Comment 6 for bug 1866149

Revision history for this message
Thadeu Lima de Souza Cascardo (cascardo) wrote :

There is no other effect of disabling CONFIG_BASE_FULL save for changing CONFIG_BASE_SMALL.

CONFIG_BASE_SMALL won't have much effect save for other memory savings that really would be able to reduce some runtime performance. As for boot time, changing this setting should not be expected to cause any significant changes.

At focal, we have:

arch/x86/include/asm/mpspec.h: changes MAX_MP_BUSSES only on 32-bit systems.
drivers/tty/vt/vc_screen.c: change is not effective on memory reducing as of commit fcdba07ee390d
include/linux/udp.h:
include/linux/xarray.h:
kernel/futex.c:
kernel/user.c:
These are all reducing the initial size of hash structures, causing more list traversals to happen when there are hash collisions. From here, there would be some negative effect on runtime execution, but memory allocation of these hashes should not introduce significant boot time regression as I mentioned.

So, all in all, there is really no reason to keep CONFIG_BASE_SMALL=1 in any of the kernels we ship.