Re: mm: delay rmap removal until after TLB flush
From: Linus Torvalds
Date: Wed Nov 02 2022 - 13:55:32 EST
On Wed, Nov 2, 2022 at 2:15 AM Christian Borntraeger
<borntraeger@xxxxxxxxxxxxx> wrote:
>
> It certainly needs a build fix for s390:
>
> In file included from kernel/sched/core.c:78:
> ./arch/s390/include/asm/tlb.h: In function '__tlb_remove_page_size':
> ./arch/s390/include/asm/tlb.h:50:17: error: implicit declaration of function 'page_zap_pte_rmap' [-Werror=implicit-function-declaration]
> 50 | page_zap_pte_rmap(page);
> | ^~~~~~~~~~~~~~~~~
Hmm. I'm not sure if I can add a
#include <linux/rmap.h>
to that s390 asm header file without causing more issues.
The minimal damage would probably be to duplicate the declaration of
page_zap_pte_rmap() in the s390 asm/tlb.h header where it is used.
Not pretty to have two different declarations of that thing, but
anything that then includes both <asm/tlb.h> and <linux/rmap.h> (which
is much of mm) would then verify the consistency of them.
So I'll do that minimal fix and update that branch, but if s390 people
end up having a better fix, please holler.
Linus