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Biederman" To: Linus Torvalds Cc: Christian Brauner , Tejun Heo , Petr Mladek , Lai Jiangshan , Michal Hocko , Linux Kernel Mailing List , Peter Zijlstra , Thomas Gleixner , Ingo Molnar , Andrew Morton , Oleg Nesterov References: <20220622140853.31383-1-pmladek@suse.com> <874k0863x8.fsf@email.froward.int.ebiederm.org> <87pmiw1fy6.fsf@email.froward.int.ebiederm.org> Date: Sat, 25 Jun 2022 19:19:27 -0500 In-Reply-To: (Linus Torvalds's message of "Sat, 25 Jun 2022 16:48:38 -0700") Message-ID: <87y1xkwa28.fsf@email.froward.int.ebiederm.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-XM-SPF: eid=1o5Fzy-00AYHt-KI;;;mid=<87y1xkwa28.fsf@email.froward.int.ebiederm.org>;;;hst=in01.mta.xmission.com;;;ip=68.227.174.4;;;frm=ebiederm@xmission.com;;;spf=softfail X-XM-AID: U2FsdGVkX1/D80Oi4qTinv1YmPEUUSX8Os0cPZfAqnk= X-SA-Exim-Connect-IP: 68.227.174.4 X-SA-Exim-Mail-From: ebiederm@xmission.com X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net X-Spam-Status: No, score=-2.6 required=5.0 tests=BAYES_00,RCVD_IN_DNSWL_LOW, RCVD_IN_MSPIKE_H3,RCVD_IN_MSPIKE_WL,SPF_HELO_NONE,SPF_PASS, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-DCC: XMission; sa04 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: **;Linus Torvalds X-Spam-Relay-Country: X-Spam-Timing: total 352 ms - load_scoreonly_sql: 0.12 (0.0%), signal_user_changed: 14 (4.1%), b_tie_ro: 12 (3.4%), parse: 1.68 (0.5%), extract_message_metadata: 19 (5.4%), get_uri_detail_list: 1.13 (0.3%), tests_pri_-1000: 23 (6.5%), tests_pri_-950: 1.93 (0.5%), tests_pri_-900: 1.39 (0.4%), tests_pri_-90: 80 (22.7%), check_bayes: 77 (22.0%), b_tokenize: 7 (2.0%), b_tok_get_all: 6 (1.8%), b_comp_prob: 2.3 (0.7%), b_tok_touch_all: 58 (16.4%), b_finish: 1.26 (0.4%), tests_pri_0: 178 (50.5%), check_dkim_signature: 0.85 (0.2%), check_dkim_adsp: 3.6 (1.0%), poll_dns_idle: 0.99 (0.3%), tests_pri_10: 4.7 (1.3%), tests_pri_500: 23 (6.6%), rewrite_mail: 0.00 (0.0%) Subject: Re: re. Spurious wakeup on a newly created kthread X-SA-Exim-Version: 4.2.1 (built Sat, 08 Feb 2020 21:53:50 +0000) X-SA-Exim-Scanned: Yes (on in01.mta.xmission.com) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Linus Torvalds writes: > Anyway, the whole "don't wake up thread until it's all done" is a > separate and independent issue from the "odd use of kthreadd" issue. Yes. "don't wake up a kthread until it's all done" is a much easier change that will simplify things tremendously. Further it is necessary for Peter Zijlstra's rewrite of the kernel freezer. As anything that isn't a special stop state (which TASK_UNINTERRUPTIBLE is not) will receive a spurious wake up on when thawed out. Eric