[PATCH 22/26] mm/unicore32: Use general page fault accounting

Peter Xu
2020-06-19T16:14:00Z

retry happened.

Add the missing PERF_COUNT_SW_PAGE_FAULTS perf events too. Note, the other two
perf events (PERF_COUNT_SW_PAGE_FAULTS_[MAJ|MIN]) were done in handle_mm_fault().

CC: Guan Xuetao <gxt@pku.edu.cn>
Signed-off-by: Peter Xu <peterx@redhat.com>
---
arch/unicore32/mm/fault.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/arch/unicore32/mm/fault.c b/arch/unicore32/mm/fault.c
index 847ff24fcc2a..b272a389d977 100644
--- a/arch/unicore32/mm/fault.c
+++ b/arch/unicore32/mm/fault.c
@@ -16,6 +16,7 @@
#include <linux/page-flags.h>
#include <linux/sched/signal.h>
#include <linux/io.h>
+#include <linux/perf_event.h>

#include <asm/pgtable.h>
#include <asm/tlbflush.h>
@@ -160,7 +161,8 @@ static inline bool access_error(unsigned int fsr, struct vm_area_struct *vma)
}

static vm_fault_t __do_pf(struct mm_struct *mm, unsigned long addr,
- unsigned int fsr, unsigned int flags, struct task_struct *tsk)
+ unsigned int fsr, unsigned int flags,
+ struct task_struct *tsk, struct pt_regs *regs)
{
struct vm_area_struct *vma;
vm_fault_t fault;
@@ -186,7 +188,7 @@ static vm_fault_t __do_pf(struct mm_struct *mm, unsigned long addr,
* If for any reason at all we couldn't handle the fault, make
* sure we exit gracefully rather than endlessly redo the fault.
*/
- fault = handle_mm_fault(vma, addr & PAGE_MASK, flags, NULL);
+ fault = handle_mm_fault(vma, addr & PAGE_MASK, flags, regs);
return fault;

check_stack:
@@ -219,6 +221,8 @@ static int do_pf(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
if (!(fsr ^ 0x12))
flags |= FAULT_FLAG_WRITE;

+ 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,
@@ -244,7 +248,7 @@ static int do_pf(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
#endif
}

- fault = __do_pf(mm, addr, fsr, flags, tsk);
+ fault = __do_pf(mm, addr, fsr, flags, tsk, regs);

/* If we need to retry but a fatal signal is pending, handle the
* signal first. We do not need to release the mmap_sem because
@@ -254,10 +258,6 @@ static int do_pf(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
return 0;

if (!(fault & VM_FAULT_ERROR) && (flags & FAULT_FLAG_ALLOW_RETRY)) {
- if (fault & VM_FAULT_MAJOR)
- tsk->maj_flt++;
- else
- tsk->min_flt++;
if (fault & VM_FAULT_RETRY) {
flags |= FAULT_FLAG_TRIED;
goto retry;
--
2.26.2