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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS 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 DDF4BC6778A for ; Tue, 24 Jul 2018 03:23:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7ADDE20852 for ; Tue, 24 Jul 2018 03:23:15 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7ADDE20852 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=xmission.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 S2388171AbeGXE1a (ORCPT ); Tue, 24 Jul 2018 00:27:30 -0400 Received: from out01.mta.xmission.com ([166.70.13.231]:58619 "EHLO out01.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388131AbeGXE1a (ORCPT ); Tue, 24 Jul 2018 00:27:30 -0400 Received: from in02.mta.xmission.com ([166.70.13.52]) by out01.mta.xmission.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.87) (envelope-from ) id 1fhnup-0005VA-Pl; Mon, 23 Jul 2018 21:23:11 -0600 Received: from [97.119.167.31] (helo=x220.xmission.com) by in02.mta.xmission.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.87) (envelope-from ) id 1fhnuo-0005W4-OM; Mon, 23 Jul 2018 21:23:11 -0600 From: ebiederm@xmission.com (Eric W. Biederman) To: Linus Torvalds Cc: Oleg Nesterov , Andrew Morton , , Wen Yang , majiang References: <87h8l9p7bg.fsf@xmission.com> <20180709104158.GA23796@redhat.com> <87sh4so5jv.fsf@xmission.com> <20180709145726.GA26149@redhat.com> <877em4nxo0.fsf@xmission.com> <87lgakm4ol.fsf@xmission.com> <20180710134639.GA2453@redhat.com> <877em2jxyr.fsf_-_@xmission.com> Date: Mon, 23 Jul 2018 22:22:58 -0500 In-Reply-To: <877em2jxyr.fsf_-_@xmission.com> (Eric W. Biederman's message of "Tue, 10 Jul 2018 21:41:16 -0500") Message-ID: <87efft5ncd.fsf_-_@xmission.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-XM-SPF: eid=1fhnuo-0005W4-OM;;;mid=<87efft5ncd.fsf_-_@xmission.com>;;;hst=in02.mta.xmission.com;;;ip=97.119.167.31;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX18LK28Ek+rcUtxQ6Ld97N4cAjvUx2CVWOM= X-SA-Exim-Connect-IP: 97.119.167.31 X-SA-Exim-Mail-From: ebiederm@xmission.com Subject: [PATCH 00/20] PIDTYPE_TGID removal of fork restarts X-SA-Exim-Version: 4.2.1 (built Thu, 05 May 2016 13:38:54 -0600) X-SA-Exim-Scanned: Yes (on in02.mta.xmission.com) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This took longer than I thought to address all of the issues and double check I am not missing something. I have split of a few of the patches so now the patch series appears longer. It now covers less ground. I realized while reviewing the group signals that for none of them is siginfo important. Which means by slightly lowering our quality of implementation in delivering those signals to a brand new process (by not queueing siginfo) I can collect them all in a sigset and the code is no more difficult than a sequence counter. Which means it is straight forward to completely eliminate restarts from fork. The implemenatation of PIDTYPE_TGID remains the same. How it gets used has changed to guarantee that looking up a thread group by the pid of one of it's threads and sending it a signal continues to work exactly the same as before. Please take a look and verify that I have caught everything. I think I have but if not please let me know. Thank you in advance, Eric Eric W. Biederman (20): pids: Initialize leader_pid in init_task pids: Move task_pid_type into sched/signal.h pids: Compute task_tgid using signal->leader_pid kvm: Don't open code task_pid in kvm_vcpu_ioctl pids: Move the pgrp and session pid pointers from task_struct to signal_struct pid: Implement PIDTYPE_TGID signal: Use PIDTYPE_TGID to clearly store where file signals will be sent posix-timers: Noralize good_sigevent signal: Pass pid and pid type into send_sigqueue signal: Pass pid type into group_send_sig_info signal: Pass pid type into send_sigio_to_task & send_sigurg_to_task signal: Pass pid type into do_send_sig_info signal: Push pid type down into send_signal signal: Push pid type down into __send_signal signal: Push pid type down into complete_signal. fork: Move and describe why the code examines PIDNS_ADDING fork: Unconditionally exit if a fatal signal is pending signal: Add calculate_sigpending() fork: Have new threads join on-going signal group stops signal: Don't restart fork when signals come in. arch/ia64/kernel/asm-offsets.c | 4 +- arch/ia64/kernel/fsys.S | 12 ++--- arch/s390/kernel/perf_cpum_sf.c | 2 +- drivers/net/tun.c | 2 +- drivers/platform/x86/thinkpad_acpi.c | 1 + drivers/tty/sysrq.c | 2 +- drivers/tty/tty_io.c | 2 +- fs/autofs/autofs_i.h | 1 + fs/exec.c | 1 + fs/fcntl.c | 72 +++++++++++++-------------- fs/fuse/file.c | 1 + fs/locks.c | 2 +- fs/notify/dnotify/dnotify.c | 3 +- fs/notify/fanotify/fanotify.c | 1 + include/linux/init_task.h | 9 ---- include/linux/pid.h | 11 +---- include/linux/sched.h | 31 +++--------- include/linux/sched/signal.h | 49 +++++++++++++++++-- include/linux/signal.h | 6 ++- include/net/scm.h | 1 + init/init_task.c | 12 +++-- kernel/events/core.c | 2 +- kernel/exit.c | 12 ++--- kernel/fork.c | 70 +++++++++++++++++++-------- kernel/pid.c | 42 ++++++++-------- kernel/signal.c | 94 ++++++++++++++++++++++++++---------- kernel/time/itimer.c | 5 +- kernel/time/posix-cpu-timers.c | 2 +- kernel/time/posix-timers.c | 21 ++++---- mm/oom_kill.c | 4 +- virt/kvm/kvm_main.c | 2 +- 31 files changed, 282 insertions(+), 197 deletions(-)