[PATCH v4 23/26] mm/x86: Use general page fault accounting

From: Peter Xu
Date: Tue Jun 30 2020 - 16:46:13 EST


Use the general page fault accounting by passing regs into handle_mm_fault().

CC: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
CC: Andy Lutomirski <luto@xxxxxxxxxx>
CC: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
CC: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CC: Ingo Molnar <mingo@xxxxxxxxxx>
CC: Borislav Petkov <bp@xxxxxxxxx>
CC: x86@xxxxxxxxxx
CC: H. Peter Anvin <hpa@xxxxxxxxx>
Signed-off-by: Peter Xu <peterx@xxxxxxxxxx>
---
arch/x86/mm/fault.c | 17 ++---------------
1 file changed, 2 insertions(+), 15 deletions(-)

diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index fe3ca00eb121..9ac80bb87781 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -1140,7 +1140,7 @@ void do_user_addr_fault(struct pt_regs *regs,
struct vm_area_struct *vma;
struct task_struct *tsk;
struct mm_struct *mm;
- vm_fault_t fault, major = 0;
+ vm_fault_t fault;
unsigned int flags = FAULT_FLAG_DEFAULT;

tsk = current;
@@ -1292,8 +1292,7 @@ void do_user_addr_fault(struct pt_regs *regs,
* userland). The return to userland is identified whenever
* FAULT_FLAG_USER|FAULT_FLAG_KILLABLE are both set in flags.
*/
- fault = handle_mm_fault(vma, address, flags, NULL);
- major |= fault & VM_FAULT_MAJOR;
+ fault = handle_mm_fault(vma, address, flags, regs);

/* Quick path to respond to signals */
if (fault_signal_pending(fault, regs)) {
@@ -1320,18 +1319,6 @@ void do_user_addr_fault(struct pt_regs *regs,
return;
}

- /*
- * Major/minor page fault accounting. If any of the events
- * returned VM_FAULT_MAJOR, we account it as a major fault.
- */
- if (major) {
- tsk->maj_flt++;
- perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, regs, address);
- } else {
- tsk->min_flt++;
- perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, regs, address);
- }
-
check_v8086_mode(regs, address, tsk);
}
NOKPROBE_SYMBOL(do_user_addr_fault);
--
2.26.2