cvs commit: src/sys/kern kern_descrip.c

[Robert Watson]

rwatson     2004-11-28 14:37:17 UTC

  FreeBSD src repository

  Modified files:
    sys/kern             kern_descrip.c 
  Log:
  Don't acquire Giant before calling closef() in close() (and elsewhere);
  instead acquire it conditionally in closef() if it is required for
  advisory locking.  This removes Giant from the close() path of sockets
  and pipes (and any other objects that don't acquire Giant in their
  fo_close path, such as kqueues).  Giant will still be acquired twice for
  vnodes -- once for advisory lock teardown, and a second time in the
  fo_close method.  Both Poul-Henning and I believe that the advisory lock
  teardown code can be moved into the vn_closefile path shortly.
  
  This trims a percent or two off the cost of most non-vnode close
  operations on SMP, but has a fairly minimal impact on UP where the cost
  of a single mutex operation is pretty low.
  
  Revision  Changes    Path
  1.258     +7 -7      src/sys/kern/kern_descrip.c