Tomas Vondra <tomas.von...@enterprisedb.com> writes:
> I suspect it's a pre-existing bug in Slab allocator, because it does this:
> #define SlabBlockGetChunk(slab, block, idx) \
> ((MemoryChunk *) ((char *) (block) + sizeof(SlabBlock) \
> + (idx * slab->fullChunkSize)))
> and SlabBlock is only 20B, i.e. not a multiple of 8B. Which would mean
> that even if we allocate block and size the chunks carefully (with all
> the MAXALIGN things), we ultimately slice the block incorrectly.
Right, same conclusion I just came to. But it's not a "pre-existing"
bug, because sizeof(SlabBlock) *was* maxaligned until David added
another field to it.
I think adding a padding field to SlabBlock would be a less messy
solution than your patch.
regards, tom lane
