On Sat, Sep 05, 2015 at 04:48:40PM +0100, Richard W.M. Jones wrote: > On Sat, Sep 05, 2015 at 04:34:39PM +0100, Richard W.M. Jones wrote: > > [ 52.259269] BUG: unable to handle kernel NULL pointer dereference at 00000000000009c8 > > [ 52.259269] IP: [<ffffffff813f8b10>] __blkg_lookup+0x40/0xe0 > > And also: > > $ addr2line -e /usr/lib/debug/lib/modules/4.3.0-0.rc0.git7.1.rwmj3.fc24.x86_64/vmlinux ffffffff813f8b10 > /usr/src/debug/kernel-4.2.fc24/linux-4.3.0-0.rc0.git7.1.rwmj3.fc24.x86_64/block/blk-cgroup.c:158 > > 152 /* > 153 * Hint didn't match. Look up from the radix tree. Note that the > 154 * hint can only be updated under queue_lock as otherwise @blkg > 155 * could have already been removed from blkg_tree. The caller is > 156 * responsible for grabbing queue_lock if @update_hint. > 157 */ > 158 blkg = radix_tree_lookup(&blkcg->blkg_tree, q->id); Okay, found the bug. It was an existing problem which got exposed by the recent bypass change. Will soon post a patch. Thanks a lot! -- tejun -- To unsubscribe from this list: send the line "unsubscribe cgroups" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
