* [PATCH v5 03/25] mm/arc: Use general page fault accounting
[not found] <20200707225021.200906-1-peterx@redhat.com>
@ 2020-07-07 22:49 ` Peter Xu
0 siblings, 0 replies; only message in thread
From: Peter Xu @ 2020-07-07 22:49 UTC (permalink / raw)
To: linux-kernel, linux-mm
Cc: Andrea Arcangeli, John Hubbard, Linus Torvalds, peterx,
Vineet Gupta, Michael Ellerman, David Rientjes, Andrew Morton,
linux-snps-arc, Will Deacon, Gerald Schaefer
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: Vineet Gupta <vgupta@synopsys.com>
CC: linux-snps-arc@lists.infradead.org
Signed-off-by: Peter Xu <peterx@redhat.com>
---
arch/arc/mm/fault.c | 18 +++---------------
1 file changed, 3 insertions(+), 15 deletions(-)
diff --git a/arch/arc/mm/fault.c b/arch/arc/mm/fault.c
index 587dea524e6b..f5657cb68e4f 100644
--- a/arch/arc/mm/fault.c
+++ b/arch/arc/mm/fault.c
@@ -105,6 +105,7 @@ void do_page_fault(unsigned long address, struct pt_regs *regs)
if (write)
flags |= FAULT_FLAG_WRITE;
+ perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
retry:
mmap_read_lock(mm);
@@ -130,7 +131,7 @@ void do_page_fault(unsigned long address, struct pt_regs *regs)
goto bad_area;
}
- fault = handle_mm_fault(vma, address, flags, NULL);
+ fault = handle_mm_fault(vma, address, flags, regs);
/* Quick path to respond to signals */
if (fault_signal_pending(fault, regs)) {
@@ -155,22 +156,9 @@ void do_page_fault(unsigned long address, struct pt_regs *regs)
* Major/minor page fault accounting
* (in case of retry we only land here once)
*/
- perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
-
- if (likely(!(fault & VM_FAULT_ERROR))) {
- if (fault & VM_FAULT_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);
- }
-
+ if (likely(!(fault & VM_FAULT_ERROR)))
/* Normal return path: fault Handled Gracefully */
return;
- }
if (!user_mode(regs))
goto no_context;
--
2.26.2
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