Where is PageHead defined in v5.0?

[Valdis Kl=?utf-8?Q?=c4=93?=tnieks]

On Wed, 27 Mar 2019 17:23:05 -0700, Igor Pylypiv said:
> and TESTPAGEFLAG defines PageHead:
>         #define TESTPAGEFLAG(uname, lname, policy) \
>         static __always_inline int Page##uname(struct page *page)
>         (https://elixir.bootlin.com/linux/v5.0.5/source/include/linux/page-flags.h#L215)

General tip:  If you're trying to find where the kernel defines FooBar,
and 'git grep FooBar' only finds uses and no definitions, it probably
means somebody got over-exuberant with the ## pre-processor
operator

'git grep Foo##' usually reveals the culprit. ;)