Messages in this thread Patch in this message | | | From | Peter Xu <> | Subject | [PATCH 12/26] mm/nds32: Use general page fault accounting | Date | Fri, 19 Jun 2020 12:05:24 -0400 |
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Use the general page fault accounting by passing regs into handle_mm_fault(). It naturally solve the issue of multiple page fault accounting when page fault retry happened.
Fix PERF_COUNT_SW_PAGE_FAULTS perf event manually for page fault retries, by moving it before taking mmap_sem.
CC: Nick Hu <nickhu@andestech.com> CC: Greentime Hu <green.hu@gmail.com> CC: Vincent Chen <deanbo422@gmail.com> Signed-off-by: Peter Xu <peterx@redhat.com> --- arch/nds32/mm/fault.c | 19 +++---------------- 1 file changed, 3 insertions(+), 16 deletions(-)
diff --git a/arch/nds32/mm/fault.c b/arch/nds32/mm/fault.c index 22527129025c..e7344440623c 100644 --- a/arch/nds32/mm/fault.c +++ b/arch/nds32/mm/fault.c @@ -122,6 +122,8 @@ void do_page_fault(unsigned long entry, unsigned long addr, if (unlikely(faulthandler_disabled() || !mm)) goto no_context; + 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, @@ -207,7 +209,7 @@ void do_page_fault(unsigned long entry, unsigned long addr, * the fault. */ - fault = handle_mm_fault(vma, addr, flags, NULL); + fault = handle_mm_fault(vma, addr, flags, regs); /* * If we need to retry but a fatal signal is pending, handle the @@ -229,22 +231,7 @@ void do_page_fault(unsigned long entry, unsigned long addr, goto bad_area; } - /* - * Major/minor page fault accounting is only done on the initial - * attempt. If we go through a retry, it is extremely likely that the - * page will be found in page cache at that point. - */ - perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, addr); if (flags & FAULT_FLAG_ALLOW_RETRY) { - if (fault & VM_FAULT_MAJOR) { - tsk->maj_flt++; - perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, - 1, regs, addr); - } else { - tsk->min_flt++; - perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, - 1, regs, addr); - } if (fault & VM_FAULT_RETRY) { flags |= FAULT_FLAG_TRIED; -- 2.26.2
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