Perfmon question

[wacki]

So i opened up perfom and I see 3 lines. Memory, physical disc, processor. I get an explanation for the memory and I see this:


"Pages/sec is the rate at which pages are read from or written to disk to resolve hard page faults. This counter is a primary indicator of the kinds of faults that cause system-wide delays. It is the sum of Memory\\Pages Input/sec and Memory\\Pages Output/sec. It is counted in numbers of pages, so it can be compared to other counts of pages, such as Memory\\Page Faults/sec, without conversion. It includes pages retrieved to satisfy faults in the file system cache (usually requested by applications) non-cached mapped memory files."

Ok, so I can code in C++ and I know all about transistors, pointers, etc but I have no idea what a page is. Anyone want to help clarify this for me?

 

[Smilin]

This is a heavy topic so you'll need to do some reading elsewhere.

Memory in windows is stored in 4k pages. These are pulled in from disk and pushed out to disk as needed by the application and as needed by the OS to juggle all the apps that are running. Your application is unaware of all of this it simply sees 2gigs of user mode address space and 2gigs of kernel address space some of which may be real memory, some may be pagefile on disk.

Google Virtual Memory for Windows.


edit:
A "page" can also be a verb meaning to move a page(noun) of memory in our out to disk.

 

[Nothinman]

Ok, so I can code in C++ and I know all about transistors, pointers, etc but I have no idea what a page is. Anyone want to help clarify this for me?

A page is just 1 unit of memory. On 32-bit systems this amounts to 4K. Page is also a verb meaning to read or write 1 page worth of data from one location to another.

A soft page fault will result in just the pagetables being updated to point one virtual page to another physical page, a hard page fault will result in data being read from disk into physical memory.