Re: [PATCH V13 4/4] LoongArch: Enable ARCH_WANT_HUGETLB_PAGE_OPTIMIZE_VMEMMAP
From: Philippe Mathieu-Daudé
Date: Wed Oct 26 2022 - 09:44:47 EST
On 26/10/22 14:59, Huacai Chen wrote:
On Mon, Oct 24, 2022 at 4:04 PM Guo Ren <guoren@xxxxxxxxxx> wrote:
On Mon, Oct 24, 2022 at 3:05 PM Huacai Chen <chenhuacai@xxxxxxxxxxx> wrote:
From: Feiyang Chen <chenfeiyang@xxxxxxxxxxx>
The feature of minimizing overhead of struct page associated with each
HugeTLB page is implemented on x86_64. However, the infrastructure of
this feature is already there, so just select ARCH_WANT_HUGETLB_PAGE_
OPTIMIZE_VMEMMAP is enough to enable this feature for LoongArch.
To avoid the following build error on LoongArch we should include linux/
static_key.h in page-flags.h. This is straightforward but the build
error is implicitly a LoongArch-specific problem, because ARM64 and X86
have already include static_key.h from their arch-specific core headers.
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index 0b0ae5084e60..1aafdc73e399 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -9,6 +9,7 @@
#include <linux/types.h>
#include <linux/bug.h>
#include <linux/mmdebug.h>
+#include <linux/static_key.h>
Em... riscv needn't this.
Would guarding the header suffice and make riscv OK with this patch?
#ifdef CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP
#include <linux/static_key.h>
#endif
I found that after 36d4b36b69590fed99356a4426c940a25 (" lib/nodemask:
inline next_node_in() and node_random()"), build errors have gone. But
I think this is just an accident. Because that commit adds random.h
inclusion in nodemask.h, then asm-offsets.c --> sched.h --> nodemask.h
--> random.h --> once.h --> jump_label.h. If one day this chain is
adjusted, then build errors come again.
On the other hand, page-flags.h is obviously using some static_key
macros, including static_key.h is straightforward for building.
Huacai