Bug 796401 – sys-kernel/gentoo-sources-5.12.11 won't compile with alternative CPU scheduler (error: implicit declaration of function ‘sched_feat’)

• Status: RESOLVED FIXED
• Product: Gentoo Linux

[Description Marek Bartosiewicz 2021-06-17 05:19:52 UTC]

I use BMQ and I copied my (working) .config from gentoo-sources-5.12.10. Compilation fails:

In file included from kernel/sched/alt_core.c:46:
kernel/sched/pelt.h: In function ‘cfs_se_util_change’:
kernel/sched/pelt.h:51:7: error: implicit declaration of function ‘sched_feat’; did you mean ‘sched_dead’? [-Werror=implicit-function-declaration]
   51 |  if (!sched_feat(UTIL_EST))
      |       ^~~~~~~~~~
      |       sched_dead
kernel/sched/pelt.h:51:18: error: ‘UTIL_EST’ undeclared (first use in this function)
   51 |  if (!sched_feat(UTIL_EST))
      |                  ^~~~~~~~
kernel/sched/pelt.h:51:18: note: each undeclared identifier is reported only once for each function it appears in

[Comment 1 Amit Prakash Ambasta 2021-06-17 10:46:46 UTC]

Can confirm this issue as well.

[Comment 2 setun.90 2021-06-17 11:05:35 UTC]

Happened to me here too. I `find`ed and grepped on my own initiative out of curiosity; sched_feat is a macro defined in kernel/sched/sched.h, which should be included before pelt.h wherever the latter is included. So why would GCC be treating it as a function?

[Comment 3 Mike Pagano 2021-06-17 11:13:26 UTC]

Created attachment 716589 [details, diff]
[PATCH] prjc: fix compilation error

You can use this patch, if it doesn't make it in BMQ before 5.12.12 is released, I'll incorporate it into genpatches

[Comment 4 Ionen Wolkens 2021-06-17 14:18:56 UTC]

*** Bug 796479 has been marked as a duplicate of this bug. ***

[Comment 5 Marek Bartosiewicz 2021-06-17 18:15:34 UTC]

Thanks, patch works.

[Comment 6 Mike Pagano 2021-06-18 13:46:33 UTC]

This is release in gentoo-sources-5.12.12

Thanks for reporting.