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.
