On Thu, Mar 21, 2013 at 05:12:01PM -0400, Alan Stern wrote: > On Thu, 21 Mar 2013, Alan Stern wrote: > > > On Thu, 21 Mar 2013, Soeren Moch wrote: > > > > > Now I found out what is going on here: > > > > > > In itd_urb_transaction() we allocate 9 iTDs for each URB with > > > number_of_packets == 64 in my case. The iTDs are added to > > > sched->td_list. For a frame-aligned scheduling we need 8 iTDs, the 9th > > > one is released back to the front of the streams free_list in > > > iso_sched_free(). This iTD was cleared after allocation and has a frame > > > number of 0 now. So for each allocation when now_frame == 0 we allocate > > > from the dma_pool, not from the free_list. > > > > Okay, that is a problem. But it shouldn't be such a big problem, > > because now_frame should not be equal to 0 very often. > > Oh, wait, now I get it. We never reach a steady state, because the > free list never shrinks, but occasionally it does increase when > now_frame is equal to 0. Even though that doesn't happen very often, > the effects add up. > > Very good; tomorrow I will send your patch in. Hi Alan, Soeren Could you word the description a bit better. If Alan did not get it without a bit of thought, few others are going to understand it without a better explanation. Thanks Andrew -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>