hi Rob, Marek and Frank: > > > The __reserved_mem_init_node will call region specific reserved memory > > > init codes, but once all compatibled init codes failed, the memory region > > > will left in memory.reserved and cause leakage. > > > > > > Take cma reserve memory DTS for example, if user declare 1MB size, > > > which is not align to (PAGE_SIZE << max(MAX_ORDER - 1, > > > pageblock_order)), rmem_cma_setup will return -EINVAL. > > > Meanwhile, rmem_dma_setup will also return -EINVAL since "reusable" > > > property is not set. If finally there is no reserved memory init pick up > > > this memory, kernel will left the 1MB leak in memory.reserved. > > > > > > This patch will remove this kind of memory from memory.reserved, only > > > when __reserved_mem_init_node return neither 0 nor -ENOENT. > > > > I'm not sure that un-reserving memory on error is the correct > > behavior. It may be fine for something like CMA, but if it is some > > shared memory used by another processor in the system not reserving it > > would probably never be correct. > > In this patch, we un-reserving memory ONLY if explicit compatible matching fail. > That mean driver found something wrong while matching and let OS know. > (But reserved-memory without compatible property will not be affected.) > > So per ur explaination, there would be cases that driver reported > matching memory fail, > but the memory is still needed by another processor? Would you mind to give some comment and suggestion for this patch? Sincerely appreciate ur kind help.
