I know that jiffies length is selected at kernel compile time and it is defaulted to 250 (4ms). Source: man 7 time - The Software Clock, HZ, and Jiffies
I wonder what happens inside a jiffy. What are the conditions to increase the value of utime or stime in /proc/pid/stat?
I know that jiffies length is selected at kernel compile time and it is defaulted to 250 (4ms). Source: man 7 time - The Software Clock, HZ, and Jiffies
I wonder what happens inside a jiffy. What are the conditions to increase the value of utime or stime in /proc/pid/stat?
from here:
The value of HZ varies across kernel versions and
hardware platforms. On i386
the situation is as follows: on kernels up to and including 2.4.x, HZ was 100,
giving a jiffy value of 0.01 seconds; starting with 2.6.0, HZ was raised to
1000, giving a jiffy of 0.001 seconds.
When I run my Virtual Machine with Gentoo as guest, I have found that there is considerable overhead coming from tick_periodic function.( this is the function which runs on every timer interrupt).This function updates a global jiffy using write_seqlocks which leads to the overhead.
I was going through a serial program and I observed that they use select() before using read(). Why exactly is this required. Why cant we just directly call read() and check if it fails or not ?
Turning a bunch of text files into nicely-formatted online documentation can be a real chore, unless you use a helper tool like d.
Hi
clock_getres(clockid_t clock_id, struct timespec *res);
I cant understand what is the mining of the return value (*res) from clock_getres function.
1. what is that resolution ?
2. how can I use it ?
3. if clock_getres function return 999958 in *res, what its mean ?
4.
Hi All,
We need to create the custom function to pass the parameter is date.if it is valid return 1 else 0
return should be 1
Code:
select is_date('2012-09-17');
return should be 0
Code:
select is_date('2012-79-17');
Thanks
hmm must be stuff missing from my waldorf version as i ran the command rebuild-my-grub-iso and got /usr/bin/grub-mkrescue: 323: /usr/bin/grub-mkrescue: xorriso: not foundI installed xorriso and the grub.iso was made, thanks will now put it on usb