From nobody Sat Feb 7 16:05:51 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 22F2E1662E4; Fri, 22 Nov 2024 20:28:52 +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=1732307335; cv=none; b=fDJRRwxEKsHzl6RUfH7PisWUwdoycQsuPBXDMgvs6YyK9VZskMoGO/fxgqgyiJ/bZxeqfGGQs5Lw1h3jB+V+S6HbE78onOlVKyHEytwO0lwJAqiAIzWCnSYq3i5UMGiZVWBf3bf65MRefztPBzw5M4A+HzheTGYA6b0AwDSDDFw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732307335; c=relaxed/simple; bh=jnaEE87Td7HGIQHHt6A6qhH1ePOVKMdXcf7v43nHwFA=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=TFEdBt6Puw1YYALB44vEjNMgxxCAHJYl+ilbO89oZR3ZhbgXd2tFSOyTkQCzPgVe+Lb2KKUlQnYjlLH5nsB4JQGZWe1AprpSEgO3o79OqpYV7O5DzbiIWd+iMuckfjkWwGw0hIhWTXlsSL8KapRDLWB6GZmtel0mX+piGXTO+qo= 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=TvRlzpH8; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=+khonDTs; 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="TvRlzpH8"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="+khonDTs" Date: Fri, 22 Nov 2024 21:28:49 +0100 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1732307330; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=JIGUZvxoo1e9xOUa/J29MW200Oz8FYsU0+aB3VY6yGs=; b=TvRlzpH8u5qKyXhapSVBMR5X83VWPYF/D44JgHsXhr/N+1XEPXyCnB3lkRFqEHVgKpiKZU bFaIQcRhL4N5AkxQeeLOFzVNK1jBgLUpzXRHct14F17RusNLm5da0XlUuOVTx2/z2jyani oVlZVQkxAnjYjhvGEDAvfBkQwEV3A6FY4M61XhpTzABGUdO5xeglU3+66keRyYq5g0htCo rfjOSExTAkmUj+nRuG/E9I78bHPQ4zttzFJKmWxWoBn/kA8TIcbn5nIvqin/rDaXub/MWF 6C1YnHCgep+2y8pydSGAY44bs9E5PI+kLMXTov3azf8JW79HzBMoVOhln1RV6w== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1732307330; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=JIGUZvxoo1e9xOUa/J29MW200Oz8FYsU0+aB3VY6yGs=; b=+khonDTsMWynj4M5LrfgUtvlWT4hw6PLCNXq/Ez5F5qQEOok+G991FAt0bTQIu0UPq8UlU yDfwuQC7Gwf0+iDw== From: Sebastian Andrzej Siewior To: Steven Rostedt Cc: linux-trace-kernel@vger.kernel.org, linux-kernel@vger.kernel.org, Peter Zijlstra , tglx@linutronix.de, mingo@kernel.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, bsegall@google.com, mgorman@suse.de, vschneid@redhat.com, ankur.a.arora@oracle.com, efault@gmx.de, Masami Hiramatsu , Mathieu Desnoyers Subject: [PATCH v4] tracing: Record task flag NEED_RESCHED_LAZY. Message-ID: <20241122202849.7DfYpJR0@linutronix.de> References: <20241122173201.tsqK0eeD@linutronix.de> <20241122143742.038c77fa@gandalf.local.home> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable In-Reply-To: <20241122143742.038c77fa@gandalf.local.home> Content-Type: text/plain; charset="utf-8" From: Thomas Gleixner The scheduler added NEED_RESCHED_LAZY scheduling. Record this state as part of trace flags and expose it in the need_resched field. Record and expose NEED_RESCHED_LAZY. [bigeasy: Commit description, documentation bits.] Reviewed-by: Ankur Arora Reviewed-by: Steven Rostedt (Google) Signed-off-by: Thomas Gleixner Signed-off-by: Sebastian Andrzej Siewior --- v3=E2=80=A6v4: - s/borg/both Documentation/trace/ftrace.rst | 4 ++++ include/linux/trace_events.h | 1 + kernel/trace/trace.c | 2 ++ kernel/trace/trace_output.c | 14 +++++++++++++- 4 files changed, 20 insertions(+), 1 deletion(-) diff --git a/Documentation/trace/ftrace.rst b/Documentation/trace/ftrace.rst index 74d5bd801b1a8..272464bb7c602 100644 --- a/Documentation/trace/ftrace.rst +++ b/Documentation/trace/ftrace.rst @@ -1033,9 +1033,13 @@ explains which is which. irqs-off: 'd' interrupts are disabled. '.' otherwise. =20 need-resched: + - 'B' all, TIF_NEED_RESCHED, PREEMPT_NEED_RESCHED and TIF_RESCHED_LAZY is= set, - 'N' both TIF_NEED_RESCHED and PREEMPT_NEED_RESCHED is set, - 'n' only TIF_NEED_RESCHED is set, - 'p' only PREEMPT_NEED_RESCHED is set, + - 'L' both PREEMPT_NEED_RESCHED and TIF_RESCHED_LAZY is set, + - 'b' both TIF_NEED_RESCHED and TIF_RESCHED_LAZY is set, + - 'l' only TIF_RESCHED_LAZY is set - '.' otherwise. =20 hardirq/softirq: diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h index 016b29a56c875..2a5df5b62cfc7 100644 --- a/include/linux/trace_events.h +++ b/include/linux/trace_events.h @@ -184,6 +184,7 @@ unsigned int tracing_gen_ctx_irq_test(unsigned int irqs= _status); =20 enum trace_flag_type { TRACE_FLAG_IRQS_OFF =3D 0x01, + TRACE_FLAG_NEED_RESCHED_LAZY =3D 0x02, TRACE_FLAG_NEED_RESCHED =3D 0x04, TRACE_FLAG_HARDIRQ =3D 0x08, TRACE_FLAG_SOFTIRQ =3D 0x10, diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 3ef047ed97055..be62f0ea1814d 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -2552,6 +2552,8 @@ unsigned int tracing_gen_ctx_irq_test(unsigned int ir= qs_status) trace_flags |=3D TRACE_FLAG_NEED_RESCHED; if (test_preempt_need_resched()) trace_flags |=3D TRACE_FLAG_PREEMPT_RESCHED; + if (IS_ENABLED(CONFIG_ARCH_HAS_PREEMPT_LAZY) && tif_test_bit(TIF_NEED_RES= CHED_LAZY)) + trace_flags |=3D TRACE_FLAG_NEED_RESCHED_LAZY; return (trace_flags << 16) | (min_t(unsigned int, pc & 0xff, 0xf)) | (min_t(unsigned int, migration_disable_value(), 0xf)) << 4; } diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c index e08aee34ef63d..da748b7cbc4d5 100644 --- a/kernel/trace/trace_output.c +++ b/kernel/trace/trace_output.c @@ -462,17 +462,29 @@ int trace_print_lat_fmt(struct trace_seq *s, struct t= race_entry *entry) bh_off ? 'b' : '.'; =20 - switch (entry->flags & (TRACE_FLAG_NEED_RESCHED | + switch (entry->flags & (TRACE_FLAG_NEED_RESCHED | TRACE_FLAG_NEED_RESCHED= _LAZY | TRACE_FLAG_PREEMPT_RESCHED)) { + case TRACE_FLAG_NEED_RESCHED | TRACE_FLAG_NEED_RESCHED_LAZY | TRACE_FLAG_= PREEMPT_RESCHED: + need_resched =3D 'B'; + break; case TRACE_FLAG_NEED_RESCHED | TRACE_FLAG_PREEMPT_RESCHED: need_resched =3D 'N'; break; + case TRACE_FLAG_NEED_RESCHED_LAZY | TRACE_FLAG_PREEMPT_RESCHED: + need_resched =3D 'L'; + break; + case TRACE_FLAG_NEED_RESCHED | TRACE_FLAG_NEED_RESCHED_LAZY: + need_resched =3D 'b'; + break; case TRACE_FLAG_NEED_RESCHED: need_resched =3D 'n'; break; case TRACE_FLAG_PREEMPT_RESCHED: need_resched =3D 'p'; break; + case TRACE_FLAG_NEED_RESCHED_LAZY: + need_resched =3D 'l'; + break; default: need_resched =3D '.'; break; --=20 2.45.2