cvs commit: src/sys/i386/i386 pmap.c src/sys/kern subr_witness.c

[John Baldwin]

jhb         2004-08-04 20:31:19 UTC

  FreeBSD src repository

  Modified files:
    sys/i386/i386        pmap.c 
    sys/kern             subr_witness.c 
  Log:
  Remove a potential deadlock on i386 SMP by changing the lazypmap ipi and
  spin-wait code to use the same spin mutex (smp_tlb_mtx) as the TLB ipi
  and spin-wait code snippets so that you can't get into the situation of
  one CPU doing a TLB shootdown to another CPU that is doing a lazy pmap
  shootdown each of which are waiting on each other.  With this change, only
  one of the CPUs would do an IPI and spin-wait at a time.
  
  Revision  Changes    Path
  1.493     +2 -8      src/sys/i386/i386/pmap.c
  1.178     +0 -1      src/sys/kern/subr_witness.c