Messages in this thread Patch in this message | | | Date | Fri, 26 Jun 2009 08:16:18 +0300 (EEST) | From | Pekka J Enberg <> | Subject | Re: upcoming kerneloops.org item: get_page_from_freelist |
| |
Hi Ted,
On Thu, Jun 25, 2009 at 05:11:25PM -0500, Eric Sandeen wrote: > > ecryptfs used to do kmalloc(PAGE_CACHE_SIZE) & virt_to_page on that, and > > with SLUB + slub debug, that gave back non-aligned memory, causing > > eventual corruption ...
On Thu, 25 Jun 2009, Theodore Tso wrote: > Grumble. Any chance we could add an kmem_cache option which requires > the memory to be aligned? Otherwise we could rewrite our own sub-page > allocator in ext4 that only handled aligned filesystem block sizes > (i.e., 1k, 2k, 4k, etc.) but that would be really silly and be extra > code that really should be done once at core functionality.
We alredy have SLAB_HW_ALIGN but I wonder if this is a plain old bug in SLUB. Christoph, Nick, don't we need something like this in the allocator? Eric, does this fix your case?
Pekka
diff --git a/mm/slub.c b/mm/slub.c index 819f056..7cd1e69 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -2400,7 +2400,7 @@ static int calculate_sizes(struct kmem_cache *s, int forced_order) * user specified and the dynamic determination of cache line size * on bootup. */ - align = calculate_alignment(flags, align, s->objsize); + align = calculate_alignment(flags, align, size); /* * SLUB stores one object immediately after another beginning from
| |