Hi Peter, On Mon, 2018-07-09 at 17:53 +0300, Alexey Brodkin wrote: > 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? Ping! Should I send v4 with ARCH_KMALLOC_MINALIGN used for alignment if explicitly set __aligned__(8) will break x86_32? -Alexey
