I originally had the Xenomai thread tied to another CPU-Core, hence the subject. The issue happens also if all threads are tied to Core #0.
So the question should read: is memory locking per *thread* necessary? > -----Original Message----- > From: Lange Norbert > Sent: Freitag, 15. Jänner 2021 13:14 > To: Xenomai (xenomai@xenomai.org) <xenomai@xenomai.org> > Subject: is memory locking per core necessary? > > Hello, > > I am trying to track down some spurios relaxes. > > What happens is that I: > - cobalt_init calls mlockall(MCL_CURRENT | MCL_FUTURE); > - allocate and initialize some data in the heap area > - spawn the xenomai-thread > - wait for notification from the xenomai-thread (so that I know, any > initialization there is done) > - call mlockall(MCL_CURRENT | MCL_FUTURE) once more > - notify the xenomai-thread (only now the real work starts) > > Then the Xenomai thread will have spurios relaxes when writing data in the > heap > or bss (reads seem to be fine). > I am a bit confused why this happens, adding a mlockall(MCL_CURRENT | > MCL_FUTURE) in the Xenomai thread fixes the issue. > Note that the locking should happen even before spawning the threads. > > Message I get is: > Jan 15 12:05:19 buildroot kernel: [Xenomai] switching realtime_packet to > secondary mode after exception #14 from user-space at 0x40f3ed (pid 1383) > Code is always a store to heap or bss. > > X86_64 + 4.19.152-cip37-xeno15-static + glibc 2.28 > > /proc/pid/maps: > 00429000-00435000 rw-p 00000000 00:00 0 > 014b5000-014f8000 rw-p 00000000 00:00 0 > [heap] > > /proc/pid/smaps: > 00429000-00435000 rw-p 00000000 00:00 0 > Size: 48 kB > KernelPageSize: 4 kB > MMUPageSize: 4 kB > Rss: 48 kB > Pss: 48 kB > Shared_Clean: 0 kB > Shared_Dirty: 0 kB > Private_Clean: 0 kB > Private_Dirty: 48 kB > Referenced: 48 kB > Anonymous: 48 kB > LazyFree: 0 kB > AnonHugePages: 0 kB > ShmemPmdMapped: 0 kB > Shared_Hugetlb: 0 kB > Private_Hugetlb: 0 kB > Swap: 0 kB > SwapPss: 0 kB > Locked: 48 kB > THPeligible: 0 > VmFlags: rd wr mr mw me lo ac > 014b5000-014f8000 rw-p 00000000 00:00 0 > [heap] > Size: 268 kB > KernelPageSize: 4 kB > MMUPageSize: 4 kB > Rss: 268 kB > Pss: 268 kB > Shared_Clean: 0 kB > Shared_Dirty: 0 kB > Private_Clean: 0 kB > Private_Dirty: 268 kB > Referenced: 268 kB > Anonymous: 268 kB > LazyFree: 0 kB > AnonHugePages: 0 kB > ShmemPmdMapped: 0 kB > Shared_Hugetlb: 0 kB > Private_Hugetlb: 0 kB > Swap: 0 kB > SwapPss: 0 kB > Locked: 268 kB > THPeligible: 0 > VmFlags: rd wr mr mw me lo ac > > Mit besten Grüßen / Kind regards > > NORBERT LANGE ________________________________ This message and any attachments are solely for the use of the intended recipients. They may contain privileged and/or confidential information or other information protected from disclosure. If you are not an intended recipient, you are hereby notified that you received this email in error and that any review, dissemination, distribution or copying of this email and any attachment is strictly prohibited. If you have received this email in error, please contact the sender and delete the message and any attachment from your system. ANDRITZ HYDRO GmbH Rechtsform/ Legal form: Gesellschaft mit beschränkter Haftung / Corporation Firmensitz/ Registered seat: Wien Firmenbuchgericht/ Court of registry: Handelsgericht Wien Firmenbuchnummer/ Company registration: FN 61833 g DVR: 0605077 UID-Nr.: ATU14756806 Thank You ________________________________
