Elias Oltmanns wrote: > Tejun Heo <htejun@xxxxxxxxx> wrote: >> Elias Oltmanns wrote: >>> This proves that piix_qc_defer() has declined the same command 100 >>> times in succession. However, this will only happen if the status of >>> all the commands enqueued for one port hasn't changed in the >>> meantime. This suggests to me that the threads scheduled for command >>> execution and completion aren't served for some reason. Any ideas? >> Blocked counts of 1 will cause busy looping because when blk_run_queue() >> returns because it's recursing too deep, it schedules unplug work right >> away, so it will easily loop 100 times. Max blocked counts should be >> adjusted to two (needs some testing before actually submitting the >> change). But that still shouldn't cause any lock up. What happens if >> you remove the 100 times limit? Does the machine hang on IO? > > Yes, it does. In fact, I had already verified that before sending the > previous email. Hmmm.... it's supposed not to lock up although it can cause busy wait. I'll test it tomorrow. Thanks. -- tejun - To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
