On Sun, Oct 28, 2007 at 09:38:55PM +0000, Alan Cox wrote: > > It doesn't require the system to detect it, only mandate what to return > > if it does detect it. > > We should be detecting at least the obvious case. What is the obvious case? A task that has never called clone()? > If SYSV only spots simple AB - BA deadlocks or taking the same lock twice > yourself then that ought to be sufficient for us too. You can't deadlock against yourself -- either with POSIX locks or BSD locks (POSIX simple upgrades/downgrades the lock; each byte in a file can only be in either read-locked state or write-locked state for a given process. BSD locks release the lock and wake all waiters before attempting to acquire the lock in its new state). In my other post, I showed a simple AB-BA deadlock that can't be easily detected. -- Intel are signing my paycheques ... these opinions are still mine "Bill, look, we understand that you're interested in selling us this operating system, but compare it to ours. We can't possibly take such a retrograde step." - To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
