<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=us-ascii">
<meta name="Generator" content="Microsoft Word 15 (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;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri",sans-serif;}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:#0563C1;
text-decoration:underline;}
.MsoChpDefault
{mso-style-type:export-only;
font-size:10.0pt;}
@page WordSection1
{size:8.5in 11.0in;
margin:1.0in 1.0in 1.0in 1.0in;}
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="EN-US" link="#0563C1" vlink="#954F72">
<div class="WordSection1">
<p class="MsoNormal">Hi<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Any suggestions on this?<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thanks<o:p></o:p></p>
<p class="MsoNormal">Aprameya<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<div>
<div style="border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in">
<p class="MsoNormal"><b>From:</b> lttng-dev <lttng-dev-bounces@lists.lttng.org> <b>
On Behalf Of </b>Aprameya Rao via lttng-dev<br>
<b>Sent:</b> Thursday, May 28, 2020 9:21 PM<br>
<b>To:</b> lttng-dev@lists.lttng.org<br>
<b>Subject:</b> [EXTERNAL] [lttng-dev] Using LTTng for an application with a single thread per core<o:p></o:p></p>
</div>
</div>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Hi<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I am working on an application where I have a single thread per core (the application is based on top of SPDK -
<a href="https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fspdk.io%2F&data=02%7C01%7Caprameya.rao%40microsoft.com%7C99c722863c7f4b084b2808d80387ae95%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C637263228592195561&sdata=KwAOEkqx%2FIsWtd7zEuntGKZVnqkfUNU4s6VeEXI3jG8%3D&reserved=0">
https://spdk.io/</a>). Ideally, I would like to have a set of buffers allocated per core and since there is a single thread it can write the trace event to this buffer directly with no synchronization. Once the buffer is filled up, the buffer can be given to
LTTng to take care of the persistence.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I’m looking at the LTTng code to figure out what kind of changes would need to be made to support something like this. I imagine it would need to change the ring buffer because the configuration for that while tunable does not have any
mode which does what I want. Am I looking in the right place? If you can provide me to pointers on how I can prototype this with lttng that would be most helpful. Once I have it prototyped, I would be happy to work with you on making these changes back into
LTTng if you feel that this would be of value to other users as well.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Regards<o:p></o:p></p>
<p class="MsoNormal">Aprameya<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
</body>
</html>