The patch titled
Subject: arm64/mm: __always_inline to improve fork() perf
has been added to the -mm mm-unstable branch. Its filename is
arm64-mm-__always_inline-to-improve-fork-perf.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/arm64-mm-__always_inline-to-improve-fork-perf.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Ryan Roberts <ryan.roberts@xxxxxxx>
Subject: arm64/mm: __always_inline to improve fork() perf
Date: Thu, 15 Feb 2024 10:32:04 +0000
As set_ptes() and wrprotect_ptes() become a bit more complex, the compiler
may choose not to inline them. But this is critical for fork()
performance. So mark the functions, along with contpte_try_unfold() which
is called by them, as __always_inline. This is worth ~1% on the fork()
microbenchmark with order-0 folios (the common case).
Link: https://lkml.kernel.org/r/20240215103205.2607016-18-ryan.roberts@xxxxxxx
Signed-off-by: Ryan Roberts <ryan.roberts@xxxxxxx>
Acked-by: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Alistair Popple <apopple@xxxxxxxxxx>
Cc: Andrey Ryabinin <ryabinin.a.a@xxxxxxxxx>
Cc: Ard Biesheuvel <ardb@xxxxxxxxxx>
Cc: Barry Song <21cnbao@xxxxxxxxx>
Cc: Borislav Petkov (AMD) <bp@xxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: James Morse <james.morse@xxxxxxx>
Cc: John Hubbard <jhubbard@xxxxxxxxxx>
Cc: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
Cc: Marc Zyngier <maz@xxxxxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Cc: Yang Shi <shy828301@xxxxxxxxx>
Cc: Zi Yan <ziy@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/arm64/include/asm/pgtable.h | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
--- a/arch/arm64/include/asm/pgtable.h~arm64-mm-__always_inline-to-improve-fork-perf
+++ a/arch/arm64/include/asm/pgtable.h
@@ -1206,8 +1206,8 @@ extern int contpte_ptep_set_access_flags
unsigned long addr, pte_t *ptep,
pte_t entry, int dirty);
-static inline void contpte_try_unfold(struct mm_struct *mm, unsigned long addr,
- pte_t *ptep, pte_t pte)
+static __always_inline void contpte_try_unfold(struct mm_struct *mm,
+ unsigned long addr, pte_t *ptep, pte_t pte)
{
if (unlikely(pte_valid_cont(pte)))
__contpte_try_unfold(mm, addr, ptep, pte);
@@ -1278,7 +1278,7 @@ static inline void set_pte(pte_t *ptep,
}
#define set_ptes set_ptes
-static inline void set_ptes(struct mm_struct *mm, unsigned long addr,
+static __always_inline void set_ptes(struct mm_struct *mm, unsigned long addr,
pte_t *ptep, pte_t pte, unsigned int nr)
{
pte = pte_mknoncont(pte);
@@ -1360,8 +1360,8 @@ static inline int ptep_clear_flush_young
}
#define wrprotect_ptes wrprotect_ptes
-static inline void wrprotect_ptes(struct mm_struct *mm, unsigned long addr,
- pte_t *ptep, unsigned int nr)
+static __always_inline void wrprotect_ptes(struct mm_struct *mm,
+ unsigned long addr, pte_t *ptep, unsigned int nr)
{
if (likely(nr == 1)) {
/*
_
Patches currently in -mm which might be from ryan.roberts@xxxxxxx are
tools-mm-add-thpmaps-script-to-dump-thp-usage-info.patch
arm64-mm-make-set_ptes-robust-when-oas-cross-48-bit-boundary.patch
mm-clarify-the-spec-for-set_ptes.patch
mm-thp-batch-collapse-pmd-with-set_ptes.patch
mm-introduce-pte_advance_pfn-and-use-for-pte_next_pfn.patch
arm64-mm-convert-pte_next_pfn-to-pte_advance_pfn.patch
x86-mm-convert-pte_next_pfn-to-pte_advance_pfn.patch
mm-tidy-up-pte_next_pfn-definition.patch
arm64-mm-convert-read_onceptep-to-ptep_getptep.patch
arm64-mm-convert-set_pte_at-to-set_ptes-1.patch
arm64-mm-convert-ptep_clear-to-ptep_get_and_clear.patch
arm64-mm-new-ptep-layer-to-manage-contig-bit.patch
arm64-mm-split-__flush_tlb_range-to-elide-trailing-dsb.patch
arm64-mm-wire-up-pte_cont-for-user-mappings.patch
arm64-mm-implement-new-wrprotect_ptes-batch-api.patch
arm64-mm-implement-new-clear_full_ptes-batch-apis.patch
mm-add-pte_batch_hint-to-reduce-scanning-in-folio_pte_batch.patch
arm64-mm-implement-pte_batch_hint.patch
arm64-mm-__always_inline-to-improve-fork-perf.patch
arm64-mm-automatically-fold-contpte-mappings.patch
