From nobody Sat Feb 7 11:31:31 2026 Received: from mail-yw1-f202.google.com (mail-yw1-f202.google.com [209.85.128.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E211056755 for ; Mon, 18 Mar 2024 19:28:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.202 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710790137; cv=none; b=EYh+HTnnv3ERPJ6yIQd8iTBFsTKxbViVYoseLaKfG8sTlMNz10sIBPxO//beQSczUYF1CJ10PveCpKrHaI9sGdzllHcmec4V0Iw3DcA190PhXdSYwzeR9A4ix0IWBzXKQdoRy6jnyGrs6T8dqNrkUo/PzbgG/A5jlS7yuZ+rLIg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710790137; c=relaxed/simple; bh=qWcin4IBgnnJ7YmYWDXIxqcW/lPwClgTmuho/6O2BcM=; h=Date:Mime-Version:Message-ID:Subject:From:To:Cc:Content-Type; b=jBaVmBL9bxu2SBSncbcbXVQzqv3hTBMO32PkDe7q+i8WFgxi2n58Idv0tYT4KPcGowC2MUi+FiEtGq1yNWkIFggQ/WY3Q8qgbNtbRJBkJMIFTNht2A/Gc/2uFBMve7XaPyC+/jnAEqnNg4t0RNJf4R7SggAtky9sndxPR7CGUjM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--jstultz.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=UYROjDMQ; arc=none smtp.client-ip=209.85.128.202 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--jstultz.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="UYROjDMQ" Received: by mail-yw1-f202.google.com with SMTP id 00721157ae682-610b9326be0so18848607b3.2 for ; Mon, 18 Mar 2024 12:28:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1710790135; x=1711394935; darn=vger.kernel.org; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=F16jgXrZscVwhw0pO80D+sTNG2mCObfU77ILYDXQUA8=; b=UYROjDMQAyXndWtbyCeME1l0nw4MFFl9sL4dAbScbwE6MMF5YcqHk5s4hE7Xa906/5 dp7s57Bkzt66nhNQmVjnPoagRintNsbyQGDc6jka6Y9nMt9neAzfG5ABgyqwl/YCnC18 jDVNHIgG+K1IC0SBVZuEXxBAmCGlYhwp1fG+etYqA1EqsM6PnmjM3VTn86VrQK/Exn3O l9DhnEgaJfELnIONf5sYitDGbBGavu/bDMsE5qPcuaYDEzjh8JoXO8m6+nraT//SQog9 /TbfZmpd/Y785u1CS91Vw3e2GWcoh0ZgPEVmV3NKsIVyUysgaT7XsHwHVzNNGO4hLPNw FS0w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1710790135; x=1711394935; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=F16jgXrZscVwhw0pO80D+sTNG2mCObfU77ILYDXQUA8=; b=ZPaMpBzoQOghUcMT/Q2djlD5Dtc3ARyIJGXvp1Ma/3J0B6wiYZr70GQPN5PR98wm0E KPYZqo4bCwt6v4yUrf/ZDYVCjoLjz2P5/8c8Zspsg3ZRVb90JGAOjNg8PiAr2Ynplhj+ KWGP/EfYBnztDDsKf9/74bGqJG1gnlvouUxaMs7bRKpU38IKsf0yAtSvMPkxr101VMQp EM26Gzr33K6A7479QMINMVviJChSsIaLiQo+2oSNMaaEDv7eg+s+iI37mhBrPmmL7q5r l6CcezOyTKsmVRdToCQVldcsyVp4Yi20+MSwlH+Lkng89WgrKfh6H1xxBlA4TX2v6Di9 szHA== X-Gm-Message-State: AOJu0YwtusglbbR6nFZk/7YGd+dhz2HZMHBHxUTOrXeSIMbyq3ToH1Gm xLJlZMYX5kCNCvE2oJVPUHsenfFXiEMsR2mX2jazk+LK25l89LfFi3zVCSgOwGC3F+Rdp5jkRZI DeHCPGcFe/XekICwRzly9JybwOTWTVDrsfOpq06ybn3xsWwe8VLdT9d6fgD3ie4kfjZUJ6vLy9L U8PWA1TGIrOPRQgw3zbLbwrK9TWqMgdonv4b3Pjmdy19MQ X-Google-Smtp-Source: AGHT+IF4M6hQpCzc7sjvJsjq7d/XVFnrLJoM1jKJ4vpiQHvABmIu4Tx7HTLY9lt7Beoc6McHAyxWe4qwagfR X-Received: from jstultz-noogler2.c.googlers.com ([fda3:e722:ac3:cc00:24:72f4:c0a8:600]) (user=jstultz job=sendgmr) by 2002:a05:6902:118f:b0:dcc:8927:7496 with SMTP id m15-20020a056902118f00b00dcc89277496mr742526ybu.5.1710790134765; Mon, 18 Mar 2024 12:28:54 -0700 (PDT) Date: Mon, 18 Mar 2024 12:28:33 -0700 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 X-Mailer: git-send-email 2.44.0.291.gc1ea87d7ee-goog Message-ID: <20240318192846.75299-1-jstultz@google.com> Subject: [RESEND][PATCH v2] sched: Add trace_sched_waking() tracepoint to sched_ttwu_pending() From: John Stultz To: LKML Cc: John Stultz , Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Daniel Bristot de Oliveira , Phil Auld , Valentin Schneider , kernel-team@android.com, Zimuzo Ezeozue Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Zimuzo reported seeing occasional cases in perfetto traces where tasks went from sleeping directly to trace_sched_wakeup() without always seeing a trace_sched_waking(). Looking at the code, trace_sched_wakeup() is only called in ttwu_do_wakeup() The call paths that get you to ttwu_do_wakeup() are: try_to_wake_up() -> ttwu_do_wakeup() try_to_wake_up() -> ttwu_runnable() -> ttwu_do_wakeup() try_to_wake_up() -> ttwu_queue() -> ttwu_do_activate() -> ttwu_do_wakeup() sched_ttwu_pending() -> ttwu_do_activate() -> ttwu_do_wakeup() where trace_sched_waking() is currently called only in try_to_wake_up(). So add a trace_sched_waking() call to sched_ttwu_pending(), so we see the same state machine transitions. With this change, the number of unexpected state transitions in perfetto was greatly reduced. Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Juri Lelli Cc: Vincent Guittot Cc: Dietmar Eggemann Cc: Steven Rostedt Cc: Ben Segall Cc: Mel Gorman Cc: Daniel Bristot de Oliveira Cc: Phil Auld Cc: Valentin Schneider Cc: kernel-team@android.com Reviewed-by: Phil Auld Reported-by: Zimuzo Ezeozue Signed-off-by: John Stultz --- v2: * Minor commit message fix suggested by Phil Auld --- kernel/sched/core.c | 1 + 1 file changed, 1 insertion(+) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 9116bcc90346..233f06360d6a 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -3894,6 +3894,7 @@ void sched_ttwu_pending(void *arg) if (WARN_ON_ONCE(task_cpu(p) !=3D cpu_of(rq))) set_task_cpu(p, cpu_of(rq)); =20 + trace_sched_waking(p); ttwu_do_activate(rq, p, p->sched_remote_wakeup ? WF_MIGRATED : 0, &rf); } =20 --=20 2.44.0.291.gc1ea87d7ee-goog