From: Grard Roudier Date: Mon, 13 Aug 2001 21:07:50 +0200 (CEST) That's the major problem if we ever want to preserve some ordering in the queuing of SCSI IOs. When DMA mapping operation fails, you simply "stop queueing". Queue freezes and nothing new is executed. DMA wakeup makes you start where you left off. I cannot see any ordering constraints violated by this as a side effect. It is like a "cork" for running scsi commands in the driver. The purpose of the hypothetical kernel thread is to get out of interrupt context if that is deemed necessary. It may not be. Later, David S. Miller davem@redhat.com :.˛mkabzwmb˛mbz_^nrzh&zzޗ++zfh~iz_j:+v)ߣmSy杶ii