On Tue, Apr 19, 2011 at 23:29, James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx> wrote: > Slub makes assumptions about page_to_nid() which are violated by > DISCONTIGMEM and !NUMA. ÂThis violation results in a panic because > page_to_nid() can be non-zero for pages in the discontiguous ranges and > this leads to a null return by get_node(). ÂThe assertion by the > maintainer is that DISCONTIGMEM should only be allowed when NUMA is also > defined. ÂHowever, at least six architectures: alpha, ia64, m32r, m68k, > mips, parisc violate this. ÂThe panic is a regression against slab, so > just mark slub broken in the problem configuration to prevent users > reporting these panics. How does the problem manifest itself? We're having a problem on m68k, which seems to go away when switching from SLUB to SLAB, or when reverting a commit in [2] (probably this was never reported upstream). References: [1] http://www.mail-archive.com/linux-m68k@xxxxxxxxxxxxxxx/msg02812.html [2] http://www.spinics.net/lists/linux-m68k/msg03401.html > Cc: stable@xxxxxxxxxx > Signed-off-by: James Bottomley <James.Bottomley@xxxxxxx> > > --- > > diff --git a/init/Kconfig b/init/Kconfig > index 56240e7..a7ad8fb 100644 > --- a/init/Kconfig > +++ b/init/Kconfig > @@ -1226,6 +1226,7 @@ config SLAB > Â Â Â Â Âper cpu and per node queues. > > Âconfig SLUB > + Â Â Â depends on BROKEN || NUMA || !DISCONTIGMEM > Â Â Â Âbool "SLUB (Unqueued Allocator)" > Â Â Â Âhelp > Â Â Â Â Â SLUB is a slab allocator that minimizes cache line usage Gr{oetje,eeting}s, Â Â Â Â Â Â Â Â Â Â Â Â Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. Â Â Â Â Â Â Â Â Â Â Â Â Â ÂÂ ÂÂ -- Linus Torvalds -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
