On Mon, Jun 15, 2020 at 06:15:48PM -0400, Peter Xu wrote: > Use the new mm_fault_accounting() helper for page fault accounting. > > CC: Catalin Marinas <[email protected]> > CC: Will Deacon <[email protected]> > CC: [email protected] > Signed-off-by: Peter Xu <[email protected]> > --- > arch/arm64/mm/fault.c | 17 ++--------------- > 1 file changed, 2 insertions(+), 15 deletions(-) > > diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c > index c9cedc0432d2..09af7d7a60ec 100644 > --- a/arch/arm64/mm/fault.c > +++ b/arch/arm64/mm/fault.c > @@ -484,8 +484,6 @@ static int __kprobes do_page_fault(unsigned long addr, > unsigned int esr, > addr, esr, regs); > } > > - perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, addr); > - > /* > * As per x86, we may deadlock here. However, since the kernel only > * validly references user space from well defined areas of the code, > @@ -535,20 +533,9 @@ static int __kprobes do_page_fault(unsigned long addr, > unsigned int esr, > VM_FAULT_BADACCESS)))) { > /* > * Major/minor page fault accounting is only done > - * once. If we go through a retry, it is extremely > - * likely that the page will be found in page cache at > - * that point. > + * once. > */ > - if (major) { > - current->maj_flt++; > - perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, regs, > - addr); > - } else { > - current->min_flt++; > - perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, regs, > - addr); > - } > - > + mm_fault_accounting(current, regs, address, major);
Please can you explain why it's ok to move the PERF_COUNT_SW_PAGE_FAULTS update like this? Seems like a user-visible change to me, so some justification would really help. Will
