On Sun, May 09, 2004 at 10:56:37PM +0900, Atsushi Nemoto wrote: > ralf> We got tripped by a change in 2.6.6-rc2. Before that change the > ralf> kmalloc slab caches were being created with SLAB_HWCACHE_ALIGN > ralf> which results in L1_CACHE_SHIFT alignment for allocations of > ralf> L1_CACHE_SHIFT for slab caches that are at least that size. For > ralf> the sake of S390 this behaviour was changed; new it defaults to > ralf> BYTES_PER_WORD alignment which is four bytes. > > ralf> Fixed by defining ARCH_KMALLOC_MINALIGN as 8. > > Hmm, many drivers use kmalloc and pci_map_single for DMA buffer. So > ARCH_KMALLOC_MINALIGN should be L1_CACHE_BYTES for non-coherent > system? No, those drivers are simply broken. dma_get_cache_alignment() gives the mimimum alignment and width for DMA mappings and that value is larger than kmalloc alignment in almost all cases. Ralf
