[RTEMS Project] #4922: QEMU delivers back-to-back timer ticks after task switches

[RTEMS trac]

#4922: QEMU delivers back-to-back timer ticks after task switches
---------------------------+------------------------
  Reporter:  Kinsey Moore  |      Owner:  (none)
      Type:  defect        |     Status:  new
  Priority:  normal        |  Milestone:  Indefinite
 Component:  tool/rsb      |    Version:  6
  Severity:  normal        |   Keywords:
Blocked By:                |   Blocking:
---------------------------+------------------------
 A selection of tests in the RTEMS testsuite will fail consistently or
 intermittently when running under QEMU while they pass consistently on
 real hardware or more accurate simulators. This is due to QEMU getting
 context-switched out on the host system and when it gets more run time it
 delivers all outstanding clock ticks as quickly as possible according to
 the wall clock. Naturally, this is more severe on heavily loaded systems.
 The tests that fail in this manner are heavily dependent on timing and
 inter-tick processing to verify their correct operation.

 The tests known to fail in this manner on ARM and AArch64 BSPs are at
 least:
 psx12
 psxclock
 psxtimes01
 psxualarm
 rtmonuse
 rtmonusxtimes01
 smpclock01
 smpfatal01
 smpfatal03
 smpmrsp01
 smpmutex01
 smppsxmutex01
 smpschedaffinity01
 smpschedaffinity02
 smpschededf01
 smpschededf03
 smpscheduler04
 smpthreadpin01
 sp04
 sp20
 sp68
 sp69
 sp71
 spcpucounter01
 spedfsched02
 spedfsched04
 spintrcritical01
 spintrcritical02
 spintrcritical03
 spintrcritical04
 spintrcritical05
 spintrcritical06
 spintrcritical07
 spintrcritical08
 spintrcritical09
 spintrcritical10
 spintrcritical11
 spintrcritical12
 spintrcritical13
 spintrcritical14
 spintrcritical15
 spintrcritical16
 spintrcritical17
 spintrcritical18
 spintrcritical19
 spintrcritical20
 spintrcritical21
 spintrcritical22
 spintrcritical23
 spintrcritical24
 sprmsched01
 sptimecounter01
 sptimecounter02
 sptimecounter04
 ttest02

 This issue does not exist to rectify the situation with QEMU so much as to
 document the issue so that it can be referenced from non-pass expected
 test outcomes for those affected BSPs that are dedicated to the QEMU
 platform.

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Ticket URL: <http://devel.rtems.org/ticket/4922>
RTEMS Project <http://www.rtems.org/>
RTEMS Project