Max Kanushin <[email protected]> writes: > Thank you very much for the reply. My general idea is take control of all > request queues to block and unblock them manually depending on their load. > One of my steps is to find a length of a queue to decide if to block it. > Actually I think I've found the way. If I got it right, I can move from one > request to another within the list: > struct list_head queue_head; > So that I can calculate how many requests are there in the queue.
Hi, Max, The queue_head is the dispatch list for I/O, so it does not represent all I/O queued for a request_queue. The number of requests in the scheduler would be reflected by q->nr_sorted. The number of dispatched requests is in an array, in_flight. Cheers, Jeff > > Best regards, > Max Kanushin. > On Apr 29, 2016 6:32 PM, "Jeff Moyer" <[email protected]> wrote: > >> Max Kanushin <[email protected]> writes: >> >> > Hello, >> > >> > I was searching for a way to find out the length of a request_queue >> > (that is defined as a structure in >> > linux/include/linux/blkdev.h). However I am new to the kernel >> > development and can't figure out where is the actual list of requests >> > to be processed by an elevator. >> > Is there a way to iterate requests in a queue or at least find a >> > number of them? >> >> Hi, Max, >> >> What exactly are you trying to accomplish? >> >> Cheers, >> Jeff >>
