cvs commit: src/sys/vm uma_core.c

[Bosko Milekic]

bmilekic    2004-06-23 21:59:03 UTC

  FreeBSD src repository

  Modified files:
    sys/vm               uma_core.c 
  Log:
  Make uma_mtx MTX_RECURSE.  Here's why:
  
  The general UMA lock is a recursion-allowed lock because
  there is a code path where, while we're still configured
  to use startup_alloc() for backend page allocations, we
  may end up in uma_reclaim() which calls zone_foreach(zone_drain),
  which grabs uma_mtx, only to later call into startup_alloc()
  because while freeing we needed to allocate a bucket.  Since
  startup_alloc() also takes uma_mtx, we need to be able to
  recurse on it.
  
  This exact explanation also added as comment above mtx_init().
  
  Trace showing recursion reported by: Peter Holm <peter-at-holm.cc>
  
  Revision  Changes    Path
  1.97      +11 -1     src/sys/vm/uma_core.c