On Mon 23-04-18 20:06:16, Mikulas Patocka wrote: [...] > @@ -404,6 +405,12 @@ void *kvmalloc_node(size_t size, gfp_t f > */ > WARN_ON_ONCE((flags & GFP_KERNEL) != GFP_KERNEL); > > +#ifdef CONFIG_DEBUG_SG > + /* Catch bugs when the caller uses DMA API on the result of kvmalloc. */ > + if (!(prandom_u32_max(2) & 1)) > + goto do_vmalloc; > +#endif
I really do not think there is anything DEBUG_SG specific here. Why you simply do not follow should_failslab path or even reuse the function? > + > /* > * We want to attempt a large physically contiguous block first because > * it is less likely to fragment multiple larger blocks and therefore > @@ -427,6 +434,9 @@ void *kvmalloc_node(size_t size, gfp_t f > if (ret || size <= PAGE_SIZE) > return ret; > > +#ifdef CONFIG_DEBUG_SG > +do_vmalloc: > +#endif > return __vmalloc_node_flags_caller(size, node, flags, > __builtin_return_address(0)); > } -- Michal Hocko SUSE Labs
