Messages in this thread | | | Date | Wed, 31 Oct 2012 09:59:40 +0200 | Subject | Re: [PATCH] slab : allow SLAB_RED_ZONE and SLAB_STORE_USER to work on arm | From | Pekka Enberg <> |
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Hi,
(Adding more people to CC.)
On Tue, Oct 16, 2012 at 2:17 PM, Matthieu CASTET <matthieu.castet@parrot.com> wrote: > From: Matthieu CASTET <castet.matthieu@free.fr> > > on cortexA8 (omap3) ralign is 64 and __alignof__(unsigned long long) is 8. > So we always disable debug. > > This patch is based on 5c5e3b33b7cb959a401f823707bee006caadd76e, but fix > case were align < sizeof(unsigned long long). > > Signed-off-by: Matthieu Castet <matthieu.castet@parrot.com> > CC: Russell King <rmk@arm.linux.org.uk> > CC: Pekka Enberg <penberg@cs.helsinki.fi> > --- > mm/slab.c | 8 +++----- > 1 file changed, 3 insertions(+), 5 deletions(-) > > diff --git a/mm/slab.c b/mm/slab.c > index c685475..8427901 100644 > --- a/mm/slab.c > +++ b/mm/slab.c > @@ -2462,9 +2462,6 @@ __kmem_cache_create (const char *name, size_t size, size_t align, > if (ralign < align) { > ralign = align; > } > - /* disable debug if necessary */ > - if (ralign > __alignof__(unsigned long long)) > - flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER); > /* > * 4) Store it. > */ > @@ -2491,8 +2488,9 @@ __kmem_cache_create (const char *name, size_t size, size_t align, > */ > if (flags & SLAB_RED_ZONE) { > /* add space for red zone words */ > - cachep->obj_offset += sizeof(unsigned long long); > - size += 2 * sizeof(unsigned long long); > + int offset = max(align, sizeof(unsigned long long)); > + cachep->obj_offset += offset; > + size += offset + sizeof(unsigned long long); > } > if (flags & SLAB_STORE_USER) { > /* user store requires one word storage behind the end of
This piece of code tends to break in peculiar ways every time someone touches it. I could use some more convincing in the changelog this time it won't...
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