From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 57BC91E8332 for ; Wed, 16 Jul 2025 14:07:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752674845; cv=none; b=nKHJrvdt4jPfC7P3Qi17V5deyfUlkq3NxrHftPKFfYeYLzhhU5jFMHg7zJ4O+dXJNcPL6/9LxGtYjg6qWeQIHNfxUiyVW4oJ2fTa2qeCiifpz2w7tO6slaRexGHknWR/JV+U0dlddnNslktsMmJDGS5dZOqWFDogfOt/OSAPixo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752674845; c=relaxed/simple; bh=tB2hd0yWjPoO6MlhQbxYZc4V8AzKcbCfWKCdItp3044=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=bSd7yYTxlb2kEVv6bUaiT7D0bO68twkd8LznOqJVkjdmsXoI4U6B0Adcg7us1c9vHghCSlxHX6dl4q73DpRTvrfDUJFnyrtVRHdpk4H6I8nha9zShCPGhq/5jGahKhsf9V9LlIuNrXZR97l6rqWTTN6j4ZbK6O/vmauGdz1umQ0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=CFitWqS5; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="CFitWqS5" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1752674843; 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:autocrypt:autocrypt; bh=tB2hd0yWjPoO6MlhQbxYZc4V8AzKcbCfWKCdItp3044=; b=CFitWqS5l5frQBMEsHrqg9jnDwvvkkwRRt2NbotO+EXwYUlgqe0CrEvMHzPu702uCv9fUX DiOcT/H11P/sbh4C0gh6F3m9E9F3dr/B3Z78rWW+m9PbTNgoqBwWYCDhzT7QpEHT/nAFNO HOjkW2x9ocgU/3DRxluqLrpWaqCoT1s= Received: from mail-wr1-f71.google.com (mail-wr1-f71.google.com [209.85.221.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-341-RSrhnPlGO0au09Hal-_hpA-1; Wed, 16 Jul 2025 10:07:22 -0400 X-MC-Unique: RSrhnPlGO0au09Hal-_hpA-1 X-Mimecast-MFC-AGG-ID: RSrhnPlGO0au09Hal-_hpA_1752674841 Received: by mail-wr1-f71.google.com with SMTP id ffacd0b85a97d-3a4ff581df3so509143f8f.1 for ; Wed, 16 Jul 2025 07:07:21 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1752674839; x=1753279639; h=mime-version:user-agent:content-transfer-encoding:autocrypt :references:in-reply-to:date:cc:to:from:subject:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=tB2hd0yWjPoO6MlhQbxYZc4V8AzKcbCfWKCdItp3044=; b=pWdWEUATKtF7IKwZ6gg0AflpL4yGZrPXN0zqbOanDyFJPPM/fRK8vPojw9yh7vzFKj 8js79/YBaRRqWRBiOy/3rMRFYD6kKrZA6Q7HaCMEVXno0zjKMjIckv0cbTEwPYQH2et/ zKM6Zmlu+N87icf0ppnktAbj84d9HpNbkyZmkPuW5tbEhsrrGljMmspo+9ydaQkrNh7y +ltDbkCOkX911PTP4bdCTdyJXgXEwMTWpQ7uT44uEwl8BOG9tzguCPzNB49N+ysKmfzr AI2tPHuxMkUlSfnwla/IR4fHe6Zm0sCDB6wfkQLUSJRurzhtUR5u9gMdyM/8vFCW2QrR bvzQ== X-Gm-Message-State: AOJu0Yym6UDGrLs3OSb2G8EAOsACvMvtabBvjtIhYT/3J97JCbwBXxFQ jQAchtWTOKuz4LJ/Ba5dhx6R8JJH/9WmpUuP7dolR6XYjd7aPdnyLQqXUYr1bp9lmW/tw9gA57t a6/xeD+gtO0/ZdO4vCmnNV6DpuOZF46yU79MSuK/BMolWGYCmjgFl7J+6THxwv2ryIA== X-Gm-Gg: ASbGncv34YiA71yvsnQUvcnUK9c8GMqbo38+EtK60jtZCMX53j8M8hc9JK2G5X6Of82 WDnYW1edeMIl5rE/XJKjUBUJ2nVSHojL2fyuqxHityxu+QoqId0liDUO9LPyI5RFWD+tqE0zQQC yBteCsBnDAmMQ2azJMmX8CMqU1InCP61j8jVHC0MrQh9GAppQb0JYibpGF439Z4IfxCIvfnR1Am Qom60+306Nyp61y6ookj78Q0c8YiZHB0CltdLEN/gZZfuDboeprx0pKbepeixxvGQcA5JzBDvo9 pnb51RCQhlrttQI0evzN6Y/69w1PJBpo/aWtUHsHSiyP8TdNmfuHkqJZU25UxBd9EQ== X-Received: by 2002:a05:6000:2b0c:b0:3a3:70ab:b274 with SMTP id ffacd0b85a97d-3b609524369mr4320863f8f.12.1752674839401; Wed, 16 Jul 2025 07:07:19 -0700 (PDT) X-Google-Smtp-Source: AGHT+IHMGLnEBjMAuOVnncL9pST+yEzGrrXmlW5O5822Ksx735cKfIpDH13N4slQf+5+QbAygFGD/Q== X-Received: by 2002:a05:6000:2b0c:b0:3a3:70ab:b274 with SMTP id ffacd0b85a97d-3b609524369mr4320828f8f.12.1752674838921; Wed, 16 Jul 2025 07:07:18 -0700 (PDT) Received: from gmonaco-thinkpadt14gen3.rmtit.csb ([185.107.56.42]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-4562e83e1d6sm21934665e9.35.2025.07.16.07.07.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 16 Jul 2025 07:07:18 -0700 (PDT) Message-ID: Subject: Re: [PATCH v3 12/17] sched: Adapt sched tracepoints for RV task model From: Gabriele Monaco To: Peter Zijlstra Cc: linux-kernel@vger.kernel.org, Ingo Molnar , Steven Rostedt , Masami Hiramatsu , linux-trace-kernel@vger.kernel.org, Nam Cao , Tomas Glozar , Juri Lelli , Clark Williams , John Kacur Date: Wed, 16 Jul 2025 16:07:16 +0200 In-Reply-To: <20250716134513.GB905792@noisy.programming.kicks-ass.net> References: <20250715071434.22508-1-gmonaco@redhat.com> <20250715071434.22508-13-gmonaco@redhat.com> <20250716123832.GW1613200@noisy.programming.kicks-ass.net> <122cfd4ba6b0805e91ff09526d5d159ff3871964.camel@redhat.com> <20250716134513.GB905792@noisy.programming.kicks-ass.net> Autocrypt: addr=gmonaco@redhat.com; prefer-encrypt=mutual; keydata=mDMEZuK5YxYJKwYBBAHaRw8BAQdAmJ3dM9Sz6/Hodu33Qrf8QH2bNeNbOikqYtxWFLVm0 1a0JEdhYnJpZWxlIE1vbmFjbyA8Z21vbmFjb0ByZWRoYXQuY29tPoiZBBMWCgBBFiEEysoR+AuB3R Zwp6j270psSVh4TfIFAmbiuWMCGwMFCQWjmoAFCwkIBwICIgIGFQoJCAsCBBYCAwECHgcCF4AACgk Q70psSVh4TfJzZgD/TXjnqCyqaZH/Y2w+YVbvm93WX2eqBqiVZ6VEjTuGNs8A/iPrKbzdWC7AicnK xyhmqeUWOzFx5P43S1E1dhsrLWgP Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.56.2 (3.56.2-1.fc42) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 On Wed, 2025-07-16 at 15:45 +0200, Peter Zijlstra wrote: >=20 > I'm not sure I understand the importance of IRQ state when describing > task transitions. >=20 > You know both: >=20 > =C2=A0- schedule() invocations for any one task are in-order; > =C2=A0- schedule() invocations for any one CPU are in-order. >=20 It's to describe latencies, which is the original purpose of the scheduler model: if the event supposed to wake up an RT task occurs with interrupts disabled while scheduling, we'd need to wait for that run to complete. Now to be fair, it doesn't really matter whether that call to __schedule switches or not, but always having a switch event simplifies things while modelling. I can rearrange models like sts (added in this series) not to expect that. Thanks, Gabriele