Clock

[zhe]

After reading the project description few times, I am still confused about
updating the clock for paging out, how and when do we update the clock for
each page?

Thx

Zhe

[Iulian Neamtiu]

The algorithm is in the recitation slides. You need to write a function
(you'll call it in the page fault handler) that walks thru the
pageable pages and
- updates the clock if the page was accessed (set clock to g_numTicks)
- sets the accessed bit to 1


Iulian

Post by zhe
After reading the project description few times, I am still confused about
updating the clock for paging out, how and when do we update the clock for
each page?
Thx
Zhe

[William Francis Cladek]

I assume you mean to say it sets the accessed bit of each page to 0...

Post by Iulian Neamtiu
The algorithm is in the recitation slides. You need to write a function
(you'll call it in the page fault handler) that walks thru the
pageable pages and
- updates the clock if the page was accessed (set clock to g_numTicks)
- sets the accessed bit to 1
Iulian

[Iulian Neamtiu]

Post by William Francis Cladek
I assume you mean to say it sets the accessed bit of each page to 0...

Yes, set the accessed bit to 0; sorry about that.


Iulian

Post by William Francis Cladek

Post by Iulian Neamtiu
The algorithm is in the recitation slides. You need to write a function
(you'll call it in the page fault handler) that walks thru the
pageable pages and
- updates the clock if the page was accessed (set clock to g_numTicks)
- sets the accessed bit to 1
Iulian