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authorKefeng Wang <wangkefeng.wang@huawei.com>2024-04-03 11:38:04 +0300
committerAndrew Morton <akpm@linux-foundation.org>2024-04-26 06:56:39 +0300
commit82b7a618397c80736506c05d9add4aaea91297e8 (patch)
tree457bd8afe4b0f8562e26a3c25a1a56949f467d47
parentcd1c91b8548372ced64a01eb6eef67b539506238 (diff)
downloadlinux-82b7a618397c80736506c05d9add4aaea91297e8.tar.xz
s390: mm: accelerate pagefault when badaccess
The vm_flags 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/20240403083805.1818160-7-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
-rw-r--r--arch/s390/mm/fault.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c
index 0c66b32e0f9f..65747f15dbec 100644
--- a/arch/s390/mm/fault.c
+++ b/arch/s390/mm/fault.c
@@ -325,7 +325,8 @@ static void do_exception(struct pt_regs *regs, int access)
goto lock_mmap;
if (!(vma->vm_flags & access)) {
vma_end_read(vma);
- goto lock_mmap;
+ count_vm_vma_lock_event(VMA_LOCK_SUCCESS);
+ return handle_fault_error_nolock(regs, SEGV_ACCERR);
}
fault = handle_mm_fault(vma, address, flags | FAULT_FLAG_VMA_LOCK, regs);
if (!(fault & (VM_FAULT_RETRY | VM_FAULT_COMPLETED)))