On Thu, Sep 06, 2012 at 10:22:19AM +0300, Pekka Enberg wrote: > On Wed, Sep 5, 2012 at 1:02 AM, Pekka Enberg <[email protected]> wrote: > > > How significant is the speed gain? The "isa_done" flag makes code flow > > > more difficult to follow. > > On Wed, 5 Sep 2012, Yinghai Lu wrote: > > Not really much. > > > > when booting system: > > memmap=16m$128m memmap=16m$512m memmap=16m$256m memmap=16m$768m > > memmap=16m$1024m > > > > with the patch > > [ 0.000000] init_memory_mapping: [mem 0x00000000-0x07ffffff] > > [ 0.000000] [mem 0x00000000-0x07ffffff] page 2M > > [ 0.000000] init_memory_mapping: [mem 0x09000000-0x0fffffff] > > [ 0.000000] [mem 0x09000000-0x0fffffff] page 2M > > [ 0.000000] init_memory_mapping: [mem 0x11000000-0x1fffffff] > > [ 0.000000] [mem 0x11000000-0x1fffffff] page 2M > > [ 0.000000] init_memory_mapping: [mem 0x21000000-0x2fffffff] > > [ 0.000000] [mem 0x21000000-0x2fffffff] page 2M > > [ 0.000000] init_memory_mapping: [mem 0x31000000-0x3fffffff] > > [ 0.000000] [mem 0x31000000-0x3fffffff] page 2M > > [ 0.000000] init_memory_mapping: [mem 0x41000000-0x7fffdfff] > > [ 0.000000] [mem 0x41000000-0x7fdfffff] page 2M > > [ 0.000000] [mem 0x7fe00000-0x7fffdfff] page 4k > > > > otherwise will have > > > > [ 0.000000] init_memory_mapping: [mem 0x00000000-0x000fffff] > > [ 0.000000] [mem 0x00000000-0x000fffff] page 4k > > [ 0.000000] init_memory_mapping: [mem 0x00100000-0x07ffffff] > > [ 0.000000] [mem 0x00100000-0x001fffff] page 4k > > [ 0.000000] [mem 0x00200000-0x07ffffff] page 2M > > [ 0.000000] init_memory_mapping: [mem 0x09000000-0x0fffffff] > > [ 0.000000] [mem 0x09000000-0x0fffffff] page 2M > > [ 0.000000] init_memory_mapping: [mem 0x11000000-0x1fffffff] > > [ 0.000000] [mem 0x11000000-0x1fffffff] page 2M > > [ 0.000000] init_memory_mapping: [mem 0x21000000-0x2fffffff] > > [ 0.000000] [mem 0x21000000-0x2fffffff] page 2M > > [ 0.000000] init_memory_mapping: [mem 0x31000000-0x3fffffff] > > [ 0.000000] [mem 0x31000000-0x3fffffff] page 2M > > [ 0.000000] init_memory_mapping: [mem 0x41000000-0x7fffdfff] > > [ 0.000000] [mem 0x41000000-0x7fdfffff] page 2M > > [ 0.000000] [mem 0x7fe00000-0x7fffdfff] page 4k > > OK. Is there any other reason than performance to do this?
May be minor, but .. The first range [mem 0x00000000-0x07ffffff] is covered entirely by 2M page tables, instead of some 4K + some 2M. -Jacob > > Pekka > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
