From cd1c91b8548372ced64a01eb6eef67b539506238 Mon Sep 17 00:00:00 2001 From: Kefeng Wang Date: Wed, 3 Apr 2024 16:38:03 +0800 Subject: riscv: mm: accelerate pagefault when badaccess 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. [wangkefeng.wang@huawei.com: use `cause' rather than SIGSEGV, per Alexandre] Link: https://lkml.kernel.org/r/ac978061-ce1a-40a4-8b0a-61883b42bea7@huawei.com Link: https://lkml.kernel.org/r/20240403083805.1818160-6-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang Reviewed-by: Suren Baghdasaryan Reviewed-by: Alexandre Ghiti Tested-by: Alexandre Ghiti Cc: Alexander Gordeev Cc: Andy Lutomirski Cc: Catalin Marinas Cc: Christophe Leroy Cc: Dave Hansen Cc: Gerald Schaefer Cc: Michael Ellerman Cc: Nicholas Piggin Cc: Palmer Dabbelt Cc: Paul Walmsley Cc: Peter Zijlstra Cc: Russell King Cc: Will Deacon Signed-off-by: Andrew Morton --- arch/riscv/mm/fault.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'arch/riscv/mm/fault.c') diff --git a/arch/riscv/mm/fault.c b/arch/riscv/mm/fault.c index 3ba1d4dde5dd..5224f3733802 100644 --- a/arch/riscv/mm/fault.c +++ b/arch/riscv/mm/fault.c @@ -292,7 +292,10 @@ void handle_page_fault(struct pt_regs *regs) 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 = cause; + bad_area_nosemaphore(regs, SEGV_ACCERR, addr); + return; } fault = handle_mm_fault(vma, addr, flags | FAULT_FLAG_VMA_LOCK, regs); -- cgit v1.2.3-59-g8ed1b From 4c6c0020427a4547845a83f7e4d6085e16c3e24f Mon Sep 17 00:00:00 2001 From: Kefeng Wang Date: Wed, 3 Apr 2024 16:38:03 +0800 Subject: riscv: mm: accelerate pagefault when badaccess 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. Reviewed-by: Suren Baghdasaryan Signed-off-by: Kefeng Wang Reviewed-by: Alexandre Ghiti Tested-by: Alexandre Ghiti Link: https://lore.kernel.org/r/20240403083805.1818160-6-wangkefeng.wang@huawei.com Signed-off-by: Palmer Dabbelt --- arch/riscv/mm/fault.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/riscv/mm/fault.c') diff --git a/arch/riscv/mm/fault.c b/arch/riscv/mm/fault.c index 5224f3733802..b3fcf7d67efb 100644 --- a/arch/riscv/mm/fault.c +++ b/arch/riscv/mm/fault.c @@ -293,8 +293,8 @@ void handle_page_fault(struct pt_regs *regs) if (unlikely(access_error(cause, vma))) { vma_end_read(vma); count_vm_vma_lock_event(VMA_LOCK_SUCCESS); - tsk->thread.bad_cause = cause; - bad_area_nosemaphore(regs, SEGV_ACCERR, addr); + tsk->thread.bad_cause = SEGV_ACCERR; + bad_area_nosemaphore(regs, code, addr); return; } -- cgit v1.2.3-59-g8ed1b