On 2020-09-03 21:51, Nilesh Javali wrote: > This patch tracks number of IOCB resources used in the IO fast path. > If the number of used IOCBs reach a high water limit, driver would > return the IO as busy and let upper layer retry. This prevents over > subscription of IOCB resources where any future error recovery command > is unable to cut through. > Enable IOCB throttling by default. Please use the block layer reserved tag mechanism instead of adding a mechanism that is (a) racy and (b) triggers cache line ping-pong. QT: The Block layer reserve tag does fit resource we're tracking. The reserve tag is per command. The IOCB resource is adapter specific behind all commands.
