Hmm That would trade off a stack pointer + a compare vs always doing the move.
Thats fine until I have to add the _mc() version, then the put back would be an atomic, and most of the time the return from this is probably not changed… I really would prefer not to since the compare and maybe store vs the always store.. though the same now, would be far more expensive in the _mc version.. if we do a _mc version of course ;-) But I am willing to do whatever .. since this really needs to be fixed. R On Feb 5, 2013, at 1:52 PM, John Baldwin wrote: > On Tuesday, February 05, 2013 12:44:01 pm Randall Stewart wrote: >> Actually, no it is used. >> >> If you look in if_var.h int he drbr_putback() function, it does >> a buf_ring_swap when the old mbuf pointer does not equal the >> new mbuf pointer. This *does* happen, I crashed at least once >> yesterday when the igb driver did something to free the original >> mbuf and return a new mbuf with the data (prepend or some such). >> >> I also have found several issues that I have fixed this morning.. its been >> crash city on my test beds.. >> >> Here is the latest patch with all fixes and suggested changes from emaste > (thanks Ed) > > Actually, one more suggestion then (since you have to keep putback). It > would be nice to not have to require 'snext' in all the callers. How > about replace buf_ring_swap() with a buf_ring_putback_sc() that accepts the > mbuf and just stores it at the head unconditionally and have drbr_putback() > use that? > > -- > John Baldwin > _______________________________________________ > freebsd-net@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-net > To unsubscribe, send any mail to "freebsd-net-unsubscr...@freebsd.org" > ------------------------------ Randall Stewart 803-317-4952 (cell) _______________________________________________ freebsd-net@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-net To unsubscribe, send any mail to "freebsd-net-unsubscr...@freebsd.org"
