diff options
| author | Yang Yang <yang.yang29@zte.com.cn> | 2022-06-01 15:55:25 -0700 |
|---|---|---|
| committer | akpm <akpm@linux-foundation.org> | 2022-06-01 15:55:25 -0700 |
| commit | 662ce1dc9caf493c309200edbe38d186f1ea20d0 (patch) | |
| tree | e49eeda0a61590b5843d47d1be17dbb18cf3aaa1 /mm/hugetlb.c | |
| parent | 54eb8462f21fb170a05ad64620f0d8d0cf2b7fb5 (diff) | |
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/hugetlb.c')
| -rw-r--r-- | mm/hugetlb.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 7c468ac1d069..a57e1be41401 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -32,6 +32,7 @@ #include <linux/cma.h> #include <linux/migrate.h> #include <linux/nospec.h> +#include <linux/delayacct.h> #include <asm/page.h> #include <asm/pgalloc.h> @@ -5230,6 +5231,8 @@ static vm_fault_t hugetlb_wp(struct mm_struct *mm, struct vm_area_struct *vma, pte = huge_ptep_get(ptep); old_page = pte_page(pte); + delayacct_wpcopy_start(); + retry_avoidcopy: /* * If no-one else is actually using this page, we're the exclusive @@ -5240,6 +5243,8 @@ retry_avoidcopy: page_move_anon_rmap(old_page, vma); if (likely(!unshare)) set_huge_ptep_writable(vma, haddr, ptep); + + delayacct_wpcopy_end(); return 0; } VM_BUG_ON_PAGE(PageAnon(old_page) && PageAnonExclusive(old_page), @@ -5309,6 +5314,7 @@ retry_avoidcopy: * race occurs while re-acquiring page table * lock, and our job is done. */ + delayacct_wpcopy_end(); return 0; } @@ -5367,6 +5373,8 @@ out_release_old: put_page(old_page); spin_lock(ptl); /* Caller expects lock to be held */ + + delayacct_wpcopy_end(); return ret; } |