On Sat, Oct 31, 2015 at 12:34 PM, Al Viro <viro@xxxxxxxxxxxxxxxxxx> wrote: > > ... and here's the current variant of mine. Ugh. I really liked how simple mine ended up being. Yours is definitely not. And based on the profiles from Eric, finding the fd is no longer the problem even with my simpler patch. The problem ends up being the contention on the file_lock spinlock. Eric, I assume that's not "expand_fdtable", since your test-program seems to expand the fd array at the beginning. So it's presumably all from the __alloc_fd() use, but we should double-check.. Eric, can you do a callgraph profile and see which caller is the hottest? Linus -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html