On Mon, 5 Oct 2015, Mike Snitzer wrote: > Mikulas, > > Could it be that cond_resched() wasn't unplugging? As was > recently raised in this thread: https://lkml.org/lkml/2015/9/18/378 > Chris Mason's patch from that thread fixed this issue... I _think_ Linus > has since committed Chris' work but I haven't kept my finger on the > pulse of that issue. I think it doesn't matter (regarding correctness) if cond_reched unplugs on not. If it didn't unplug, the process will be scheduled later, and it will eventually reach the point where it unplugs. > FYI, I've put rebased versions of your 2 patches in my wip branch, see: > http://git.kernel.org/cgit/linux/kernel/git/snitzer/linux.git/log/?h=wip > > I tweaked the 2nd patch that adds bio_list to plug so that > generic_make_request's checks for in_generic_make_request isn't racey > (your original patch could happen to have current-plug set but > in_generic_make_request not yet set). I don't recommend that second patch (http://git.kernel.org/cgit/linux/kernel/git/snitzer/linux.git/commit/?h=wip&id=5e740c2e45a767d8d6ef8ca36b0db705ef6259c4). The patch just complicates things without adding any value. It's also not correct because it plugs bios at places when bios aren't supposed to be plugged > Anyway, I'm just dusting off your earlier work and seeing if I can make > sense of a way forward that meets Jens' approval. Jens, if adding a > bio_list to struct blk_plug isn't what you were after either please be > more specific on what you would like to see... > > Thanks, > Mike Mikulas -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
