<html><head><meta http-equiv="Content-Type" content="text/html charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;"><br><div><div>On 6 May 2014, at 11:13 am, Rik Cabanier <<a href="mailto:cabanier@gmail.com">cabanier@gmail.com</a>> wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div dir="ltr">On Mon, May 5, 2014 at 5:52 PM, Simon Fraser <span dir="ltr"><<a href="mailto:simon.fraser@apple.com" target="_blank">simon.fraser@apple.com</a>></span> wrote:<br><div class="gmail_extra"><div class="gmail_quote">
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div style="word-wrap:break-word">It allows attackers to know even more about my system, exposing more data for fingerprinting.</div>
</blockquote><div><br></div><div>People can already approximate this today. Approximations are fuzzy so this might hurt performance if you're not a popular platform or change how the browser implements workers.</div></div></div></div></blockquote><div><br></div><div>There is a difference between approximation and clear detection. During discussion of a related feature on the WebGL list (for exposing the GPU information to the page), I noted at the time that it would allow any page in the world to detect you'd spent X thousand dollars on a Mac Pro in the last 30 days. Being able to detect the number of cores provides more info - e.g. you spent X + Y thousand dollars for the upgrade.</div><div><br></div><div>"Let's not show that user ads for vacations in Compton... let's show them the Bahamas instead."</div><br><blockquote type="cite"><div dir="ltr"><div class="gmail_extra"><div class="gmail_quote"><div>
</div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div style="word-wrap:break-word"><div>Do you really want a page to know that you have a fancy-pants 24-core Mac Pro rather than a little Mac mini?</div>
</div></blockquote><div><br></div><div>Yes!</div><div>If I have 24 cores ready to do work and the page can put them to use, I would like it to do so.</div><div>At the same time, if I just have a old mac mini, I don't want the page to launch 24 workers as that will exhaust my memory and cause contention. </div>
</div></div></div></blockquote><br></div><div>But as Oliver said, maybe I don't want the page to use all cores.</div><div><br></div><div>Dean</div><div><br></div><div><br></div><br></body></html>