From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-189.mta0.migadu.com (out-189.mta0.migadu.com [91.218.175.189]) (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 2362140D589 for ; Thu, 11 Jun 2026 07:33:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.189 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781163192; cv=none; b=euqFxmvk/vnyj6t5bOI5psxsW7hJsLS38GBmZIhohUl8vPJurm1xTiUtcbSNc86TNLnVHxpP2vd17VpCdCQTSPGI4JQwOdWYHPJs9fNGPktx/Z/2ahqp5ei7vzggfcm8wSHfGcoBbiloJNS3gcVhi9cSCX5e/UskVNKBh8VC7J4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781163192; c=relaxed/simple; bh=b9Tlx25RXuAClYq9rl38boE9K5SpisHZRsSCO0FaWk0=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=rtRBx7nLOTmYA1p/YJdZ5kJUpDtqft14armGoSWVab0qyO/qJvYEtfItn6iSDMyR2FmEQuZTPuw13p+L8mKAHVZtiNKGbTFXjqbiZgepAdr0k7ZaYe6GQpFdphdL3zoW48UBhmbq0T0eB4+FfWevplMo51Tbr1touMzWxskpHeY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=LQ58nyqR; arc=none smtp.client-ip=91.218.175.189 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="LQ58nyqR" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1781163178; 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=R1MiBfAMRsEVqkQTwOGbLdBbmKfoWauEQVGgroevOKY=; b=LQ58nyqRVya6vT3G83/oprWmS3rp9Ub9WmsgmS+ylJzqF2sDwMaTDwj2kkNO6YaJ0VxmEz OX33MhA2NZNWgGXBz3qXyG6XzqeEGr/IQQR2cxniT2JD170g4zsC/5nSrrWeNs1mtfrNWh cgK5GkSD7rcl6Zq9gUhbUpv3HRw91r0= From: Kunwu Chan To: paulmck@kernel.org, frederic@kernel.org, neeraj.upadhyay@kernel.org, joelagnelf@nvidia.com, josh@joshtriplett.org, boqun@kernel.org, urezki@gmail.com, rostedt@goodmis.org, mathieu.desnoyers@efficios.com, jiangshanlai@gmail.com, qiang.zhang@linux.dev, dave@stgolabs.net Cc: rcu@vger.kernel.org, linux-kernel@vger.kernel.org, Kunwu Chan , Wang Lian Subject: [PATCH] rcu: Use task_state_to_char() in stall-warning prints Date: Thu, 11 Jun 2026 15:32:01 +0800 Message-ID: <20260611073201.3889919-1-kunwu.chan@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT From: Kunwu Chan RCU stall warnings currently print task states as raw hexadecimal values (e.g., ->state=0x402), forcing developers to manually decode them from memory. Replace these raw hex values with the compact, single-letter symbols already established by sched_show_task(): ->state=0x402 becomes ->state=I (TASK_IDLE) ->state=0x0 becomes ->state=R (TASK_RUNNING) ->state=0x2 becomes ->state=D (TASK_UNINTERRUPTIBLE) Convert five print sites across tree_stall.h, rcutorture.c, and hazptrtorture.c to use task_state_to_char() instead of the raw ->__state value. Suggested-by: Zqiang Co-developed-by: Wang Lian Signed-off-by: Wang Lian Signed-off-by: Kunwu Chan --- Based on: linux-rcu repo (dev branch) URL: https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git base-commit: 85bf11e84 ("smp: Make CSD lock acquisition atomic for debug mode") --- kernel/rcu/hazptrtorture.c | 4 ++-- kernel/rcu/rcutorture.c | 4 ++-- kernel/rcu/tree_stall.h | 12 ++++++------ 3 files changed, 10 insertions(+), 10 deletions(-) diff --git a/kernel/rcu/hazptrtorture.c b/kernel/rcu/hazptrtorture.c index 0da0a4606..19ea479c9 100644 --- a/kernel/rcu/hazptrtorture.c +++ b/kernel/rcu/hazptrtorture.c @@ -497,10 +497,10 @@ hazptr_torture_stats_print(void) unsigned long __maybe_unused gp_seq = 0; wtp = READ_ONCE(writer_task); - pr_alert("??? Writer stall state %s(%d) g%lu f%#x ->state %#x cpu %d\n", + pr_alert("??? Writer stall state %s(%d) g%lu f%#x ->state %c cpu %d\n", hazptr_torture_writer_state_getname(), hazptr_torture_writer_state, gp_seq, flags, - wtp == NULL ? ~0U : wtp->__state, + wtp == NULL ? '?' : task_state_to_char(wtp), wtp == NULL ? -1 : (int)task_cpu(wtp)); if (!splatted && wtp) { sched_show_task(wtp); diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index fcb421ced..4d4ebeeea 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -3074,10 +3074,10 @@ rcu_torture_stats_print(void) if (cur_ops->get_gp_data) cur_ops->get_gp_data(&flags, &gp_seq); wtp = READ_ONCE(writer_task); - pr_alert("??? Writer stall state %s(%d) g%lu f%#x ->state %#x cpu %d\n", + pr_alert("??? Writer stall state %s(%d) g%lu f%#x ->state %c cpu %d\n", rcu_torture_writer_state_getname(), rcu_torture_writer_state, gp_seq, flags, - wtp == NULL ? ~0U : wtp->__state, + wtp == NULL ? '?' : task_state_to_char(wtp), wtp == NULL ? -1 : (int)task_cpu(wtp)); if (!splatted && wtp) { sched_show_task(wtp); diff --git a/kernel/rcu/tree_stall.h b/kernel/rcu/tree_stall.h index 317ef91b1..7ca434b08 100644 --- a/kernel/rcu/tree_stall.h +++ b/kernel/rcu/tree_stall.h @@ -596,13 +596,13 @@ static void rcu_check_gp_kthread_starvation(void) if (rcu_is_gp_kthread_starving(&j)) { cpu = gpk ? task_cpu(gpk) : -1; - pr_err("%s kthread starved for %ld jiffies! g%ld f%#x %s(%d) ->state=%#x ->cpu=%d\n", + pr_err("%s kthread starved for %ld jiffies! g%ld f%#x %s(%d) ->state=%c ->cpu=%d\n", rcu_state.name, j, (long)rcu_seq_current(&rcu_state.gp_seq), data_race(READ_ONCE(rcu_state.gp_flags)), gp_state_getname(rcu_state.gp_state), data_race(READ_ONCE(rcu_state.gp_state)), - gpk ? data_race(READ_ONCE(gpk->__state)) : ~0, cpu); + gpk ? task_state_to_char(gpk) : '?', cpu); if (gpk) { struct rcu_data *rdp = per_cpu_ptr(&rcu_data, cpu); @@ -639,12 +639,12 @@ static void rcu_check_gp_kthread_expired_fqs_timer(void) time_after(jiffies, jiffies_fqs + RCU_STALL_MIGHT_MIN) && gpk && !READ_ONCE(gpk->on_rq)) { cpu = task_cpu(gpk); - pr_err("%s kthread timer wakeup didn't happen for %ld jiffies! g%ld f%#x %s(%d) ->state=%#x\n", + pr_err("%s kthread timer wakeup didn't happen for %ld jiffies! g%ld f%#x %s(%d) ->state=%c\n", rcu_state.name, (jiffies - jiffies_fqs), (long)rcu_seq_current(&rcu_state.gp_seq), data_race(READ_ONCE(rcu_state.gp_flags)), // Diagnostic read gp_state_getname(RCU_GP_WAIT_FQS), RCU_GP_WAIT_FQS, - data_race(READ_ONCE(gpk->__state))); + task_state_to_char(gpk)); pr_err("\tPossible timer handling issue on cpu=%d timer-softirq=%u\n", cpu, kstat_softirqs_cpu(TIMER_SOFTIRQ, cpu)); } @@ -971,10 +971,10 @@ void show_rcu_gp_kthreads(void) jr = j - data_race(READ_ONCE(rcu_state.gp_req_activity)); js = j - data_race(READ_ONCE(rcu_state.gp_start)); jw = j - data_race(READ_ONCE(rcu_state.gp_wake_time)); - pr_info("%s: wait state: %s(%d) ->state: %#x ->rt_priority %u delta ->gp_start %lu ->gp_activity %lu ->gp_req_activity %lu ->gp_wake_time %lu ->gp_wake_seq %ld ->gp_seq %ld ->gp_seq_needed %ld ->gp_max %lu ->gp_flags %#x\n", + pr_info("%s: wait state: %s(%d) ->state: %c ->rt_priority %u delta ->gp_start %lu ->gp_activity %lu ->gp_req_activity %lu ->gp_wake_time %lu ->gp_wake_seq %ld ->gp_seq %ld ->gp_seq_needed %ld ->gp_max %lu ->gp_flags %#x\n", rcu_state.name, gp_state_getname(rcu_state.gp_state), data_race(READ_ONCE(rcu_state.gp_state)), - t ? data_race(READ_ONCE(t->__state)) : 0x1ffff, t ? t->rt_priority : 0xffU, + t ? task_state_to_char(t) : '?', t ? t->rt_priority : 0xffU, js, ja, jr, jw, (long)data_race(READ_ONCE(rcu_state.gp_wake_seq)), (long)data_race(READ_ONCE(rcu_state.gp_seq)), (long)data_race(READ_ONCE(rcu_get_root()->gp_seq_needed)), -- 2.43.0