[v4,0/5] enhance lock debugging

Message

Jürgen Groß Sept. 9, 2019, 2:31 p.m. UTC

While hunting a locking problem in my core scheduling series I have
added some debugging aids to spinlock handling making it easier to
find the root cause for the problem.

Making use of the already existing lock profiling and enhancing it a
little bit produces some really valuable diagnostic data e.g. when a
NMI watchdog is triggering a crash.

Changes in V4:
- some comments by Jan Beulich addressed
- replaced patch 5 with another approach to make lock names unique

Changes in V3:
- rebase to current staging (after realizing that patch 4 still
  applied, but resulting in patching a wrong function)

Changes in V2:
- multiple comments addressed
- added patch 5

Juergen Gross (5):
  xen/spinlocks: in debug builds store cpu holding the lock
  xen: add new CONFIG_DEBUG_LOCKS option
  xen: print lock profile info in panic()
  xen: modify lock profiling interface
  xen: add function name to lock profiling data

 tools/libxc/xc_misc.c       |   1 +
 tools/misc/xenlockprof.c    |  17 +---
 xen/Kconfig.debug           |  10 ++-
 xen/arch/arm/xen.lds.S      |  13 ++--
 xen/arch/x86/domain.c       |   2 +-
 xen/arch/x86/xen.lds.S      |  13 ++--
 xen/common/domain.c         |   4 +-
 xen/common/keyhandler.c     |   2 +-
 xen/common/spinlock.c       | 185 ++++++++++++++++++++++++++++++++------------
 xen/common/sysctl.c         |   2 +-
 xen/drivers/char/console.c  |   4 +-
 xen/include/public/sysctl.h |  11 +--
 xen/include/xen/spinlock.h  |  75 +++++++++++-------
 13 files changed, 221 insertions(+), 118 deletions(-)