| Message ID | 20200630204601.39591-1-peterx@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | mm: Page fault accounting cleanups | expand |
On 6/30/20 1:46 PM, Peter Xu wrote: > Use the general page fault accounting by passing regs into handle_mm_fault(). ... > - /* > - * 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); > } I did a quick grep and it wasn't obvious to me how PERF_COUNT_SW_PAGE_FAULTS_MIN/MAJ get bumped in the handle_mm_fault() path. Are you sure they get set?
Hi, Dave, On Wed, Jul 01, 2020 at 08:35:40AM -0700, Dave Hansen wrote: > On 6/30/20 1:46 PM, Peter Xu wrote: > > Use the general page fault accounting by passing regs into handle_mm_fault(). > ... > > - /* > > - * 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); > > } > > I did a quick grep and it wasn't obvious to me how > PERF_COUNT_SW_PAGE_FAULTS_MIN/MAJ get bumped in the handle_mm_fault() path. > > Are you sure they get set? Sorry for missing the context. This patch is based on the 1st patch of the same series: https://lore.kernel.org/lkml/20200630204504.38516-1-peterx@redhat.com/ Both of them are set there. Thanks,
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);
Use the general page fault accounting by passing regs into handle_mm_fault(). CC: Dave Hansen <dave.hansen@linux.intel.com> CC: Andy Lutomirski <luto@kernel.org> CC: Peter Zijlstra <peterz@infradead.org> CC: Thomas Gleixner <tglx@linutronix.de> CC: Ingo Molnar <mingo@redhat.com> CC: Borislav Petkov <bp@alien8.de> CC: x86@kernel.org CC: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Peter Xu <peterx@redhat.com> --- arch/x86/mm/fault.c | 17 ++--------------- 1 file changed, 2 insertions(+), 15 deletions(-)