The patch titled
Subject: riscv: mm: accelerate pagefault when badaccess
has been added to the -mm mm-unstable branch. Its filename is
riscv-mm-accelerate-pagefault-when-badaccess.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/riscv-mm-accelerate-pagefault-when-badaccess.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: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
Subject: riscv: mm: accelerate pagefault when badaccess
Date: Wed, 3 Apr 2024 16:38:03 +0800
The access_error() of vma already checked under per-VMA lock, if it is a
bad access, directly handle error, no need to retry with mmap_lock again.
Since the page faut is handled under per-VMA lock, count it as a vma lock
event with VMA_LOCK_SUCCESS.
Link: https://lkml.kernel.org/r/20240403083805.1818160-6-wangkefeng.wang@xxxxxxxxxx
Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
Reviewed-by: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Cc: Albert Ou <aou@xxxxxxxxxxxxxxxxx>
Cc: Alexander Gordeev <agordeev@xxxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: Gerald Schaefer <gerald.schaefer@xxxxxxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Nicholas Piggin <npiggin@xxxxxxxxx>
Cc: Palmer Dabbelt <palmer@xxxxxxxxxxx>
Cc: Paul Walmsley <paul.walmsley@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Russell King <linux@xxxxxxxxxxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/riscv/mm/fault.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
--- a/arch/riscv/mm/fault.c~riscv-mm-accelerate-pagefault-when-badaccess
+++ a/arch/riscv/mm/fault.c
@@ -292,7 +292,10 @@ void handle_page_fault(struct pt_regs *r
if (unlikely(access_error(cause, vma))) {
vma_end_read(vma);
- goto lock_mmap;
+ count_vm_vma_lock_event(VMA_LOCK_SUCCESS);
+ tsk->thread.bad_cause = SEGV_ACCERR;
+ bad_area_nosemaphore(regs, code, addr);
+ return;
}
fault = handle_mm_fault(vma, addr, flags | FAULT_FLAG_VMA_LOCK, regs);
_
Patches currently in -mm which might be from wangkefeng.wang@xxxxxxxxxx are
mm-backing-dev-use-group-allocation-free-of-per-cpu-counters-api.patch
mm-remove-__set_page_dirty_nobuffers.patch
arm64-mm-cleanup-__do_page_fault.patch
arm64-mm-accelerate-pagefault-when-vm_fault_badaccess.patch
arm-mm-accelerate-pagefault-when-vm_fault_badaccess.patch
powerpc-mm-accelerate-pagefault-when-badaccess.patch
riscv-mm-accelerate-pagefault-when-badaccess.patch
s390-mm-accelerate-pagefault-when-badaccess.patch
x86-mm-accelerate-pagefault-when-badaccess.patch
