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[2620:137:e000::1:20]) by mx.google.com with ESMTP id c4-20020a637244000000b005304a8af2adsi7171626pgn.392.2023.06.06.07.49.04; Tue, 06 Jun 2023 07:49:18 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@linutronix.de header.s=2020 header.b="SuKcaX/u"; dkim=neutral (no key) header.i=@linutronix.de; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=linutronix.de Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238282AbjFFOk3 (ORCPT + 99 others); Tue, 6 Jun 2023 10:40:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41988 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238279AbjFFOjU (ORCPT ); Tue, 6 Jun 2023 10:39:20 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 576E31FCE for ; Tue, 6 Jun 2023 07:38:17 -0700 (PDT) Message-ID: <20230606142032.544511403@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1686062282; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: references:references; bh=5ed1VkOh2UBEVrURDClugUqs9wtwWx9MqD/9qEBm3z4=; b=SuKcaX/uHCB7zYDh0doxbGCGrsnwgsbNatkptPv4YN63eB3SI+fQBRMq82+9X4EFM3OX+d Q2aLgkzG3HLJ7+D5/bvQlaB3bL11ESuo19w8/hYUiZwt3mSp9TWAVxafl60oWkz7+H91+E srSXZRI5FUVOyQZuK7uC1Dh6dvQv2dVY+hCX4zLHmot+wvuHplX074nrPq1EBsUUzloub4 5EoleiXrscDNFk0Zw5vecrIt8UcSs1Xmb97R/1dbfj7p5XD9tF2Wh+oD0K55ogMLQFKhVX 18GxPs8IylsMWpmnDC16vZ9T6wOB5amVLNUae6Xz3YALjUdzr+pxOezVnRgyFw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1686062282; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: references:references; bh=5ed1VkOh2UBEVrURDClugUqs9wtwWx9MqD/9qEBm3z4=; b=pva/uGMhqiSbwG4R61C+hTFA66LNiX0FDV8a7t7kF753w3k3Uv6gPo7UxGDBcSDwoBDWN0 SFtTkR5NoQ/IgiCQ== From: Thomas Gleixner To: LKML Cc: Frederic Weisbecker , Anna-Maria Behnsen , John Stultz , Peter Zijlstra , Ingo Molnar , Stephen Boyd , Eric Biederman , Oleg Nesterov Subject: [patch 27/45] posix-timers: Add proper state tracking References: <20230606132949.068951363@linutronix.de> MIME-Version: 1.0 Date: Tue, 6 Jun 2023 16:38:01 +0200 (CEST) X-Spam-Status: No, score=-4.4 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_MED,SPF_HELO_NONE, SPF_PASS,T_SCC_BODY_TEXT_LINE,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1767965152600032869?= X-GMAIL-MSGID: =?utf-8?q?1767965152600032869?= Right now the state tracking is done by two struct members: - it_active: A boolean which tracks armed/disarmed state - it_signal_seq: A sequence counter which is used to invalidate settings and prevent rearming Replace it_active with it_status and keep properly track about the states in one place. This allows to reuse it_signal_seq to track reprogramming, disarm and delete operations in order to drop signals which are related to the state previous of those operations. Signed-off-by: Thomas Gleixner --- include/linux/posix-timers.h | 4 ++-- kernel/time/alarmtimer.c | 2 +- kernel/time/posix-cpu-timers.c | 14 +++++++------- kernel/time/posix-timers.c | 22 +++++++++++++--------- kernel/time/posix-timers.h | 6 ++++++ 5 files changed, 29 insertions(+), 19 deletions(-) --- a/include/linux/posix-timers.h +++ b/include/linux/posix-timers.h @@ -210,7 +210,7 @@ static inline void posix_cputimers_init_ * @kclock: Pointer to the k_clock struct handling this timer * @it_clock: The posix timer clock id * @it_id: The posix timer id for identifying the timer - * @it_active: Marker that timer is active + * @it_status: The status of the timer * @it_overrun: The overrun counter for pending signals * @it_overrun_last: The overrun at the time of the last delivered signal * @it_signal_seq: Sequence count to control signal delivery @@ -231,7 +231,7 @@ struct k_itimer { const struct k_clock *kclock; clockid_t it_clock; timer_t it_id; - int it_active; + int it_status; s64 it_overrun; s64 it_overrun_last; unsigned int it_signal_seq; --- a/kernel/time/alarmtimer.c +++ b/kernel/time/alarmtimer.c @@ -574,7 +574,7 @@ static enum alarmtimer_restart alarm_han */ ptr->it_overrun += __alarm_forward_now(alarm, ptr->it_interval, true); ++ptr->it_signal_seq; - ptr->it_active = 1; + ptr->it_status = POSIX_TIMER_ARMED; result = ALARMTIMER_RESTART; } spin_unlock_irqrestore(&ptr->it_lock, flags); --- a/kernel/time/posix-cpu-timers.c +++ b/kernel/time/posix-cpu-timers.c @@ -453,7 +453,6 @@ static void disarm_timer(struct k_itimer struct cpu_timer *ctmr = &timer->it.cpu; struct posix_cputimer_base *base; - timer->it_active = 0; if (!cpu_timer_dequeue(ctmr)) return; @@ -494,11 +493,12 @@ static int posix_cpu_timer_del(struct k_ */ WARN_ON_ONCE(ctmr->head || timerqueue_node_queued(&ctmr->node)); } else { - if (timer->it.cpu.firing) + if (timer->it.cpu.firing) { ret = TIMER_RETRY; - else + } else { disarm_timer(timer, p); - + timer->it_status = POSIX_TIMER_DISARMED; + } unlock_task_sighand(p, &flags); } @@ -560,7 +560,7 @@ static void arm_timer(struct k_itimer *t struct cpu_timer *ctmr = &timer->it.cpu; u64 newexp = cpu_timer_getexpires(ctmr); - timer->it_active = 1; + timer->it_status = POSIX_TIMER_ARMED; if (!cpu_timer_enqueue(&base->tqhead, ctmr)) return; @@ -670,7 +670,7 @@ static int posix_cpu_timer_set(struct k_ ret = TIMER_RETRY; } else { cpu_timer_dequeue(ctmr); - timer->it_active = 0; + timer->it_status = POSIX_TIMER_DISARMED; } /* @@ -804,7 +804,7 @@ static u64 collect_timerqueue(struct tim rcu_assign_pointer(ctmr->handling, current); cpu_timer_dequeue(ctmr); ktmr = container_of(ctmr, struct k_itimer, it.cpu); - ktmr->it_active = 0; + ktmr->it_status = POSIX_TIMER_DISARMED; list_add_tail(&ctmr->elist, firing); } --- a/kernel/time/posix-timers.c +++ b/kernel/time/posix-timers.c @@ -272,7 +272,7 @@ bool posixtimer_deliver_signal(struct ke if (timr->it_interval && timr->it_signal_seq == info->si_sys_private) { timr->kclock->timer_rearm(timr); - timr->it_active = 1; + timr->it_status = POSIX_TIMER_ARMED; timr->it_overrun_last = timr->it_overrun; timr->it_overrun = -1LL; ++timr->it_signal_seq; @@ -292,14 +292,17 @@ bool posixtimer_deliver_signal(struct ke int posix_timer_queue_signal(struct k_itimer *timr) { + enum posix_timer_state state = POSIX_TIMER_DISARMED; int ret, si_private = 0; enum pid_type type; lockdep_assert_held(&timr->it_lock); - timr->it_active = 0; - if (timr->it_interval) + if (timr->it_interval) { + state = POSIX_TIMER_REQUEUE_PENDING; si_private = ++timr->it_signal_seq; + } + timr->it_status = state; type = !(timr->it_sigev_notify & SIGEV_THREAD_ID) ? PIDTYPE_TGID : PIDTYPE_PID; ret = send_sigqueue(timr->sigq, timr->it_pid, type, si_private); @@ -367,7 +370,7 @@ static enum hrtimer_restart posix_timer_ timr->it_overrun += hrtimer_forward(timer, now, timr->it_interval); ret = HRTIMER_RESTART; ++timr->it_signal_seq; - timr->it_active = 1; + timr->it_status = POSIX_TIMER_ARMED; } } @@ -642,10 +645,10 @@ void common_timer_get(struct k_itimer *t bool iv = !!timr->it_interval; ktime_t now, remaining; - if (!iv && !timr->it_active) { + if (!iv && timr->it_status == POSIX_TIMER_DISARMED) { /* * SIGEV_NONE oneshot timers are never queued and therefore - * timr->it_active is always false. The check below + * timr->it_status is always DISARMED. The check below * vs. remaining time will handle this case. * * For all other timers there is nothing to update here, so @@ -890,7 +893,7 @@ int common_timer_set(struct k_itimer *ti if (kc->timer_try_to_cancel(timr) < 0) return TIMER_RETRY; - timr->it_active = 0; + timr->it_status = POSIX_TIMER_DISARMED; posix_timer_set_common(timr, new_setting); /* Keep timer disarmed when it_value is zero */ @@ -903,7 +906,8 @@ int common_timer_set(struct k_itimer *ti sigev_none = timr->it_sigev_notify == SIGEV_NONE; kc->timer_arm(timr, expires, flags & TIMER_ABSTIME, sigev_none); - timr->it_active = !sigev_none; + if (!sigev_none) + timr->it_status = POSIX_TIMER_ARMED; return 0; } @@ -1002,7 +1006,7 @@ int common_timer_del(struct k_itimer *ti timer->it_interval = 0; if (kc->timer_try_to_cancel(timer) < 0) return TIMER_RETRY; - timer->it_active = 0; + timer->it_status = POSIX_TIMER_DISARMED; return 0; } --- a/kernel/time/posix-timers.h +++ b/kernel/time/posix-timers.h @@ -1,6 +1,12 @@ /* SPDX-License-Identifier: GPL-2.0 */ #define TIMER_RETRY 1 +enum posix_timer_state { + POSIX_TIMER_DISARMED, + POSIX_TIMER_ARMED, + POSIX_TIMER_REQUEUE_PENDING, +}; + struct k_clock { int (*clock_getres)(const clockid_t which_clock, struct timespec64 *tp);