M*P
发帖数: 6456 | 1 用
$time ./myproject &
结果是
real 40m30.487s
user 31m3.504s
sys 0m28.169s
貌似后两个加起来跟第一个差8m
这是咋回事？ |
S*A
发帖数: 7142 | 2 It is normal. Read the manual about what this time means.
【在 M*P 的大作中提到】
: 用
: $time ./myproject &
: 结果是
: real 40m30.487s
: user 31m3.504s
: sys 0m28.169s
: 貌似后两个加起来跟第一个差8m
: 这是咋回事？
|
M*P
发帖数: 6456 | 3 没找到
【在 S*A 的大作中提到】
: It is normal. Read the manual about what this time means.
|
S*A
发帖数: 7142 | 4 sign. user is just time spend on user mode. sys is time spend on
kernel mode. real is the real clock time.
If your program is waiting for some thing(disk/network), or the
system is running some other task. The the time spend on user
is small than the real time.
real time == user time only happen when kernel pretty much only
schedule one process (taking 100% CPU) at the user space.
SMP is a different story, in SMP case you can see user time > real
time because running on two different processor.
【在 M*P 的大作中提到】
: 没找到
|
