On Mon, Jan 17, 2022 at 06:37:12PM +0300, Dmitry Osipenko wrote: > 17.01.2022 00:39, Michał Mirosław пишет: > > On Sun, Jan 16, 2022 at 09:34:42PM +0300, Dmitry Osipenko wrote: > >> 16.01.2022 21:03, Michał Mirosław пишет: > >>> On Sun, Jan 16, 2022 at 08:54:08PM +0300, Dmitry Osipenko wrote: > >>>> 16.01.2022 19:02, Michał Mirosław пишет: > >>>>> To patches that, combined, reduce I2C driver's code by ~2kB and a bit > >>>>> from runtime overhead for non-Tegra20 or non-Tegra210 builds. > >>>>> > >>>>> Michał Mirosław (2): > >>>>> i2c: tegra: allow DVC support to be compiled out > >>>>> i2c: tegra: allow VI support to be compiled out > >>>>> > >>>>> drivers/i2c/busses/Kconfig | 16 ++++++++++++++++ > >>>>> drivers/i2c/busses/i2c-tegra.c | 35 +++++++++++++++++++++------------- > >>>>> 2 files changed, 38 insertions(+), 13 deletions(-) > >>>>> > >>>> > >>>> 2KB is a too small difference to justify the ifdefs and Kconfig entries, > >>>> IMO. > >>> > >>> Maybe I should have mentioned that it's ~20%? With my "embedded" hat on: > >>> I think it might be small, but sometimes it is the difference between > >>> bootable kernel or one too big. > >> > >> 10KB is a small size too. I'm very doubtful that such changes make any > >> real difference in practice. > >> > >> Much more practical should be to modularize more kernel code. You should > >> be able to squeeze zImage down to 3MB without any code changes by > >> toggling more kernel config options to =m. Try to use grate_defconfig > >> [1] for the base, that is what postmarketOS kernel build uses. > > > > For normal system this solution is workable. But for recovery, where you > > have to fit kernel+initrd in whatever small partition is provided (like > > eg. in Transformers 8MiB), it becomes a problem from time to time. > > (In this case, modules make it worse due to additional overhead in > > kernel and userspace). > > My point is that 2KB very likely won't change anything for you. I'd > suggest to take a look at a more "fat" drivers, like DRM/host1x for > example. I suppose it should be possible to save at least couple > hundreds KB by trimming those fat drivers. No doubt we can find more code to trim. :-) This one was cheap and easy, though. BTW, I worked around host1x size by using simpledrmfb instead, so I'm not sure there will be much benefit to digging there. Best Regards Michał Mirosław
