The patch titled
Subject: MIPS: do not call flush_tlb_all when setting pmd entry
has been added to the -mm tree. Its filename is
mips-do-not-call-flush_tlb_all-when-setting-pmd-entry.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mips-do-not-call-flush_tlb_all-when-setting-pmd-entry.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mips-do-not-call-flush_tlb_all-when-setting-pmd-entry.patch
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------------------------------------------------------
From: Bibo Mao <maobibo@xxxxxxxxxxx>
Subject: MIPS: do not call flush_tlb_all when setting pmd entry
Function set_pmd_at is to set pmd entry, if tlb entry need to be flushed,
there exists pmdp_huge_clear_flush alike function before set_pmd_at is
called. So it is not necessary to call flush_tlb_all in this function.
In these scenarios, tlb for the pmd range needs to be flushed:
1. privilege degrade such as wrprotect is set on the pmd entry
2. pmd entry is cleared
3. there is exception if set_pmd_at is issued by dup_mmap, since
flush_tlb_mm is called for parent process, it is not necessary
to flush tlb in function copy_huge_pmd.
Link: http://lkml.kernel.org/r/1592990792-1923-3-git-send-email-maobibo@xxxxxxxxxxx
Signed-off-by: Bibo Mao <maobibo@xxxxxxxxxxx>
Cc: Anshuman Khandual <anshuman.khandual@xxxxxxx>
Cc: Daniel Silsby <dansilsby@xxxxxxxxx>
Cc: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Cc: Mike Rapoport <rppt@xxxxxxxxxxxxx>
Cc: Paul Burton <paulburton@xxxxxxxxxx>
Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Cc: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/mips/mm/pgtable-32.c | 1 -
arch/mips/mm/pgtable-64.c | 1 -
2 files changed, 2 deletions(-)
--- a/arch/mips/mm/pgtable-32.c~mips-do-not-call-flush_tlb_all-when-setting-pmd-entry
+++ a/arch/mips/mm/pgtable-32.c
@@ -45,7 +45,6 @@ void set_pmd_at(struct mm_struct *mm, un
pmd_t *pmdp, pmd_t pmd)
{
*pmdp = pmd;
- flush_tlb_all();
}
#endif /* defined(CONFIG_TRANSPARENT_HUGEPAGE) */
--- a/arch/mips/mm/pgtable-64.c~mips-do-not-call-flush_tlb_all-when-setting-pmd-entry
+++ a/arch/mips/mm/pgtable-64.c
@@ -100,7 +100,6 @@ void set_pmd_at(struct mm_struct *mm, un
pmd_t *pmdp, pmd_t pmd)
{
*pmdp = pmd;
- flush_tlb_all();
}
void __init pagetable_init(void)
_
Patches currently in -mm which might be from maobibo@xxxxxxxxxxx are
mm-set-page-fault-address-for-update_mmu_cache_pmd.patch
mm-huge_memoryc-update-tlb-entry-if-pmd-is-changed.patch
mips-do-not-call-flush_tlb_all-when-setting-pmd-entry.patch
