On Mon, 2016-08-22 at 09:46 -0700, Luck, Tony wrote: > On Sun, Aug 21, 2016 at 05:02:41PM -0700, Joe Perches wrote: > > Marking arrays as const makes for smaller data. > Joe,
Hi Tony > "a few hundred" seems to be exaggeration. > > Before: > $ size drivers/edac/skx_edac.ko > text data bss dec hex filename > 8435 1024 24 9483 250b drivers/edac/skx_edac.ko > > After: > $ size drivers/edac/skx_edac.ko > text data bss dec hex filename > 8531 944 24 9499 251b drivers/edac/skx_edac.ko > > so "data" was reduced by 80 bytes, but "text" went up by 96. Yeah, it was a few hundred in an allyesconfig and I neglected to test the defconfig. $ size drivers/edac/skx_edac.o* (x86-64) text data bss dec hex filename 6677 64 24 6765 1a6d drivers/edac/skx_edac.o.defconfig.new 6546 176 24 6746 1a5a drivers/edac/skx_edac.o.defconfig.old 20609 5744 320 26673 6831 drivers/edac/skx_edac.o.new 20273 6064 320 26657 6821 drivers/edac/skx_edac.o.old > Net increase of 16 (perhaps because some padding for alignment???) > > Making read-only data const is a good idea in general, but > do we want to do it if it *increases* kernel footprint? Marking all data const that can be const is a good thing. It reduces exposure and eliminates unintentional overwriting.
