On Thu, Sep 12, 2013 at 02:19:13PM -0400, Steven Rostedt wrote: > > This is something that either Peter or Frederic need to look at.
I spent yesterday trying to bisect this, but kept running into other perf/ftrace traces, which makes it pretty much impossible. The current one I'm staring at is this from LIST_DEBUG.. list_del corruption. next->prev should be prev (ffff88000fb812b0), but was ffff88000fb812b0. (next=ffff88009df8b7b0). The sharp eyed will notice that those first two addresses are actually the same. So we matched the next->prev != prev test, but at the time we got to the printk that follows in the WARN, the inverse was true. Smells like a race of some kind. [ 2481.228418] Call Trace: [ 2481.232705] [<ffffffff8171f5dd>] dump_stack+0x54/0x74 [ 2481.237025] [<ffffffff810540bd>] warn_slowpath_common+0x7d/0xa0 [ 2481.241357] [<ffffffff8105412c>] warn_slowpath_fmt+0x4c/0x50 [ 2481.245637] [<ffffffff810540e5>] ? warn_slowpath_fmt+0x5/0x50 [ 2481.249890] [<ffffffff8132c222>] __list_del_entry+0x62/0xf0 [ 2481.254109] [<ffffffff81143a88>] list_del_event+0xc8/0xe0 [ 2481.258310] [<ffffffff81143b2b>] perf_remove_from_context+0x8b/0xf0 [ 2481.262497] [<ffffffff81145444>] perf_event_release_kernel+0x54/0x90 [ 2481.266688] [<ffffffff811464d3>] put_event+0x133/0x1c0 [ 2481.270866] [<ffffffff811463d0>] ? put_event+0x30/0x1c0 [ 2481.275066] [<ffffffff81146570>] perf_release+0x10/0x20 [ 2481.279277] [<ffffffff811bf2ca>] __fput+0xfa/0x2e0 [ 2481.283488] [<ffffffff811bf4fe>] ____fput+0xe/0x10 [ 2481.287713] [<ffffffff8107c11c>] task_work_run+0xac/0xe0 [ 2481.291958] [<ffffffff810559bc>] do_exit+0x2cc/0xcc0 [ 2481.296194] [<ffffffff81732880>] ? ftrace_call+0x5/0x2f [ 2481.300435] [<ffffffff810577cc>] do_group_exit+0x4c/0xc0 [ 2481.304654] [<ffffffff81057854>] SyS_exit_group+0x14/0x20 [ 2481.308857] [<ffffffff81732e54>] tracesys+0xdd/0xe2 [ 2481.313051] ---[ end trace fa3e551eb20e0c0f ]--- Dave -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/