<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto"><div dir="ltr"></div><div dir="ltr">I could go into a long description of the 64 core machines we used for hft along with the native thread prioritization we added - along with multiple specialized lock-free queues along with core affinity and numa aware scheduling all to reduce latency and increase throughput. </div><div dir="ltr"><br></div><div dir="ltr">I think a lot of those techniques still apply to vthreads and having it in the platform would benefit everyone. </div><div dir="ltr"><br><blockquote type="cite">On Jan 6, 2023, at 1:27 PM, Ron Pressler <ron.pressler@oracle.com> wrote:<br><br></blockquote></div><blockquote type="cite"><div dir="ltr">
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<font color="#000000" class="">I don’t think that increasing the scheduler’s parallelism would help, nor do I think you’d see a “stop-the-world”, but again, these hypotheses are just not actionable. There’s nothing we can do to address them. When you find a
problem, please report it and we’ll investigate what can be done.</font>
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<div class="">On 6 Jan 2023, at 19:11, Arnaud Masson <<a href="mailto:arnaud.masson@fr.ibm.com" class="">arnaud.masson@fr.ibm.com</a>> wrote:</div>
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<span lang="EN-US" class="">I don’t think having 100% CPU usage on a pod is enough to justify a “stop-the-world” effect on Loom scheduling for the other tasks.<o:p class=""></o:p></span></div>
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<span lang="EN-US" class="">Also 100% is the extreme case, but there can be 75% CPU usage, meaning only 1 carrier left for all other tasks in my example.<o:p class=""></o:p></span></div>
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<span lang="EN-US" class="">Again not a blocker I guess, just have to increase the carrier count to mitigate, but it’s good old native thread sizing again where it should not be really needed.<o:p class=""></o:p></span></div>
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<span lang="EN-US" class="">“Time-sharing would make those expensive tasks complete in a lot more than 10 seconds”:<o:p class=""></o:p></span></div>
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<span lang="EN-US" class="">I understand there would be switching overhead (so it’s slower), but I don’t understand why it would be<span class="Apple-converted-space"> </span><i class="">much</i><span class="Apple-converted-space"> </span>slower if there are
few of them like in my example.<o:p class=""></o:p></span></div>
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<span lang="EN-US" class=""><o:p class=""> </o:p></span></div>
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<span lang="EN-US" class="">thanks<o:p class=""></o:p></span></div>
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<span lang="EN-US" class="">Arnaud<o:p class=""></o:p></span></div>
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