1. 12 7月, 2007 1 次提交
    • M
      [AF_UNIX]: Rewrite garbage collector, fixes race. · 1fd05ba5
      Miklos Szeredi 提交于
      Throw out the old mark & sweep garbage collector and put in a
      refcounting cycle detecting one.
      
      The old one had a race with recvmsg, that resulted in false positives
      and hence data loss.  The old algorithm operated on all unix sockets
      in the system, so any additional locking would have meant performance
      problems for all users of these.
      
      The new algorithm instead only operates on "in flight" sockets, which
      are very rare, and the additional locking for these doesn't negatively
      impact the vast majority of users.
      
      In fact it's probable, that there weren't *any* heavy senders of
      sockets over sockets, otherwise the above race would have been
      discovered long ago.
      
      The patch works OK with the app that exposed the race with the old
      code.  The garbage collection has also been verified to work in a few
      simple cases.
      Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      1fd05ba5
  2. 11 7月, 2007 39 次提交