On Tue, Jun 14, 2011 at 00:31:50 +0300, Kostik Belousov wrote: > On Mon, Jun 13, 2011 at 09:21:02PM +0000, Justin T. Gibbs wrote: > > Author: gibbs > > Date: Mon Jun 13 21:21:02 2011 > > New Revision: 223061 > > URL: http://svn.freebsd.org/changeset/base/223061 > > > > Log: > > Fix a couple of race conditions in devstat(9) initialization. > > > > In devstat_new_entry(), there is no need to initialize the queue > > and the mutex in this function. There are ways to do static > > initialization on both, so use STAILQ_HEAD_INITIALIZER and > > MTX_SYSINIT to initialize the queue and the mutex. > > > > In devstat_alloc(), use an atomic test and set routine to guard > > making our entry in /dev. Using just a plain static variable > > creates a race condition on multiprocessor machines. If you > > attempt to create a second entry in devfs, the kernel will panic. > Devfs returns an error if MAKEDEV_CHECKNAME flag is supplied and > attempt is made to create the existing node. The static guard is > still useful, since make_dev() call is costly, but you can remove > the atomic, since the race should be of limited scope.
Done, thanks for the suggestion! Ken -- Kenneth Merry [email protected] _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "[email protected]"
