Compile time error while building Linux Kernel 4.18

proy_ · 10-24-2018, 02:38 PM

I am trying to disable inlining while compiling Linux kernel 4.18.

For this I have updated the Makefile according to: https://elinux.org/Kernel_dynamic_me...against_gcc.29

But while compiling I am getting following error:

>error: call to ‘__compiletime_assert_1094’ declared with attribute error: BUILD_BUG_ON failed: p4d_large(*p4d)

How can I get rid of the error while disabling inlining during kernel build?

business_kid · 10-25-2018, 06:23 AM

Divide and conquer.

Does it make without those CFLAGS? If so, enable them one at a time. I would say I have always found the kernel diagnostic enough on it's own. I would also read up on inlining. This seems to have interesting links. https://www.kernel.org/doc/local/inline.html

Why are you worried about inlining? AFAICT, gcc is continually a WIP in this area (I gather), and nobody really knows what order the cpu executes improvements anyhow, CPU microcode has been revised many times, so if your elinux docs aren't very up to date I wouldn't trust them.

proy_ · 10-25-2018, 06:36 AM

Thanks for the advice. I will try enabling them one at a time.

I want to disable inlining to get the accurate calling context. I am trying to understand some memory issues which can be understood through accurate call context. The observed call context is pointing to last known non-inlined function hiding all the inlined function calls which is not enough for my analysis. In fact, this is the reason for elinux is disabling inlining in https://elinux.org/Kernel_dynamic_me...against_gcc.29

business_kid · 10-25-2018, 12:01 PM

Hey - that kernel Makefile patch dates from August 2012!

IIRC we were on gcc-4.x. I'm now running gcc-8.2.0. Every major version release is a compatibility break in some area. We've had 4 of them, standards have changed and to make a long story short, I would not take that url too seriously. Get something current.