<div dir="ltr">Hi Renato,<div><br></div><div style>I'm playing with A15 bots too (running Ubuntu). This is probably what you want to have predictable performance:</div><div style><br></div><div style><div>Disable auto-resetting the CPU scaling governor to ondemand:</div>
<div> sudo update-rc.d -f ondemand remove</div><div><br></div><div>Then add this to /etc/rc.local:</div><div> # Disable power management.</div><div> for cpu in `find /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor`; do</div>
<div> echo performance > $cpu</div><div> done</div><div><br></div></div></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Tue, Feb 19, 2013 at 9:24 AM, David Blaikie <span dir="ltr"><<a href="mailto:dblaikie@gmail.com" target="_blank">dblaikie@gmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><br><div class="gmail_extra"><br><br><div class="gmail_quote"><div><div class="h5">On Tue, Feb 19, 2013 at 7:36 AM, Renato Golin <span dir="ltr"><<a href="mailto:renato.golin@linaro.org" target="_blank">renato.golin@linaro.org</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div>On 19 February 2013 15:16, Arnold Schwaighofer <span dir="ltr"><<a href="mailto:aschwaighofer@apple.com" target="_blank">aschwaighofer@apple.com</a>></span> wrote:<br>
</div><div class="gmail_extra"><div class="gmail_quote"><div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">Do you have a base run with vectorization turned off? So we could see where we are degrading things?<br>
</blockquote><div><br></div></div><div>I wanted to, but after a few failed attempts, I couldn't pass the option to clang to disable vectorization. I don't want to make Galina reconfig the master every time, so I set up a master on my own laptop and will fiddle. But the fastest way I can test, for now, is to run the LNT tests manually with and without vectorization and compare.</div>
<div><br></div><div>I'm not expecting many issues with vectorization, to be honest, but you never know... ;)</div><div><div><br></div><div><br></div><div><br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">
When you say good results, I take it you mean successfully completing the test, not execution time of the resulting binary? Or did you do an analysis of performance, too?<br></blockquote><div><br></div></div><div>Good results because this is the first public test-suite for ARM and we only had 19 errors out of 1104!! And 8 of them are "expected", so it's about 1% or failures.</div>
<div><br></div><div>The non-EH problems should be either mechanical changes on tests, or simple fixes in LLVM, so I'm not expecting a lot of work to get the LNT on the same state on ARM than x86.</div><div>
<br></div><div>I'm not checking performance yet, but the data is being collected here <a href="http://llvm.org/perf/db_default/v4/nts/machine/10" target="_blank">http://llvm.org/perf/db_default/v4/nts/machine/10</a> and should give us some idea on how to proceed from now on on performance measurements.</div>
<div><br></div><div>For now, I'm interested in correctness, so I won't worry too much with those numbers (I've heard I should disable some Turbo mode to make more predictable results, though I only saw one test running at a time, so maybe it was off).</div>
</div></div></div></blockquote><div><br></div></div></div><div>Turbo is a CPU option, not a test suite execution option. Turning it off stops the system from varying the CPU clock based on load (when this feature is enabled it can be a power saving, but it results in varying performance - bad for perf analysis).</div>
<div><br></div><div>Anotehr thing to consider disabling is Address Space Layout Randomization so that you get consistent hashing & other behavior run-over-run.</div><div class="im"><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div dir="ltr"><div class="gmail_extra"><div class="gmail_quote">
<div>Once we have an acceptable state (mostly green, except EH), I'll start worrying about performance.</div></div></div></div></blockquote><div><br></div></div><div>Sounds reasonable.</div><span class="HOEnZb"><font color="#888888"><div>
<br></div><div>
- David <br></div></font></span></div></div></div>
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