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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham 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 24A09ECDFB1 for ; Tue, 17 Jul 2018 11:59:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DA547208E3 for ; Tue, 17 Jul 2018 11:59:57 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DA547208E3 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731248AbeGQMcO (ORCPT ); Tue, 17 Jul 2018 08:32:14 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:42064 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1731154AbeGQMcN (ORCPT ); Tue, 17 Jul 2018 08:32:13 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id C5D1E402332F; Tue, 17 Jul 2018 11:59:54 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.34.27.30]) by smtp.corp.redhat.com (Postfix) with SMTP id 5D8252026D68; Tue, 17 Jul 2018 11:59:53 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Tue, 17 Jul 2018 13:59:54 +0200 (CEST) Date: Tue, 17 Jul 2018 13:59:52 +0200 From: Oleg Nesterov To: "Eric W. Biederman" Cc: Linus Torvalds , Andrew Morton , linux-kernel@vger.kernel.org, Wen Yang , majiang Subject: Re: [RFC][PATCH 05/11] pids: Move the pgrp and session pid pointers from task_struct to signal_struct Message-ID: <20180717115952.GA29647@redhat.com> References: <877em2jxyr.fsf_-_@xmission.com> <20180711024459.10654-5-ebiederm@xmission.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180711024459.10654-5-ebiederm@xmission.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 2.78 on 10.11.54.4 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.6]); Tue, 17 Jul 2018 11:59:54 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.6]); Tue, 17 Jul 2018 11:59:54 +0000 (UTC) for IP:'10.11.54.4' DOMAIN:'int-mx04.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'oleg@redhat.com' RCPT:'' Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This is a bit offtopic/cosmetic and we can do this later, just for record before I forget this... On 07/10, Eric W. Biederman wrote: > > +static struct pid **task_pid_ptr(struct task_struct *task, enum pid_type type) > +{ > + return (type == PIDTYPE_PID) ? > + &task->thread_pid : > + (type == __PIDTYPE_TGID) ? > + &task->signal->leader_pid : > + &task->signal->pids[type]; > +} This new helper is (simplified after you removed __PIDTYPE_TGID/leader_pid) can have more users: task_pid_type(), init_task_pid(). In fact even (say) task_tgid() can use it if we export it inline. And if we make task_pid_ptr() the only user of signal->pids[] array we can shrink it, signal->pids[0] is not used. Or may be we can simply redefine enum pid_type, we can define PIDTYPE_PID == -1 or move it at the end, or do something else. Once again, this is just random/minor thoughts, feel free to ignore. Oleg.