Hi Peter, On Mon, 2018-07-09 at 16:49 +0200, Peter Zijlstra wrote: > On Mon, Jul 09, 2018 at 02:33:26PM +0000, Alexey Brodkin wrote: > > > In fact, since alloc_dr() uses kmalloc() to allocate the entire thing, > > > it is impossible to guarantee a larger alignment than kmalloc does. > > > > Well but 4-bytes [which is critical for atomic64_t] should be much less > > than a sane cache line length so above should work. > > AFAICT ARCH_KMALLOC_MINALIGN ends up being 4 on x86_32 (it doesn't > define ARCH_DMA_MINALIGN and doesn't seem to otherwise override the > thing). > > So unconditionally setting the alignment of devres::data to 8 seems > broken. Well but then what other options do we have to fix a problem with misaligned access to atomic64_t in drm_gpu_scheduler? -Alexey
