https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=219399
--- Comment #121 from Nils Beyer <n...@renzel.net> --- (In reply to Don Lewis from comment #119) > This gives mfence() some memory loads to wait for, which allows the data to > be migrated from the core A cache. With this change, I no longer get any > segfaults. confirmed - with that change, I haven't gotten any segfaults in 500 passes. Though, there is a discrepancy in how many passes each core has absolved: --------------------------------------------------------------------------- [...] 412: Tue Jul 25 15:19:00 CEST 2017: OK 405: Tue Jul 25 15:19:01 CEST 2017: OK 402: Tue Jul 25 15:19:01 CEST 2017: OK 420: Tue Jul 25 15:19:01 CEST 2017: OK 410: Tue Jul 25 15:19:01 CEST 2017: OK 406: Tue Jul 25 15:19:01 CEST 2017: OK 410: Tue Jul 25 15:19:01 CEST 2017: OK 414: Tue Jul 25 15:19:01 CEST 2017: OK 410: Tue Jul 25 15:19:01 CEST 2017: OK 409: Tue Jul 25 15:19:02 CEST 2017: OK 413: Tue Jul 25 15:19:02 CEST 2017: OK 423: Tue Jul 25 15:19:02 CEST 2017: OK 397: Tue Jul 25 15:19:02 CEST 2017: OK 411: Tue Jul 25 15:19:02 CEST 2017: OK 401: Tue Jul 25 15:19:02 CEST 2017: OK 421: Tue Jul 25 15:19:02 CEST 2017: OK 438: Tue Jul 25 15:19:02 CEST 2017: OK 427: Tue Jul 25 15:19:02 CEST 2017: OK 406: Tue Jul 25 15:19:02 CEST 2017: OK --------------------------------------------------------------------------- In my eyes, each core is performing the same workload and should therefore be at the same pass number. Maybe I'm completely wrong. But isn't that something you've observed, too, is it? > Ryzen bug? Just more aggressive prefetching? I don't know ... It's a rather difficult question: if CPU A executes something without segfaults; and CPU B throws segfaults using the same executable, does that automatically mean that CPU B is doing it all wrongly? Or does it rather mean CPU B is not 100% compatible to CPU A and therefore needs an appropiate executable? I ask because I wonder if that's something that should be told to AMD tech support - particularly because I have an open ticket there... -- You are receiving this mail because: You are the assignee for the bug. _______________________________________________ freebsd-bugs@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-bugs To unsubscribe, send any mail to "freebsd-bugs-unsubscr...@freebsd.org"
