From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from simark.ca by simark.ca with LMTP id YKMaD5jRDGYb8CAAWB0awg (envelope-from ) for ; Tue, 02 Apr 2024 23:48:40 -0400 Authentication-Results: simark.ca; dkim=pass (2048-bit key; unprotected) header.d=lists.lttng.org header.i=@lists.lttng.org header.a=rsa-sha256 header.s=default header.b=a877Eix7; dkim-atps=neutral Received: by simark.ca (Postfix, from userid 112) id 39F341E0C0; Tue, 2 Apr 2024 23:48:40 -0400 (EDT) Received: from lists.lttng.org (lists.lttng.org [167.114.26.123]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by simark.ca (Postfix) with ESMTPS id 2CAF91E08C for ; Tue, 2 Apr 2024 23:48:38 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=lists.lttng.org; s=default; t=1712116117; bh=WcevrMO2Lw4s/LH8fAkHo4+DuY2y3s2ueBQfcvt6XPI=; h=References:In-Reply-To:Date:To:Subject:List-Id:List-Unsubscribe: List-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To:Cc: From; b=a877Eix7tpCKsMooYycVOLVg/NyvSBokf1e6KItf5pb1f6IhAYFRAkAOjGwKJbkx0 xaaGme2xPUkNPbygDxVt7tjAGYUUlMsVzbCxwmUdA5u3WAiojKlNyfndkjBa8nnwat D1bODHRAVBwSlGppzW2c99ETaG54Lu8KdroqC0296P0UWvsjWCqq3nbhHpYtpzgXft MQIz2OfkxeaQSUX+5ZLYDxBmQcmVVztsOiRItr1Xiw9Pq9xc+TPK1oEBWk99mIaorG scOceNH+Kd/EVvUGhgiXQ3GzzibpO8zkvcfVbHdOJ84ALmGpWaKINB7PG9O3mlUL7v TJSMVFqWKw5Gw== Received: from lists-lttng01.efficios.com (localhost [IPv6:::1]) by lists.lttng.org (Postfix) with ESMTP id 4V8W1x4sHsz2Zg6; Tue, 2 Apr 2024 23:48:37 -0400 (EDT) Received: from mail-lj1-x22e.google.com (mail-lj1-x22e.google.com [IPv6:2a00:1450:4864:20::22e]) by lists.lttng.org (Postfix) with ESMTPS id 4V8W1v5bYkz2Zg5 for ; Tue, 2 Apr 2024 23:48:35 -0400 (EDT) Received: by mail-lj1-x22e.google.com with SMTP id 38308e7fff4ca-2d48f03a8bbso4602821fa.0 for ; Tue, 02 Apr 2024 20:48:35 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1712116114; x=1712720914; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=3QM5RgD/yPYxpmgQZjP2CFSXOSewwExhWFj6N17tFRI=; b=vdg4aru6TWeV5QxnROhe2XSTTx+OpaJhHwZ+ncnAHOPDpfy/R/8KopMNwAAoaRlZUu CxJVx4xtdUFykOadcxeFXueQW0B+suseiOAgN/XPYcpsdDTgmKWihU9v8sDMQ0xccECa SDRXToyIwgzzWgYIKshf/omwfB+ckV0eO4wnQr+OgIW316xnRbZ79HvVY4cuPr2Wh9Zb bHDGGtUm8Mvv5NwAAacid1pzq5bp8DB1Hox/bSIX+XUWhkVtrXn/9xgscQE/ea3Hxeyi SVzc23r5Z5GB9f/tdRVP6TyCAqcYZw46p0OBba8uWMTSXeSBVI81MxyTKz52LN12NziM BGXg== X-Forwarded-Encrypted: i=1; AJvYcCV6CyHpQtgEQroC1XLeC8Fzgz/4vrBh6Y0YOvaosdJo6phlZ7kTkg0/H2N9sL2DtSHvek+4fxdMiEy8JeteMKvmU6jyUQbvw1jU X-Gm-Message-State: AOJu0Yw/doF339dnQgIsRxR9rPD3EJ+QE6X+jbhR6yPyS4sWBNtune60 vvuxJLQ+YcjJwtF9dKLpO/Ew1MfqzTAb/UqHP/Ab1QH/lW9vKe+00gdoe0o/xghFrOcWER7uAT0 wNiyEjNZ9FItXlugLFBwN9/PwErJj+mQD X-Google-Smtp-Source: AGHT+IFfISu283meOA7o+5YUPMJnfHjRKH7AWy+T5lvDkNRG+xlFoRS7CniknYHiRROIntVc3v1xx/Q8wLdukC/cpvc= X-Received: by 2002:a05:651c:203:b0:2d8:3f1c:9978 with SMTP id y3-20020a05651c020300b002d83f1c9978mr99907ljn.17.1712116114106; Tue, 02 Apr 2024 20:48:34 -0700 (PDT) MIME-Version: 1.0 References: <5d588684-17f3-4b96-aafd-9ff6728b2ddd@efficios.com> In-Reply-To: <5d588684-17f3-4b96-aafd-9ff6728b2ddd@efficios.com> Date: Wed, 3 Apr 2024 06:52:33 +0300 Message-ID: To: Erica Bugden Subject: Re: [lttng-dev] Lttng: display active threads in multiple cores. X-BeenThere: lttng-dev@lists.lttng.org X-Mailman-Version: 2.1.39 Precedence: list List-Id: LTTng development list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Zvi Vered via lttng-dev Reply-To: Zvi Vered Cc: lttng-dev@lists.lttng.org Content-Type: multipart/mixed; boundary="===============8832932647651679548==" Errors-To: lttng-dev-bounces@lists.lttng.org Sender: "lttng-dev" --===============8832932647651679548== Content-Type: multipart/alternative; boundary="000000000000cbb3c90615291854" --000000000000cbb3c90615291854 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Hi Erica, Thank you very much for your answer. Can you please tell what is the added value of ftrace (compared to using only lttng) ? Best regards, Zvika On Tue, Apr 2, 2024 at 5:11=E2=80=AFPM Erica Bugden = wrote: > Hello Zvika, > > On 2024-03-29 01:09, Zvi Vered via lttng-dev wrote: > > Hi Christopher, > > > > Thank you very much for your reply. > > Can you please explain what do you mean by ftrace-enabled kernel ? > > I believe what Christopher means by "ftrace-enabled" kernel is that the > Linux kernel has been configured to include ftrace. Both the ftrace > tracer and the LTTng tracer use the same kernel tracepoints to extract > execution information and these tracepoints are included in the kernel > if ftrace is included. > > Most Linux distributions will include ftrace by default. However, you > can check whether this is the case by searching for `tracefs` in > `/proc/filesystems` (assuming it's already mounted) or by trying to > mount `tracefs`. `tracefs` is the filesystem ftrace uses to communicate > with users. > > More details about how to check if ftrace is enabled and how to enable > it if not: > https://wiki.linuxfoundation.org/realtime/documentation/howto/tools/ftrac= e > > The "More Information" section points to the primary sources (Linux > kernel documentation), but I find this page to be a good starting point. > > Best, > Erica > > > > > Best regards, > > Zvika > > > > On Wed, Mar 27, 2024 at 7:32=E2=80=AFPM Christopher Harvey via lttng-de= v > > > wrote: > > > > you can use an ftrace-enabled kernel with lttng (maybe even just > > tracecompass) or perfetto to get that kind of trace > > > > > https://archive.eclipse.org/tracecompass.incubator/doc/org.eclipse.tracec= ompass.incubator.ftrace.doc.user/User-Guide.html > < > https://archive.eclipse.org/tracecompass.incubator/doc/org.eclipse.tracec= ompass.incubator.ftrace.doc.user/User-Guide.html > > > > > > or > > > > https://ui.perfetto.dev/ > > > > On Wed, Mar 27, 2024, at 5:26 AM, Zvi Vered via lttng-dev wrote: > > > Hello, > > > > > > I have an application with 4 threads. > > > I'm required to display on the graph when thread starts working > > till it > > > blocks for the next semaphore. > > > > > > But without using the lttng userspace library. > > > > > > Is it possible ? > > > > > > Thank you, > > > Zvika > > > _______________________________________________ > > > lttng-dev mailing list > > > lttng-dev@lists.lttng.org > > > https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev > > > > _______________________________________________ > > lttng-dev mailing list > > lttng-dev@lists.lttng.org > > https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev > > > > > > > > _______________________________________________ > > lttng-dev mailing list > > lttng-dev@lists.lttng.org > > https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev > --000000000000cbb3c90615291854 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Hi Erica,

Thank you very much for your = answer.=C2=A0
Can you please tell what is the added value of ftra= ce (compared to using only lttng) ?

Best=C2=A0rega= rds,=C2=A0
Zvika=C2=A0


On Tue, Apr 2, 2024 = at 5:11=E2=80=AFPM Erica Bugden <ebugden@efficios.com> wrote:
Hello Zvika,

On 2024-03-29 01:09, Zvi Vered via lttng-dev wrote:
> Hi Christopher,
>
> Thank you very much for your reply.
> Can you please explain what do you mean by ftrace-enabled kernel ?

I believe what Christopher means by "ftrace-enabled" kernel is th= at the
Linux kernel has been configured to include ftrace. Both the ftrace
tracer and the LTTng tracer use the same kernel tracepoints to extract
execution information and these tracepoints are included in the kernel
if ftrace is included.

Most Linux distributions will include ftrace by default. However, you
can check whether this is the case by searching for `tracefs` in
`/proc/filesystems` (assuming it's already mounted) or by trying to mount `tracefs`. `tracefs` is the filesystem ftrace uses to communicate with users.

More details about how to check if ftrace is enabled and how to enable
it if not:
https://wiki.linuxfoundati= on.org/realtime/documentation/howto/tools/ftrace

The "More Information" section points to the primary sources (Lin= ux
kernel documentation), but I find this page to be a good starting point.
Best,
Erica

>
> Best=C2=A0regards,
> Zvika
>
> On Wed, Mar 27, 2024 at 7:32=E2=80=AFPM Christopher Harvey via lttng-d= ev
> <ltt= ng-dev@lists.lttng.org <mailto:lttng-dev@lists.lttng.org>> wrote:
>
>=C2=A0 =C2=A0 =C2=A0you can use an ftrace-enabled kernel with lttng (ma= ybe even just
>=C2=A0 =C2=A0 =C2=A0tracecompass) or perfetto to get that kind of trace=
>
>=C2=A0 =C2=A0 =C2=A0https://archive.eclipse.org/tr= acecompass.incubator/doc/org.eclipse.tracecompass.incubator.ftrace.doc.user= /User-Guide.html <https://archive.eclipse.org/t= racecompass.incubator/doc/org.eclipse.tracecompass.incubator.ftrace.doc.use= r/User-Guide.html>
>
>=C2=A0 =C2=A0 =C2=A0or
>
>=C2=A0 =C2=A0 =C2=A0https://ui.perfetto.dev/ <https://ui.perfetto.= dev/>
>
>=C2=A0 =C2=A0 =C2=A0On Wed, Mar 27, 2024, at 5:26 AM, Zvi Vered via ltt= ng-dev wrote:
>=C2=A0 =C2=A0 =C2=A0 > Hello,
>=C2=A0 =C2=A0 =C2=A0 >
>=C2=A0 =C2=A0 =C2=A0 > I have an application with 4 threads.
>=C2=A0 =C2=A0 =C2=A0 > I'm required to display on the graph when= thread starts working
>=C2=A0 =C2=A0 =C2=A0till it
>=C2=A0 =C2=A0 =C2=A0 > blocks for the next semaphore.
>=C2=A0 =C2=A0 =C2=A0 >
>=C2=A0 =C2=A0 =C2=A0 > But without using the lttng userspace library= .
>=C2=A0 =C2=A0 =C2=A0 >
>=C2=A0 =C2=A0 =C2=A0 > Is it possible ?
>=C2=A0 =C2=A0 =C2=A0 >
>=C2=A0 =C2=A0 =C2=A0 > Thank you,
>=C2=A0 =C2=A0 =C2=A0 > Zvika
>=C2=A0 =C2=A0 =C2=A0 > _____________________________________________= __
>=C2=A0 =C2=A0 =C2=A0 > lttng-dev mailing list
>=C2=A0 =C2=A0 =C2=A0 > lttng-dev@lists.lttng.org <mailto:lttng-dev@lists.lttng.org>
>=C2=A0 =C2=A0 =C2=A0 > https://list= s.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
>=C2=A0 =C2=A0 =C2=A0<https://lists.= lttng.org/cgi-bin/mailman/listinfo/lttng-dev>
>=C2=A0 =C2=A0 =C2=A0_______________________________________________
>=C2=A0 =C2=A0 =C2=A0lttng-dev mailing list
>=C2=A0 =C2=A0 =C2=A0lttng-dev@lists.lttng.org <mailto:lttng-dev@lists.lttng.org><= br> >=C2=A0 =C2=A0 =C2=A0https://lists.lttn= g.org/cgi-bin/mailman/listinfo/lttng-dev
>=C2=A0 =C2=A0 =C2=A0<https://lists.= lttng.org/cgi-bin/mailman/listinfo/lttng-dev>
>
>
> _______________________________________________
> lttng-dev mailing list
> lttng-d= ev@lists.lttng.org
> https://lists.lttng.org/cgi-bin/mailm= an/listinfo/lttng-dev
--000000000000cbb3c90615291854-- --===============8832932647651679548== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ lttng-dev mailing list lttng-dev@lists.lttng.org https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev --===============8832932647651679548==--