Re: mainline build failure due to e240e53ae0ab ("mm, slub: add CONFIG_SLUB_TINY")

[Guenter Roeck]

On Tue, Dec 13, 2022 at 10:26:20AM +0000, Sudip Mukherjee (Codethink) wrote:
> Hi All,
> 
> The latest mainline kernel branch fails to build xtensa allmodconfig 
> with gcc-11 with the error:
> 
> kernel/kcsan/kcsan_test.c: In function '__report_matches':
> kernel/kcsan/kcsan_test.c:257:1: error: the frame size of 1680 bytes is larger than 1536 bytes [-Werror=frame-larger-than=]
>   257 | }
>       | ^
> 
> git bisect pointed to e240e53ae0ab ("mm, slub: add CONFIG_SLUB_TINY")
> 

In part that is because above commit changes Kconfig dependencies such
that xtensa:allmodconfig actually tries to build kernel/kcsan/kcsan_test.o.
In v6.1, CONFIG_KCSAN_KUNIT_TEST is not enabled for xtensa:allmodconfig.

Downside of the way SLUB_TINY is defined is that it is enabled for all
allmodconfig / allyesconfig builds, which then disables building a lot
of the more sophisticated memory allocation options.

Guenter