lkml.org 
[lkml]   [2020]   [Jun]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 18/25] mm/riscv: Use mm_fault_accounting()
Date
Use the new mm_fault_accounting() helper for page fault accounting.

Avoid doing page fault accounting multiple times if the page fault is retried.

CC: Paul Walmsley <paul.walmsley@sifive.com>
CC: Palmer Dabbelt <palmer@dabbelt.com>
CC: Albert Ou <aou@eecs.berkeley.edu>
CC: linux-riscv@lists.infradead.org
Signed-off-by: Peter Xu <peterx@redhat.com>
---
arch/riscv/mm/fault.c | 21 +++------------------
1 file changed, 3 insertions(+), 18 deletions(-)

diff --git a/arch/riscv/mm/fault.c b/arch/riscv/mm/fault.c
index be84e32adc4c..9262338614d1 100644
--- a/arch/riscv/mm/fault.c
+++ b/arch/riscv/mm/fault.c
@@ -30,7 +30,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs)
struct vm_area_struct *vma;
struct mm_struct *mm;
unsigned long addr, cause;
- unsigned int flags = FAULT_FLAG_DEFAULT;
+ unsigned int flags = FAULT_FLAG_DEFAULT, major = 0;
int code = SEGV_MAPERR;
vm_fault_t fault;

@@ -65,9 +65,6 @@ asmlinkage void do_page_fault(struct pt_regs *regs)

if (user_mode(regs))
flags |= FAULT_FLAG_USER;
-
- perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, addr);
-
retry:
down_read(&mm->mmap_sem);
vma = find_vma(mm, addr);
@@ -111,6 +108,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs)
* the fault.
*/
fault = handle_mm_fault(vma, addr, flags);
+ major |= fault & VM_FAULT_MAJOR;

/*
* If we need to retry but a fatal signal is pending, handle the
@@ -128,21 +126,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs)
BUG();
}

- /*
- * 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.
- */
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;

@@ -156,6 +140,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs)
}

up_read(&mm->mmap_sem);
+ mm_fault_accounting(tsk, regs, addr, major);
return;

/*
--
2.26.2
\
 
 \ /
  Last update: 2020-06-16 00:17    [W:0.328 / U:0.028 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site