On Wed, 6 Nov 2013, Andreas Herrmann wrote: > When I've used slub_debug kernel option (e.g. > "slub_debug=,skbuff_fclone_cache" or similar) on a debug session I've > seen a panic like: Hmmm.. That looks like its due to some slabs not having names during early boot. kmem_cache_flags is called with NULL as a parameter. Are you sure that this fixes the issue? Looks like the kmem_cache_flag function should fail regardless of how early you set it. AFAICT the right fix would be: Subject: slub: Handle NULL parameter in kmem_cache_flags kmem_cache_flags may be called with NULL parameter during early boot. Skip the test in that case. Signed-off-by: Christoph Lameter <cl@xxxxxxxxx> Index: linux/mm/slub.c =================================================================== --- linux.orig/mm/slub.c 2013-10-15 13:55:44.000000000 -0500 +++ linux/mm/slub.c 2013-11-06 13:09:21.810583134 -0600 @@ -1217,7 +1217,7 @@ static unsigned long kmem_cache_flags(un /* * Enable debugging if selected on the kernel commandline. */ - if (slub_debug && (!slub_debug_slabs || + if (slub_debug && name && (!slub_debug_slabs || !strncmp(slub_debug_slabs, name, strlen(slub_debug_slabs)))) flags |= slub_debug; -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>