回复: [PATCH] lockdep: Fix upper limit for LOCKDEP_BITS configs

[zhangxiaomeng (A)]

Thank you for the response. I should clarify that the issue occurs when modifying additional config values. Specifically, when LOCKDEP_BITS is set to 24 along with setting LOCKDEP_CHAINS_BITS and LOCKDEP_STACK_TRACE_BITS to their maximum upper limits, the build fails.

Here are the exact steps to reproduce:

Run make menuconfig
Enable CONFIG_PROVE_LOCKING
Set the following values:
LOCKDEP_CHAINS_BITS = 21
LOCKDEP_BITS = 24
LOCKDEP_STACK_TRACE_BITS = 26
Build kernel 6.6 with make -j122

-----邮件原件-----
发件人: Carlos Llamas <cmllamas@xxxxxxxxxx> 
发送时间: 2025年3月15日 2:33
收件人: zhangxiaomeng (A) <zhangxiaomeng13@xxxxxxxxxx>
抄送: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>; linux-kernel@xxxxxxxxxxxxxxx; Boqun Feng <boqun.feng@xxxxxxxxx>; J. R. Okajima <hooanon05g@xxxxxxxxx>; Peter Zijlstra <peterz@xxxxxxxxxxxxx>; Waiman Long <longman@xxxxxxxxxx>; Ingo Molnar <mingo@xxxxxxxxxx>; Will Deacon <will@xxxxxxxxxx>
主题: Re: [PATCH] lockdep: Fix upper limit for LOCKDEP_BITS configs

On Fri, Mar 14, 2025 at 06:47:29AM +0000, Xiaomeng Zhang wrote:
> The upper limit that was initially setup for LOCKDEP_BITS configs is 
> too high (24 bit shift), which causes the kernel image size to exceed 
> KERNEL_IMAGE_SIZE (1024MB) limit. When LOCKDEP_BITS is set to 24, the 
> kernel image size grows to 1562.19MB.

This is not entirely accurate. Look at _how_ the new upper limits where determined in commit e638072e6172. This should build just fine:

	$ make defconfig
	$ ./scripts/config -e PROVE_LOCKING --set-val LOCKDEP_BITS 24
	$ make -s olddefconfig all

Is it not the case for you? My guess is that you've also changed _other_ configs and combined with that you hit the limit. If not, can you please provide the steps and commit you are using?

Thanks,
--
Carlos Llamas