The patch titled
Subject: LoongArch: update local TLB if PTE entry exists
has been added to the -mm mm-unstable branch. Its filename is
loongarch-update-local-tlb-if-pte-entry-exists.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/loongarch-update-local-tlb-if-pte-entry-exists.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: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>
Subject: LoongArch: update local TLB if PTE entry exists
Date: Thu, 29 Sep 2022 19:23:18 +0800
Currently, the implementation of update_mmu_tlb() is empty if
__HAVE_ARCH_UPDATE_MMU_TLB is not defined. Then if two threads
concurrently fault at the same page, the second thread that did not win
the race will give up and do nothing. In the LoongArch architecture, this
second thread will trigger another fault, and only updates its local TLB.
Instead of triggering another fault, it's better to implement
update_mmu_tlb() to directly update the local TLB of the second thread.
Just do it.
Link: https://lkml.kernel.org/r/20220929112318.32393-3-zhengqi.arch@xxxxxxxxxxxxx
Signed-off-by: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>
Suggested-by: Bibo Mao <maobibo@xxxxxxxxxxx>
Acked-by: Huacai Chen <chenhuacai@xxxxxxxxxxx>
Cc: Chris Zankel <chris@xxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Max Filippov <jcmvbkbc@xxxxxxxxx>
Cc: Muchun Song <songmuchun@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
--- a/arch/loongarch/include/asm/pgtable.h~loongarch-update-local-tlb-if-pte-entry-exists
+++ a/arch/loongarch/include/asm/pgtable.h
@@ -412,6 +412,9 @@ static inline void update_mmu_cache(stru
__update_tlb(vma, address, ptep);
}
+#define __HAVE_ARCH_UPDATE_MMU_TLB
+#define update_mmu_tlb update_mmu_cache
+
static inline void update_mmu_cache_pmd(struct vm_area_struct *vma,
unsigned long address, pmd_t *pmdp)
{
_
Patches currently in -mm which might be from zhengqi.arch@xxxxxxxxxxxxx are
mm-introduce-common-struct-mm_slot.patch
mm-thp-convert-to-use-common-struct-mm_slot.patch
ksm-remove-redundant-declarations-in-ksmh.patch
ksm-add-the-ksm-prefix-to-the-names-of-the-ksm-private-structures.patch
ksm-convert-ksm_mm_slotmm_list-to-ksm_mm_slotmm_node.patch
ksm-convert-ksm_mm_slotlink-to-ksm_mm_slothash.patch
ksm-convert-to-use-common-struct-mm_slot.patch
mm-use-update_mmu_tlb-on-the-second-thread.patch
loongarch-update-local-tlb-if-pte-entry-exists.patch
