<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Interesting reading, please post a link to where to find the code and data examples to backup this findings, and<div>allow for others to repeat your experiments.</div><div>/Tony</div><div><br><div><div>On 27 nov 2011, at 00:41, Ian wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div>HI all,<br><br>I have written a program in Erlang, that has 4 async processes in "string of pearls" formation. The results were surprisingly quick, so I threw a huge input file at it to see what would happen.<br><br>Expected one process (the 2nd) to require more cpu than the others. As the limiting factor it would max out one core to 100%. The rest would be less, constant and approx equal. But this isn't what happened.<br><br>Three cores were loaded about 40-50%. The 4th core was left at virtually idle (2%). Job ran in 25 seconds, average load about 32%.<br><br>So I moved the input and output files to a ram disk. And got much the same result. It ran in 22 seconds, and loaded 3 cores, one 50% and varying, the others 30% or so, Overall 30%.<br><br>Then I tried with +A 5 and the RAM drive. Now it loaded one core 60 to 90%, and a a second about 40-60%. The other two cores flickered a little and settled back to background! Job ran in 23 seconds, average load about 30%.<br><br>So I guess that disk was not limiting the speed. But what was? I never got the load over 35%.<br><br>Can some kind person please explain the scheduling algorithm in the VM, and explain these results. They seem very odd to me.<br><br>Thanks<br><br>Ian<br><br><br><br><br><br><br><br><br>_______________________________________________<br>erlang-questions mailing list<br><a href="mailto:erlang-questions@erlang.org">erlang-questions@erlang.org</a><br>http://erlang.org/mailman/listinfo/erlang-questions<br></div></blockquote></div><br><div>
<span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; "><div><span class="Apple-style-span" style="color: rgb(51, 51, 51); font-family: Geneva, Arial, Helvetica, sans-serif; font-size: 12px; ">"Installing applications can lead to corruption over time. </span><span class="Apple-style-span" style="color: rgb(51, 51, 51); font-family: Geneva, Arial, Helvetica, sans-serif; font-size: 12px; ">Applications gradually write over each other's libraries, partial upgrades occur, user and system errors happen, and minute changes may be unnoticeable and difficult to fix"</span></div><div><span class="Apple-style-span" style="color: rgb(51, 51, 51); font-family: Geneva, Arial, Helvetica, sans-serif; font-size: 12px; "><br></span></div></span><br class="Apple-interchange-newline">
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