Unverified Commit ddbf1dbd authored by openeuler-ci-bot's avatar openeuler-ci-bot Committed by Gitee
Browse files

!10814 sched/cputime: Fix mul_u64_u64_div_u64() precision for cputime 

Merge Pull Request from: @ci-robot 
 
PR sync from: Zheng Zucheng <zhengzucheng@huawei.com>
https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/HVG3UFUOYYO2OSFIYEYCUOUZNJ4NYIAZ/ 
 
https://gitee.com/openeuler/kernel/issues/IAIN7D 
 
Link:https://gitee.com/openeuler/kernel/pulls/10814

 

Reviewed-by: default avatarYang Yingliang <yangyingliang@huawei.com>
Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
parents 4e6a3367 afa672a0

kernel/sched/cputime.c

+6 −0
Original line number Diff line number Diff line
@@ -579,6 +579,12 @@ void cputime_adjust(struct task_cputime *curr, struct prev_cputime *prev, 
	}



	stime = mul_u64_u64_div_u64(stime, rtime, stime + utime);

	/*

	 * Because mul_u64_u64_div_u64() can approximate on some

	 * achitectures; enforce the constraint that: a*b/(b+c) <= a.

	 */

	if (unlikely(stime > rtime))

		stime = rtime;



update:

	/*