Messages in this thread | | | Date | Fri, 1 Jun 2007 16:57:20 -0700 (PDT) | From | Linus Torvalds <> | Subject | Re: [RFC] [PATCH] cpuset operations causes Badness at mm/slab.c:777 warning |
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On Fri, 1 Jun 2007, Christoph Lameter wrote: > > A too large alloc is >32MB or MAX_ORDER << PAGE_SIZE. A BUG_ON in > kmalloc_slab() will trigger.
Did we use to BUG_ON()? I think that's wrong. There are ways for users to potentially ask the kernel to do big allocations, and the correct response is to say "no can do", not to crash!
> Here is the updated patch. It works fine here: > > SLUB: Return BADPTR instead of warning for kmalloc(0)
Looks fine to me. My only comment is that
> - if (!x) > + if (!x || x == BADPTR) > return;
This could be micro-optimized (again, non-standard, but it should be "practically portable") to have just a single test using something like
if ((unsigned long)x <= 16) return;
but I guess it doesn't really matter much.
I think this is better than what we have now, but I also suspect it's *not* something we should try this late in the -rc sequence ;)
Andrew, want to take this patch to -mm to see if it triggers anything?
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