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| author | Yang Yang <yang.yang29@zte.com.cn> | 2022-06-02 01:55:25 +0300 |
|---|---|---|
| committer | akpm <akpm@linux-foundation.org> | 2022-06-02 01:55:25 +0300 |
| commit | 662ce1dc9caf493c309200edbe38d186f1ea20d0 (patch) | |
| tree | e49eeda0a61590b5843d47d1be17dbb18cf3aaa1 /mm/memory.c | |
| parent | 54eb8462f21fb170a05ad64620f0d8d0cf2b7fb5 (diff) | |
| download | linux-662ce1dc9caf493c309200edbe38d186f1ea20d0.tar.xz | |
delayacct: track delays from write-protect copy
Delay accounting does not track the delay of write-protect copy. When
tasks trigger many write-protect copys(include COW and unsharing of
anonymous pages[1]), it may spend a amount of time waiting for them. To
get the delay of tasks in write-protect copy, could help users to evaluate
the impact of using KSM or fork() or GUP.
Also update tools/accounting/getdelays.c:
/ # ./getdelays -dl -p 231
print delayacct stats ON
listen forever
PID 231
CPU count real total virtual total delay total delay average
6247 1859000000 2154070021 1674255063 0.268ms
IO count delay total delay average
0 0 0ms
SWAP count delay total delay average
0 0 0ms
RECLAIM count delay total delay average
0 0 0ms
THRASHING count delay total delay average
0 0 0ms
COMPACT count delay total delay average
3 72758 0ms
WPCOPY count delay total delay average
3635 271567604 0ms
[1] commit 31cc5bc4af70("mm: support GUP-triggered unsharing of anonymous pages")
Link: https://lkml.kernel.org/r/20220409014342.2505532-1-yang.yang29@zte.com.cn
Signed-off-by: Yang Yang <yang.yang29@zte.com.cn>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Jiang Xuexin <jiang.xuexin@zte.com.cn>
Reviewed-by: Ran Xiaokai <ran.xiaokai@zte.com.cn>
Reviewed-by: wangyong <wang.yong12@zte.com.cn>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/memory.c')
| -rw-r--r-- | mm/memory.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/mm/memory.c b/mm/memory.c index 21dadf03f089..7a089145cad4 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3090,6 +3090,8 @@ static vm_fault_t wp_page_copy(struct vm_fault *vmf) int page_copied = 0; struct mmu_notifier_range range; + delayacct_wpcopy_start(); + if (unlikely(anon_vma_prepare(vma))) goto oom; @@ -3114,6 +3116,8 @@ static vm_fault_t wp_page_copy(struct vm_fault *vmf) put_page(new_page); if (old_page) put_page(old_page); + + delayacct_wpcopy_end(); return 0; } } @@ -3220,12 +3224,16 @@ static vm_fault_t wp_page_copy(struct vm_fault *vmf) free_swap_cache(old_page); put_page(old_page); } + + delayacct_wpcopy_end(); return (page_copied && !unshare) ? VM_FAULT_WRITE : 0; oom_free_new: put_page(new_page); oom: if (old_page) put_page(old_page); + + delayacct_wpcopy_end(); return VM_FAULT_OOM; } |