Test on an AWS server: Intel(R) Xeon(R) Platinum 8275CL CPU @ 3.00GHz (16 cores)
Running webtooling with d8 Here is the v8.gc tracing data: [image: baseline.png] [image: 15worker.png] Raw tracing log files: https://drive.google.com/drive/folders/1NRQCjNQ5x9RDHA0AVvTOr8neuARyheq-?usp=sharing For the concurrent marking speed, I simply sum up the KB and ms in the trace log and divide them (KB/ms), For each worker: baseline: 640.5, 669.86, 684.72 15 workers:508.91, 515.51, 503.51 Maybe it's better to replace the fixed kMaxTasks with core number? Just like what parallel compaction do. https://source.chromium.org/chromium/chromium/src/+/main:v8/src/heap/mark-compact.cc;l=472;bpv=1;bpt=0?q=NumberOfParallelCompactionTasks&ss=chromium%2Fchromium%2Fsrc Regards, Jianxiao On Wednesday, June 22, 2022 at 2:03:30 AM UTC+8 Michael Lippautz wrote: > On Tue, Jun 21, 2022 at 11:36 AM Jianxiao Lu <[email protected]> wrote: > >> Thanks for the explanation. The second screenshot is 1520ms~1560ms in >> fact. The snapshots were taken from the first major gc running webtooling. >> Because I believe the first major gcs are relatively predictable and >> consistent. (Maybe I am wrong). >> >> I will check with your suggestion later. Does the gc-tracer already have >> something to record the mark-bytes/ms ? Or I need to try to implement one? >> > > --trace-concurrent-marking will log concurrently marked bytes and > timespans which can be used to compute the speed. Any custom logging will > also do though. > > -Michael > > >> >> Thanks, >> Jianxiao >> >> On Tuesday, June 21, 2022 at 3:08:10 PM UTC+8 [email protected] wrote: >> >>> On Tue, Jun 21, 2022 at 8:33 AM Jianxiao Lu <[email protected]> wrote: >>> >>>> >>>> https://source.chromium.org/chromium/chromium/src/+/main:v8/src/heap/concurrent-marking.h;l=59?q=kMaxTasks&sq=&ss=chromium >>>> >>>> The code comments above seems out of date. So I wonder if this >>>> limitation is intentional or just no be updated in time. >>>> >>>> Here is a snapshot in webtooling (d8). >>>> >>>> [image: 7.png] >>>> >>>> After I tuned the worker number( >>>> https://chromium-review.googlesource.com/c/v8/v8/+/3711496): >>>> [image: 15.png] >>>> >>>> Seems that we can benefit from more worker? >>>> >>> >>> This really depends on what the average size of the heap is.The numbers >>> were chosen as a compromise between small and large heaps and low-end vs >>> desktop devices. Also, the algorithm doesn't scale linearly but there's >>> smaller trade offs here and there which add up as the # tasks are increased. >>> >>> Did the absolute time actually improve? I see 1280ms-1340ms in the first >>> screenshot vs 1520ms-1580ms. You could check marked bytes/s as a proxy of >>> whether the helper tasks are still efficient or not. >>> >>> -Michael >>> >>> >>>> -- >>>> -- >>>> v8-dev mailing list >>>> [email protected] >>>> http://groups.google.com/group/v8-dev >>>> --- >>>> You received this message because you are subscribed to the Google >>>> Groups "v8-dev" group. >>>> To unsubscribe from this group and stop receiving emails from it, send >>>> an email to [email protected]. >>>> To view this discussion on the web visit >>>> https://groups.google.com/d/msgid/v8-dev/2944463a-a964-40a9-91f4-fba7a74debe8n%40googlegroups.com >>>> >>>> <https://groups.google.com/d/msgid/v8-dev/2944463a-a964-40a9-91f4-fba7a74debe8n%40googlegroups.com?utm_medium=email&utm_source=footer> >>>> . >>>> >>> -- >> -- >> v8-dev mailing list >> [email protected] >> http://groups.google.com/group/v8-dev >> --- >> You received this message because you are subscribed to the Google Groups >> "v8-dev" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> > To view this discussion on the web visit >> https://groups.google.com/d/msgid/v8-dev/3e8a9fd6-0a7f-424a-843c-9d3be714ecebn%40googlegroups.com >> >> <https://groups.google.com/d/msgid/v8-dev/3e8a9fd6-0a7f-424a-843c-9d3be714ecebn%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> > -- -- v8-dev mailing list [email protected] http://groups.google.com/group/v8-dev --- You received this message because you are subscribed to the Google Groups "v8-dev" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/v8-dev/50b7b577-3304-4227-ae7c-1b59f8d4690bn%40googlegroups.com.
