A block layer introduction part 1: the bio layer

Posted Oct 26, 2017 4:06 UTC (Thu) by Cyberax (✭ supporter ✭, #52523)
In reply to: A block layer introduction part 1: the bio layer by neilbrown
Parent article: A block layer introduction part 1: the bio layer

Crawl out of the out-of-memory situation to resolve the deadlock.

A block layer introduction part 1: the bio layer

Posted Oct 26, 2017 5:57 UTC (Thu) by neilbrown (subscriber, #359) [Link] (2 responses)

> Crawl out of the out-of-memory situation to resolve the deadlock.

Surely it is better to design the code to be dead-lock free. It isn't that hard once the problem is understood. (and if the problem isn't understood, then a workaround like that might not be a complete solution).

A block layer introduction part 1: the bio layer

Posted Oct 26, 2017 6:04 UTC (Thu) by Cyberax (✭ supporter ✭, #52523) [Link] (1 responses)

I'm confused. Can the abovementioned scenario deadlock with the current bio layer?

A block layer introduction part 1: the bio layer

Posted Oct 27, 2017 2:01 UTC (Fri) by neilbrown (subscriber, #359) [Link]

> Can the abovementioned scenario deadlock with the current bio layer?

No, hence the parenthetical comment (newer code will have sorted this to the end of the list, to help avoid the deadlock).
Providing drivers which split bios only process one of them and submit the other directly to generic_make_request(), there should be no deadlock (of this sort).