<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<meta name="Generator" content="Microsoft Word 14 (filtered medium)">
<style><!--
/* Font Definitions */
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:Tahoma;
panose-1:2 11 6 4 3 5 4 4 2 4;}
@font-face
{font-family:Consolas;
panose-1:2 11 6 9 2 2 4 3 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0cm;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Times New Roman","serif";}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
p.MsoAcetate, li.MsoAcetate, div.MsoAcetate
{mso-style-priority:99;
mso-style-link:"Texte de bulles Car";
margin:0cm;
margin-bottom:.0001pt;
font-size:8.0pt;
font-family:"Tahoma","sans-serif";}
p.MsoListParagraph, li.MsoListParagraph, div.MsoListParagraph
{mso-style-priority:34;
margin-top:0cm;
margin-right:0cm;
margin-bottom:0cm;
margin-left:36.0pt;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Times New Roman","serif";}
span.EmailStyle17
{mso-style-type:personal-reply;
font-family:"Calibri","sans-serif";
color:#1F497D;}
span.TextedebullesCar
{mso-style-name:"Texte de bulles Car";
mso-style-priority:99;
mso-style-link:"Texte de bulles";
font-family:"Tahoma","sans-serif";
mso-fareast-language:FR-CA;}
.MsoChpDefault
{mso-style-type:export-only;
font-family:"Calibri","sans-serif";
mso-fareast-language:EN-US;}
@page WordSection1
{size:612.0pt 792.0pt;
margin:72.0pt 90.0pt 72.0pt 90.0pt;}
div.WordSection1
{page:WordSection1;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
</head>
<body lang="FR-CA" link="blue" vlink="purple">
<div class="WordSection1">
<p class="MsoNormal"><b><span lang="FR" style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">De :</span></b><span lang="FR" style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> Randy Wijnants [mailto:randy@tty32.org]
<br>
<b>Envoyé :</b> 27 mai 2014 06:34<br>
<br>
<o:p></o:p></span></p>
<div>
<div>
<p class="MsoNormal"><span lang="EN-CA" style="color:#1F497D">> </span><span lang="EN-CA">Changed the dashed arrows into dotted arrows.<o:p></o:p></span></p>
</div>
<div>
<p class="MsoNormal"><span lang="EN-CA" style="color:#1F497D">></span><span lang="EN-CA"><o:p> </o:p></span></p>
</div>
<div>
<p class="MsoNormal"><span lang="EN-CA" style="color:#1F497D">> </span><span lang="EN-CA">Is the arrow running from the lttng session daemon to liblttng-ust valid?<span style="color:#1F497D"><o:p></o:p></span></span></p>
<p class="MsoNormal"><span lang="EN-CA" style="color:#1F497D">></span><span lang="EN-CA"> Does the liblttng-ust always write to the shared memory buffer or only if the session daemon instructs it to (via which interface?)<o:p></o:p></span></p>
</div>
<div>
<p class="MsoNormal"><span lang="EN-CA" style="color:#1F497D">> </span><span lang="EN-CA">And what is the interface used between the session
<span style="color:#1F497D">a</span>n<span style="color:#1F497D">d</span> consumer daemon?<o:p></o:p></span></p>
</div>
<div>
<p class="MsoNormal"><span lang="EN-CA" style="color:#1F497D">></span><span lang="EN-CA"><o:p> </o:p></span></p>
</div>
<div>
<p class="MsoNormal"><span lang="EN-CA" style="color:#1F497D">> </span>New version: <o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><span lang="EN-CA" style="color:#1F497D">> </span><a href="--ESFSECEV-TY3011----------------------------" target="_blank">http://tty32.org/Logging%20configuration2.png</a><o:p></o:p></p>
</div>
<p class="MsoNormal"><span lang="EN-CA" style="color:#1F497D">></span><o:p> </o:p></p>
<div>
<div>
<div>
<div>
<div>
<p class="MsoNormal"><span lang="EN-CA" style="color:#1F497D">> </span><span style="font-size:10.0pt;font-family:"Arial","sans-serif"">Randy Wijnants.<o:p></o:p></span></p>
</div>
</div>
</div>
</div>
<p class="MsoNormal" style="margin-bottom:12.0pt"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal" style="margin-bottom:12.0pt"><span lang="EN-CA" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"> Unless I’m mistaken, when a session daemon disables a channel, for instance, it asks liblttng-ust to turn off the
immediate value test in the registered applications (each tracepoint entry is guarded by an immediate value test which is controlled by changing a single byte). That’s the principle, anyway. I haven’t actually followed this through the tangle of LTTng’s
code.<o:p></o:p></span></p>
<p class="MsoNormal" style="margin-bottom:12.0pt"><span lang="EN-CA" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"> Rest assured that if liblttng-ust writes to a channel’s buffer, it’s because the event was enabled at the time.<o:p></o:p></span></p>
<p class="MsoNormal" style="margin-bottom:12.0pt"><span lang="EN-CA" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"> I know the consumer daemon(s) read(s) /run/lttng/lttng-session.pid (or $HOME/.lttng/lttng-session.pid) to reach
the session daemon. I think the session daemon uses the /run/lttng/ustconsumerd64 (or $HOME/.lttng/ustconsumerd64; 32-bit versions may also exist) socket to send commands to the consumer daemon(s).<o:p></o:p></span></p>
<p class="MsoNormal" style="margin-bottom:12.0pt"><span lang="EN-CA" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"> About the only things the diagram is missing now are:<o:p></o:p></span></p>
<p class="MsoNormal" style="margin-bottom:12.0pt"><span lang="EN-CA" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">* the lttng-relayd daemon (which completes the “Network destination / streaming” box);<o:p></o:p></span></p>
<p class="MsoNormal" style="margin-bottom:12.0pt"><span lang="EN-CA" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">* the add-context command (easily put beside enable-channel and enable-event); and<o:p></o:p></span></p>
<p class="MsoNormal" style="margin-bottom:12.0pt"><span lang="EN-CA" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">* the buffers-global / buffers-pid / buffers-uid alternative (could be put opposite the output TYPE at the Buffer’s
top right).<o:p></o:p></span></p>
<p class="MsoNormal" style="margin-bottom:12.0pt"><span lang="EN-CA" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"> Change:<o:p></o:p></span></p>
<p class="MsoNormal" style="margin-bottom:12.0pt"><span lang="EN-CA" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">* “LTTv” into “LTTV”<o:p></o:p></span></p>
<p class="MsoNormal" style="margin-bottom:12.0pt"><span lang="EN-CA" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">* “Eclipse” into “Eclipse TMF”<o:p></o:p></span></p>
<p class="MsoNormal" style="margin-bottom:12.0pt"><span lang="EN-CA" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">* “tracefilesize” into “tracefile-size”<o:p></o:p></span></p>
<p class="MsoNormal" style="margin-bottom:12.0pt"><span lang="EN-CA" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">* “commandline” into “command line”<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:Consolas;color:#1F497D">Daniel U. Thibault<br>
Protection des systèmes et contremesures (PSC) | Systems Protection & Countermeasures (SPC)<br>
Cyber sécurité pour les missions essentielles (CME) | Mission Critical Cyber Security (MCCS)<br>
R & D pour la défense Canada - Valcartier (RDDC Valcartier) | Defence R&D Canada - Valcartier (DRDC Valcartier)<br>
2459 route de la Bravoure<br>
Québec QC G3J 1X5<br>
CANADA<br>
Vox</span><span style="font-size:10.5pt;font-family:Consolas;color:#1F497D;mso-fareast-language:EN-US"> </span><span style="font-size:11.0pt;font-family:Consolas;color:#1F497D">: (418) 844-4000 x4245<br>
Fax</span><span style="font-size:10.5pt;font-family:Consolas;color:#1F497D;mso-fareast-language:EN-US"> </span><span style="font-size:11.0pt;font-family:Consolas;color:#1F497D">: (418) 844-4538<br>
</span><span style="font-size:11.0pt;font-family:Consolas;color:#1F497D">NAC : </span>
<span lang="EN-CA" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><a href="http://www.travelgis.com/map.asp?addr=918V%20QSDJ"><span lang="FR-CA" style="font-size:10.0pt;font-family:"Courier New"">918V QSDJ</span></a></span><span lang="EN-CA" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">
</span><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><</span><u><span style="font-size:10.0pt;font-family:"Courier New";color:blue">http://www.travelgis.com/map.asp?addr=918V%20QSDJ</span></u><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">></span><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><br>
</span><span style="font-size:11.0pt;font-family:Consolas;color:#1F497D">Gouvernement du Canada | Government of Canada<br>
</span><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><</span><span lang="EN-CA" style="font-size:10.0pt;font-family:"Courier New";color:blue"><a href="http://www.valcartier.drdc-rddc.gc.ca/"><span lang="FR-CA">http://www.valcartier.drdc-rddc.gc.ca/</span></a></span><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">></span><span style="font-size:10.5pt;font-family:Consolas;color:#1F497D"><o:p></o:p></span></p>
</div>
</div>
</div>
</body>
</html>