> - Some time ago I observed that the kernel reported soft lockups > because of spin_lock() calls inside a completion handler. These > spinlocks were not locked in any other context than the completion > handler itself. And the lockups disappeared after having replaced the > spin_lock() calls by spin_lock_irqsave(). Can it be concluded from > this observation that completion handlers are not always invoked from > interrupt context ?
Did you get a soft lockup report or a lockdep report? Anyway, the very next paragraph of the documentation I quoted says: The context in which completion event and asynchronous event callbacks run is not defined. Depending on the low-level driver, it may be process context, softirq context, or interrupt context. Upper level protocol consumers may not sleep in a callback. So yes, it is possible that a completion callback gets called in non-interrupt context. However as far as I know, at least mthca and mlx4 only call completion callbacks from the interrupt handler. But without the actual code in question it's hard to know what the real problem was. - R. -- Roland Dreier <rola...@cisco.com> || For corporate legal information go to: http://www.cisco.com/web/about/doing_business/legal/cri/index.html -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
