From nobody Wed Apr 1 12:37:23 2026 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C092D3A9623; Tue, 31 Mar 2026 10:49:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774954169; cv=none; b=BfDhfaJ63aIAEhajGoYLzheihPayXBhgjj4CuI6U4gj8QnCyIaiKm1Ovrye+GNLempTJjsqd7kpTsBBSIeCECdo1fSs8rCa7WbtLts2DtEiW6mMz5wZICLDUVCTYl9dS51DhSVtGPtzL6Zkt0qwBxIYdlc1QWc26s/ghjV5ybK4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774954169; c=relaxed/simple; bh=HlILzv4uA6TGQrbzncJ54pWYKVdU9vpGRgmHL6Lwq3E=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=bxHxogSlJj8nRMxzal+Zz2zAg0CMRgbHPGBRS4okzSwVYWsBc5fQZB8kHYD64hQsbnX2uVmzxHB35qf7R2ZkFevgzPAQQLJ+/Z5x8mHR0JALRftq9KWHWup+FjY40rMhhdRTH+eCe2BiExtP4oPrca/HqZiXGNFUXlXTdzHhh1o= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=SLSioINn; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=XtvVs0Ix; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="SLSioINn"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="XtvVs0Ix" From: Nam Cao DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1774954165; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=uYdKAK10x6QwQM9ujCi3jvA8r0QQ2cCaehpH6IP6LQE=; b=SLSioINnq0PolG8gUFzu8ckG1pFybBjl/10glmJ5/VHML3g63JPtNz/824VakyGh5oGy3o IPcf+UwL7Sg8RNt7ZqDyqVIF8iJCO5omaCu0DJHhdVFCNBR9MWRl9zRMf9I6DB0Az3O1Q+ C1rDpoOeLrxFCH4sg9uz8VU/MkXcrVWwluWXb4BxO+oifOLIBaJaHeswu7XISB6H87locw XLQJAYPfY6Du6qi5D+dOVOJ6TaXpDqEDMjo57zfpCnHiGVa8TL/gUCvPsAb6+qEiLoOcb1 Tm0CjFvrgm0hBh4QMyDKTAUvrP4DEmtMp7Wr+bZmqUw5lcBfFoh9G3yBORjrcg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1774954165; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=uYdKAK10x6QwQM9ujCi3jvA8r0QQ2cCaehpH6IP6LQE=; b=XtvVs0IxFK5toHkW6A53h8Mom4QFan/YmcYITDPboyL9cU+nHFg/Qh9ndyFhlF4xcuxDDu OpmwbUyhmHvPkgAA== To: Gabriele Monaco Cc: Steven Rostedt , linux-trace-kernel@vger.kernel.org, linux-kernel@vger.kernel.org, Nam Cao Subject: [PATCH] rv: Allow epoll in rtapp-sleep monitor Date: Tue, 31 Mar 2026 12:49:18 +0200 Message-ID: <20260331104918.2710853-1-namcao@linutronix.de> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Since commit 0c43094f8cc9 ("eventpoll: Replace rwlock with spinlock"), epoll_wait is real-time-safe syscall for sleeping. Add epoll_wait to the list of rt-safe sleeping APIs. Signed-off-by: Nam Cao Reviewed-by: Gabriele Monaco --- kernel/trace/rv/monitors/sleep/sleep.c | 8 ++ kernel/trace/rv/monitors/sleep/sleep.h | 98 ++++++++++++----------- tools/verification/models/rtapp/sleep.ltl | 1 + 3 files changed, 61 insertions(+), 46 deletions(-) diff --git a/kernel/trace/rv/monitors/sleep/sleep.c b/kernel/trace/rv/monit= ors/sleep/sleep.c index c1347da69e9d..59091863c17c 100644 --- a/kernel/trace/rv/monitors/sleep/sleep.c +++ b/kernel/trace/rv/monitors/sleep/sleep.c @@ -49,6 +49,7 @@ static void ltl_atoms_init(struct task_struct *task, stru= ct ltl_monitor *mon, bo ltl_atom_set(mon, LTL_NANOSLEEP_TIMER_ABSTIME, false); ltl_atom_set(mon, LTL_CLOCK_NANOSLEEP, false); ltl_atom_set(mon, LTL_FUTEX_WAIT, false); + ltl_atom_set(mon, LTL_EPOLL_WAIT, false); ltl_atom_set(mon, LTL_FUTEX_LOCK_PI, false); ltl_atom_set(mon, LTL_BLOCK_ON_RT_MUTEX, false); } @@ -63,6 +64,7 @@ static void ltl_atoms_init(struct task_struct *task, stru= ct ltl_monitor *mon, bo ltl_atom_set(mon, LTL_NANOSLEEP_CLOCK_TAI, false); ltl_atom_set(mon, LTL_NANOSLEEP_TIMER_ABSTIME, false); ltl_atom_set(mon, LTL_CLOCK_NANOSLEEP, false); + ltl_atom_set(mon, LTL_EPOLL_WAIT, false); =20 if (strstarts(task->comm, "migration/")) ltl_atom_set(mon, LTL_TASK_IS_MIGRATION, true); @@ -162,6 +164,11 @@ static void handle_sys_enter(void *data, struct pt_reg= s *regs, long id) break; } break; +#ifdef __NR_epoll_wait + case __NR_epoll_wait: + ltl_atom_set(mon, LTL_EPOLL_WAIT, true); + break; +#endif } } =20 @@ -174,6 +181,7 @@ static void handle_sys_exit(void *data, struct pt_regs = *regs, long ret) ltl_atom_set(mon, LTL_NANOSLEEP_CLOCK_MONOTONIC, false); ltl_atom_set(mon, LTL_NANOSLEEP_CLOCK_TAI, false); ltl_atom_set(mon, LTL_NANOSLEEP_TIMER_ABSTIME, false); + ltl_atom_set(mon, LTL_EPOLL_WAIT, false); ltl_atom_update(current, LTL_CLOCK_NANOSLEEP, false); } =20 diff --git a/kernel/trace/rv/monitors/sleep/sleep.h b/kernel/trace/rv/monit= ors/sleep/sleep.h index 2ab46fd218d2..95dc2727c059 100644 --- a/kernel/trace/rv/monitors/sleep/sleep.h +++ b/kernel/trace/rv/monitors/sleep/sleep.h @@ -15,6 +15,7 @@ enum ltl_atom { LTL_ABORT_SLEEP, LTL_BLOCK_ON_RT_MUTEX, LTL_CLOCK_NANOSLEEP, + LTL_EPOLL_WAIT, LTL_FUTEX_LOCK_PI, LTL_FUTEX_WAIT, LTL_KERNEL_THREAD, @@ -40,6 +41,7 @@ static const char *ltl_atom_str(enum ltl_atom atom) "ab_sl", "bl_on_rt_mu", "cl_na", + "ep_wa", "fu_lo_pi", "fu_wa", "ker_th", @@ -75,39 +77,41 @@ static_assert(RV_NUM_BA_STATES <=3D RV_MAX_BA_STATES); =20 static void ltl_start(struct task_struct *task, struct ltl_monitor *mon) { - bool task_is_migration =3D test_bit(LTL_TASK_IS_MIGRATION, mon->atoms); - bool task_is_rcu =3D test_bit(LTL_TASK_IS_RCU, mon->atoms); - bool val40 =3D task_is_rcu || task_is_migration; - bool futex_lock_pi =3D test_bit(LTL_FUTEX_LOCK_PI, mon->atoms); - bool val41 =3D futex_lock_pi || val40; - bool block_on_rt_mutex =3D test_bit(LTL_BLOCK_ON_RT_MUTEX, mon->atoms); - bool val5 =3D block_on_rt_mutex || val41; - bool kthread_should_stop =3D test_bit(LTL_KTHREAD_SHOULD_STOP, mon->atoms= ); - bool abort_sleep =3D test_bit(LTL_ABORT_SLEEP, mon->atoms); - bool val32 =3D abort_sleep || kthread_should_stop; bool woken_by_nmi =3D test_bit(LTL_WOKEN_BY_NMI, mon->atoms); - bool val33 =3D woken_by_nmi || val32; bool woken_by_hardirq =3D test_bit(LTL_WOKEN_BY_HARDIRQ, mon->atoms); - bool val34 =3D woken_by_hardirq || val33; bool woken_by_equal_or_higher_prio =3D test_bit(LTL_WOKEN_BY_EQUAL_OR_HIG= HER_PRIO, mon->atoms); - bool val14 =3D woken_by_equal_or_higher_prio || val34; bool wake =3D test_bit(LTL_WAKE, mon->atoms); - bool val13 =3D !wake; - bool kernel_thread =3D test_bit(LTL_KERNEL_THREAD, mon->atoms); + bool task_is_rcu =3D test_bit(LTL_TASK_IS_RCU, mon->atoms); + bool task_is_migration =3D test_bit(LTL_TASK_IS_MIGRATION, mon->atoms); + bool sleep =3D test_bit(LTL_SLEEP, mon->atoms); + bool rt =3D test_bit(LTL_RT, mon->atoms); + bool nanosleep_timer_abstime =3D test_bit(LTL_NANOSLEEP_TIMER_ABSTIME, mo= n->atoms); bool nanosleep_clock_tai =3D test_bit(LTL_NANOSLEEP_CLOCK_TAI, mon->atoms= ); bool nanosleep_clock_monotonic =3D test_bit(LTL_NANOSLEEP_CLOCK_MONOTONIC= , mon->atoms); - bool val24 =3D nanosleep_clock_monotonic || nanosleep_clock_tai; - bool nanosleep_timer_abstime =3D test_bit(LTL_NANOSLEEP_TIMER_ABSTIME, mo= n->atoms); - bool val25 =3D nanosleep_timer_abstime && val24; - bool clock_nanosleep =3D test_bit(LTL_CLOCK_NANOSLEEP, mon->atoms); - bool val18 =3D clock_nanosleep && val25; + bool kthread_should_stop =3D test_bit(LTL_KTHREAD_SHOULD_STOP, mon->atoms= ); + bool kernel_thread =3D test_bit(LTL_KERNEL_THREAD, mon->atoms); bool futex_wait =3D test_bit(LTL_FUTEX_WAIT, mon->atoms); - bool val9 =3D futex_wait || val18; + bool futex_lock_pi =3D test_bit(LTL_FUTEX_LOCK_PI, mon->atoms); + bool epoll_wait =3D test_bit(LTL_EPOLL_WAIT, mon->atoms); + bool clock_nanosleep =3D test_bit(LTL_CLOCK_NANOSLEEP, mon->atoms); + bool block_on_rt_mutex =3D test_bit(LTL_BLOCK_ON_RT_MUTEX, mon->atoms); + bool abort_sleep =3D test_bit(LTL_ABORT_SLEEP, mon->atoms); + bool val42 =3D task_is_rcu || task_is_migration; + bool val43 =3D futex_lock_pi || val42; + bool val5 =3D block_on_rt_mutex || val43; + bool val34 =3D abort_sleep || kthread_should_stop; + bool val35 =3D woken_by_nmi || val34; + bool val36 =3D woken_by_hardirq || val35; + bool val14 =3D woken_by_equal_or_higher_prio || val36; + bool val13 =3D !wake; + bool val26 =3D nanosleep_clock_monotonic || nanosleep_clock_tai; + bool val27 =3D nanosleep_timer_abstime && val26; + bool val18 =3D clock_nanosleep && val27; + bool val20 =3D val18 || epoll_wait; + bool val9 =3D futex_wait || val20; bool val11 =3D val9 || kernel_thread; - bool sleep =3D test_bit(LTL_SLEEP, mon->atoms); bool val2 =3D !sleep; - bool rt =3D test_bit(LTL_RT, mon->atoms); bool val1 =3D !rt; bool val3 =3D val1 || val2; =20 @@ -124,39 +128,41 @@ static void ltl_start(struct task_struct *task, struc= t ltl_monitor *mon) static void ltl_possible_next_states(struct ltl_monitor *mon, unsigned int state, unsi= gned long *next) { - bool task_is_migration =3D test_bit(LTL_TASK_IS_MIGRATION, mon->atoms); - bool task_is_rcu =3D test_bit(LTL_TASK_IS_RCU, mon->atoms); - bool val40 =3D task_is_rcu || task_is_migration; - bool futex_lock_pi =3D test_bit(LTL_FUTEX_LOCK_PI, mon->atoms); - bool val41 =3D futex_lock_pi || val40; - bool block_on_rt_mutex =3D test_bit(LTL_BLOCK_ON_RT_MUTEX, mon->atoms); - bool val5 =3D block_on_rt_mutex || val41; - bool kthread_should_stop =3D test_bit(LTL_KTHREAD_SHOULD_STOP, mon->atoms= ); - bool abort_sleep =3D test_bit(LTL_ABORT_SLEEP, mon->atoms); - bool val32 =3D abort_sleep || kthread_should_stop; bool woken_by_nmi =3D test_bit(LTL_WOKEN_BY_NMI, mon->atoms); - bool val33 =3D woken_by_nmi || val32; bool woken_by_hardirq =3D test_bit(LTL_WOKEN_BY_HARDIRQ, mon->atoms); - bool val34 =3D woken_by_hardirq || val33; bool woken_by_equal_or_higher_prio =3D test_bit(LTL_WOKEN_BY_EQUAL_OR_HIG= HER_PRIO, mon->atoms); - bool val14 =3D woken_by_equal_or_higher_prio || val34; bool wake =3D test_bit(LTL_WAKE, mon->atoms); - bool val13 =3D !wake; - bool kernel_thread =3D test_bit(LTL_KERNEL_THREAD, mon->atoms); + bool task_is_rcu =3D test_bit(LTL_TASK_IS_RCU, mon->atoms); + bool task_is_migration =3D test_bit(LTL_TASK_IS_MIGRATION, mon->atoms); + bool sleep =3D test_bit(LTL_SLEEP, mon->atoms); + bool rt =3D test_bit(LTL_RT, mon->atoms); + bool nanosleep_timer_abstime =3D test_bit(LTL_NANOSLEEP_TIMER_ABSTIME, mo= n->atoms); bool nanosleep_clock_tai =3D test_bit(LTL_NANOSLEEP_CLOCK_TAI, mon->atoms= ); bool nanosleep_clock_monotonic =3D test_bit(LTL_NANOSLEEP_CLOCK_MONOTONIC= , mon->atoms); - bool val24 =3D nanosleep_clock_monotonic || nanosleep_clock_tai; - bool nanosleep_timer_abstime =3D test_bit(LTL_NANOSLEEP_TIMER_ABSTIME, mo= n->atoms); - bool val25 =3D nanosleep_timer_abstime && val24; - bool clock_nanosleep =3D test_bit(LTL_CLOCK_NANOSLEEP, mon->atoms); - bool val18 =3D clock_nanosleep && val25; + bool kthread_should_stop =3D test_bit(LTL_KTHREAD_SHOULD_STOP, mon->atoms= ); + bool kernel_thread =3D test_bit(LTL_KERNEL_THREAD, mon->atoms); bool futex_wait =3D test_bit(LTL_FUTEX_WAIT, mon->atoms); - bool val9 =3D futex_wait || val18; + bool futex_lock_pi =3D test_bit(LTL_FUTEX_LOCK_PI, mon->atoms); + bool epoll_wait =3D test_bit(LTL_EPOLL_WAIT, mon->atoms); + bool clock_nanosleep =3D test_bit(LTL_CLOCK_NANOSLEEP, mon->atoms); + bool block_on_rt_mutex =3D test_bit(LTL_BLOCK_ON_RT_MUTEX, mon->atoms); + bool abort_sleep =3D test_bit(LTL_ABORT_SLEEP, mon->atoms); + bool val42 =3D task_is_rcu || task_is_migration; + bool val43 =3D futex_lock_pi || val42; + bool val5 =3D block_on_rt_mutex || val43; + bool val34 =3D abort_sleep || kthread_should_stop; + bool val35 =3D woken_by_nmi || val34; + bool val36 =3D woken_by_hardirq || val35; + bool val14 =3D woken_by_equal_or_higher_prio || val36; + bool val13 =3D !wake; + bool val26 =3D nanosleep_clock_monotonic || nanosleep_clock_tai; + bool val27 =3D nanosleep_timer_abstime && val26; + bool val18 =3D clock_nanosleep && val27; + bool val20 =3D val18 || epoll_wait; + bool val9 =3D futex_wait || val20; bool val11 =3D val9 || kernel_thread; - bool sleep =3D test_bit(LTL_SLEEP, mon->atoms); bool val2 =3D !sleep; - bool rt =3D test_bit(LTL_RT, mon->atoms); bool val1 =3D !rt; bool val3 =3D val1 || val2; =20 diff --git a/tools/verification/models/rtapp/sleep.ltl b/tools/verification= /models/rtapp/sleep.ltl index 6379bbeb6212..6f26c4810f78 100644 --- a/tools/verification/models/rtapp/sleep.ltl +++ b/tools/verification/models/rtapp/sleep.ltl @@ -5,6 +5,7 @@ RT_FRIENDLY_SLEEP =3D (RT_VALID_SLEEP_REASON or KERNEL_THRE= AD) =20 RT_VALID_SLEEP_REASON =3D FUTEX_WAIT or RT_FRIENDLY_NANOSLEEP + or EPOLL_WAIT =20 RT_FRIENDLY_NANOSLEEP =3D CLOCK_NANOSLEEP and NANOSLEEP_TIMER_ABSTIME --=20 2.47.3