The patch titled
Subject: mm/nds32: use general page fault accounting
has been added to the -mm tree. Its filename is
mm-nds32-use-general-page-fault-accounting.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-nds32-use-general-page-fault-accounting.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-nds32-use-general-page-fault-accounting.patch
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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Peter Xu <peterx@xxxxxxxxxx>
Subject: mm/nds32: use general page fault accounting
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.
Link: http://lkml.kernel.org/r/20200707225021.200906-13-peterx@xxxxxxxxxx
Signed-off-by: Peter Xu <peterx@xxxxxxxxxx>
Acked-by: Greentime Hu <green.hu@xxxxxxxxx>
Cc: Nick Hu <nickhu@xxxxxxxxxxxxx>
Cc: Vincent Chen <deanbo422@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/nds32/mm/fault.c | 19 +++----------------
1 file changed, 3 insertions(+), 16 deletions(-)
--- a/arch/nds32/mm/fault.c~mm-nds32-use-general-page-fault-accounting
+++ a/arch/nds32/mm/fault.c
@@ -121,6 +121,8 @@ void do_page_fault(unsigned long entry,
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,
@@ -206,7 +208,7 @@ good_area:
* 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
@@ -228,22 +230,7 @@ good_area:
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;
_
Patches currently in -mm which might be from peterx@xxxxxxxxxx are
mm-do-page-fault-accounting-in-handle_mm_fault.patch
mm-alpha-use-general-page-fault-accounting.patch
mm-arc-use-general-page-fault-accounting.patch
mm-arm-use-general-page-fault-accounting.patch
mm-arm64-use-general-page-fault-accounting.patch
mm-csky-use-general-page-fault-accounting.patch
mm-hexagon-use-general-page-fault-accounting.patch
mm-ia64-use-general-page-fault-accounting.patch
mm-m68k-use-general-page-fault-accounting.patch
mm-microblaze-use-general-page-fault-accounting.patch
mm-mips-use-general-page-fault-accounting.patch
mm-nds32-use-general-page-fault-accounting.patch
mm-nios2-use-general-page-fault-accounting.patch
mm-openrisc-use-general-page-fault-accounting.patch
mm-parisc-use-general-page-fault-accounting.patch
mm-powerpc-use-general-page-fault-accounting.patch
mm-riscv-use-general-page-fault-accounting.patch
mm-s390-use-general-page-fault-accounting.patch
mm-sh-use-general-page-fault-accounting.patch
mm-sparc32-use-general-page-fault-accounting.patch
mm-sparc64-use-general-page-fault-accounting.patch
mm-x86-use-general-page-fault-accounting.patch
mm-xtensa-use-general-page-fault-accounting.patch
mm-clean-up-the-last-pieces-of-page-fault-accountings.patch
mm-gup-remove-task_struct-pointer-for-all-gup-code.patch
