Hi, On Mon, Apr 15, 2019 at 10:05:18AM +0800, Chen Zhou wrote: > Hi Mike, > > On 2019/4/14 20:10, Mike Rapoport wrote: > >> > >> solution A: phys_addr_t start[INIT_MEMBLOCK_RESERVED_REGIONS * 2]; > >> phys_addr_t end[INIT_MEMBLOCK_RESERVED_REGIONS * 2]; > >> start, end is physical addr > >> > >> solution B: int start_rgn[INIT_MEMBLOCK_REGIONS], end_rgn[INIT_MEMBLOCK_REGIONS]; > >> start_rgn, end_rgn is rgn index > >> > >> Solution B do less remove operations and with no warning comparing to solution A. > >> I think solution B is better, could you give some suggestions? > > > > Solution B is indeed better that solution A, but I'm still worried by > > relatively large arrays on stack and the amount of loops :( > > > > The very least we could do is to call memblock_cap_memory_range() to drop > > the memory before and after the ranges we'd like to keep. > > 1. relatively large arrays > As my said above, the start_rgn, end_rgn is rgn index, we could use unsigned char type. Let's stick to int for now > 2. loops > Loops always exist, and the solution with fewer loops may be just encapsulated well. Of course the loops are there, I just hoped we could get rid of the nested loop and get away with single passes in all the cases. Apparently it's not the case :( > Thanks, > Chen Zhou > -- Sincerely yours, Mike.
