Re: [PATCH] selftests/mm: fix khugepaged_race build with older glibc

[Kiryl Shutsemau]

On Tue, Oct 27, 2026 at 08:20:13PM +0800, Zenghui Yu wrote:
> From: "Zenghui Yu (Huawei)" <zenghui.yu@xxxxxxxxx>
> 
> glibc versions before 2.37 do not define MADV_COLLAPSE in <sys/mman.h>, so
> khugepaged_race fails to build against them (e.g. glibc 2.34):
> 
> [root@localhost mm]# make
>   CC       khugepaged_race
> khugepaged_race.c: In function 'main':
> khugepaged_race.c:506:23: error: 'MADV_COLLAPSE' undeclared (first use in this function); did you mean 'MADV_COLD'?
>   506 |       hpage_pmd_size, MADV_COLLAPSE);
>       |                       ^~~~~~~~~~~~~
>       |                       MADV_COLD
> khugepaged_race.c:506:23: note: each undeclared identifier is reported only once for each function it appears in
> make: *** [../lib.mk:225: /data/code/mm/tools/testing/selftests/mm/khugepaged_race] Error 1
> 
> Include <linux/mman.h> to get the UAPI definition of MADV_COLLAPSE.
> 
> Fixes: 66c374464438 ("selftests/mm: add khugepaged race harness")
> Signed-off-by: Zenghui Yu (Huawei) <zenghui.yu@xxxxxxxxx>

Reviewed-by: Kiryl Shutsemau (Meta) <kas@xxxxxxxxxx>


-- 
  Kiryl Shutsemau / Kirill A. Shutemov