The patch titled
Subject: mm/mremap: allow arch runtime override
has been added to the -mm tree. Its filename is
mm-mremap-allow-arch-runtime-override.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-mremap-allow-arch-runtime-override.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-mremap-allow-arch-runtime-override.patch
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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxx>
Subject: mm/mremap: allow arch runtime override
Patch series "Speedup mremap on ppc64", v8.
This patchset enables MOVE_PMD/MOVE_PUD support on power. This requires
the platform to support updating higher-level page tables without
updating page table entries. This also needs to invalidate the Page Walk
Cache on architecture supporting the same.
This patch (of 3):
Architectures like ppc64 support faster mremap only with radix
translation. Hence allow a runtime check w.r.t support for fast mremap.
Link: https://lkml.kernel.org/r/20210616045735.374532-1-aneesh.kumar@xxxxxxxxxxxxx
Link: https://lkml.kernel.org/r/20210616045735.374532-2-aneesh.kumar@xxxxxxxxxxxxx
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Kalesh Singh <kaleshsingh@xxxxxxxxxx>
Cc: Nicholas Piggin <npiggin@xxxxxxxxx>
Cc: Joel Fernandes <joel@xxxxxxxxxxxxxxxxx>
Cc: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
Cc: Kirill A. Shutemov <kirill@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/powerpc/include/asm/tlb.h | 6 ++++++
mm/mremap.c | 15 ++++++++++++++-
2 files changed, 20 insertions(+), 1 deletion(-)
--- a/arch/powerpc/include/asm/tlb.h~mm-mremap-allow-arch-runtime-override
+++ a/arch/powerpc/include/asm/tlb.h
@@ -83,5 +83,11 @@ static inline int mm_is_thread_local(str
}
#endif
+#define arch_supports_page_table_move arch_supports_page_table_move
+static inline bool arch_supports_page_table_move(void)
+{
+ return radix_enabled();
+}
+
#endif /* __KERNEL__ */
#endif /* __ASM_POWERPC_TLB_H */
--- a/mm/mremap.c~mm-mremap-allow-arch-runtime-override
+++ a/mm/mremap.c
@@ -25,7 +25,7 @@
#include <linux/userfaultfd_k.h>
#include <asm/cacheflush.h>
-#include <asm/tlbflush.h>
+#include <asm/tlb.h>
#include "internal.h"
@@ -209,6 +209,15 @@ static void move_ptes(struct vm_area_str
drop_rmap_locks(vma);
}
+#ifndef arch_supports_page_table_move
+#define arch_supports_page_table_move arch_supports_page_table_move
+static inline bool arch_supports_page_table_move(void)
+{
+ return IS_ENABLED(CONFIG_HAVE_MOVE_PMD) ||
+ IS_ENABLED(CONFIG_HAVE_MOVE_PUD);
+}
+#endif
+
#ifdef CONFIG_HAVE_MOVE_PMD
static bool move_normal_pmd(struct vm_area_struct *vma, unsigned long old_addr,
unsigned long new_addr, pmd_t *old_pmd, pmd_t *new_pmd)
@@ -217,6 +226,8 @@ static bool move_normal_pmd(struct vm_ar
struct mm_struct *mm = vma->vm_mm;
pmd_t pmd;
+ if (!arch_supports_page_table_move())
+ return false;
/*
* The destination pmd shouldn't be established, free_pgtables()
* should have released it.
@@ -284,6 +295,8 @@ static bool move_normal_pud(struct vm_ar
struct mm_struct *mm = vma->vm_mm;
pud_t pud;
+ if (!arch_supports_page_table_move())
+ return false;
/*
* The destination pud shouldn't be established, free_pgtables()
* should have released it.
_
Patches currently in -mm which might be from aneesh.kumar@xxxxxxxxxxxxx are
mm-mremap-allow-arch-runtime-override.patch
powerpc-book3s64-mm-update-flush_tlb_range-to-flush-page-walk-cache.patch
powerpc-mm-enable-have_move_pmd-support.patch
