On Tue, 18 Oct 2011, Emmanuel Dreyfus wrote:
As I understand, at VFS level, VOP_STRATEGY(9) is used for I/O to block
devices. Where does that name comes from?
Block devices use the `strategy()' routines to schedule operations
because, unlike character devices which typically immediately post the
write opertion to the hardware, they used to go through disksort() so the
elevator algorithm could be used to optimize disk access. Hence the
strategy() routine did not necessarily start the I/O operation, it would
usually add it to a work queue.
Eduardo
