this case there won't be any kern_mount_data cost at all. Regards, Giuseppe