A page, memory page, or virtual page is a fixed-length contiguous block of virtual memory, and it is the smallest unit of data for the following:
memory allows a page that does not currently reside in main memory to
be addressed and used. If a program tries to access a location in such a
page, an exception called a page fault
is generated. The hardware or operating system is notified and loads
the required page from the auxiliary store automatically. A program
addressing the memory has no knowledge of a page fault or a process
following it. Thus a program can address more (virtual) RAM than
physically exists in the computer.
A transfer of pages between main memory and an auxiliary store, such as a hard disk drive, is referred to as paging or swapping.
Page size trade-off
Page size is usually determined by processor architecture. Traditionally, pages in a system had uniform size, for example 4096 bytes.
However, processor designs often allow two or more, sometimes
simultaneous, page sizes due to the benefits and penalties. There are
several points that can factor into choosing the best page size.
Page size versus page table size
A system with a smaller page size uses more pages, requiring a page table that occupies more space. For example, if a 232 virtual address space is mapped to 4KB (212 bytes) pages, the number of virtual pages is 220 =( 232 / 212). However, if the page size is increased to 32KB (215 bytes), only 217
pages are required. A multi-level paging algorithm can decrease the
memory cost of allocating a large page table for each process by further
dividing the page table up into smaller tables, effectively paging the
Page size versus TLB usage
every access to memory must be mapped from virtual to physical address,
reading the page table every time can be quite costly. Therefore, a
very fast kind of cache, the Translation Lookaside Buffer (TLB), is often used. The TLB is of limited size, and when it cannot satisfy a given request (a TLB miss)
the page tables must be searched manually (either in hardware or
software, depending on the architecture) for the correct mapping. Larger
page sizes mean that a TLB cache of the same size can keep track of
larger amounts of memory, which avoids the costly TLB misses.
Internal fragmentation of pages
do processes require the use of an exact number of pages. As a result,
the last page will likely only be partially full, wasting some amount of
memory. Larger page sizes increase the potential for wasted memory this
way, as more potentially unused portions of memory are loaded into main
memory. Smaller page sizes ensure a closer match to the actual amount
of memory required in an allocation.
As an example, assume the
page size is 1024KB. If a process allocates 1025KB, two pages must be
used, resulting in 1023KB of unused space (where one page fully consumes
1024KB and the other only 1KB).
Page size versus disk access
transferring from disk, much of the delay is caused by seek time, the
time it takes to correctly position the read/write heads above the disk
platters. Because of this, large sequential transfers are more efficient
than several smaller transfers. Transferring the same amount of data
from disk to memory often requires less time with larger pages than with
Determining the page size in a program
Most operating systems allow programs to discover the page size at runtime
...thus we see an explicit message from NATURE to the computer science industry about the HUMAN bio-computer programming schemes of Wisconsin citizens that approve of the STATE bio-assembly government policy.
Computer Earth system 370 has several formats of expression ..such as the copper-wire IBM system 370 main frame with OS/JCL SNA VTAM.
The earth geography soil / LAND at --> LAN Dat = Local Area Network Data ......thus NATURE keeps tracks of Humans and their violations ...such as DuPAGE County , Illinois.
County is a county located in the U.S. state of Illinois. Its county
seat is the city of Wheaton. This county is part of the Chicago
metropolitan area. Wikipedia
Page size Area: 337 sq miles (872.8 km²)
RAM (pronounced ramm) is an acronym for random access memory, a type of computer memory that can be accessed randomly; that is, any byte of memory ca
RAM - random access memory
RAM (pronounced ramm) is an acronym for random access memory, a type of computer memory that can be accessed randomly; that is, any byte of memory can be accessed without touching the preceding bytes. RAM is the most common type of memory found in computers and other devices, such as printers.
Types of RAM --> HUMAN bio-computer RAMPAGE --> school shooting messages for DuPage county intellectuals
There are two different types of RAM:
two types of RAM differ in the technology they use to hold data, with
DRAM being the more common type. In terms of speed, SRAM is faster. DRAM
needs to be refreshed thousands of times per second while SRAM does not
need to be refreshed, which is what makes it faster than DRAM.
supports access times of about 60 nanoseconds, SRAM can give access
times as low as 10 nanoseconds. Despite SRAM being faster, it's not as
commonly used as DRAM because it's so much more expensive. Both types of
RAM are volatile, meaning that they lose their contents when the power is turned off.
RAM, Main Memory and ROM Explained
In common usage, the term RAM is synonymous with main memory,
Thus we look at the key English language instructions used to program puppet bio-computer.
The phase ...is seen often ..in electronic stores, etc.
www.pcworld.com/article/129177/article.htmlFeb 27, 2007 – Adding RAM is often the most cost-effective upgrade you can make to speed up a sluggish computer. ... What kind of RAM works on my PC?
These instructions to the human brain ...go into 2 directions ...well-known to advertising / marketing/business teachers at universities and companies.
2) The subliminal mind bio-computer PC = Person Computer
en.wikipedia.org/wiki/MyoglobinMyoglobin is an iron- and oxygen-binding protein found in the muscle tissue of vertebrates in general and in almost all mammals. It is related to hemoglobin, ...
www.phattimes.com/myoglobin/chapter2.htmMyoglobin, an extremely compact heme protein (MW ~ 17 800), found primarily in ... A reservoir of oxygen located in the slow phasic muscle fibers, myoglobin consists of a ... In myoglobin, the heme consists of an organic part and an iron part.
en.wikibooks.org/wiki/Structural.../Protein_function/.../MyoglobinMyoglobin was the first protein whose structure was determined. ... Myoglobin, an iron-containing protein in muscle, receives oxygen from the red blood cells ...
Thus we see NATURE versus the OXYGEN atomic computer base 16 manipulators of myglobin protein and their protein thoughts.
No quality control exists with the state and federal governments around the WORLD ...the human brain electron computer exists for citizen abuse...and when something does wrong they blame it on other factors.
The Base 16 hex shooting at Virginia TECH was lousy cover-up of obvious.
The FORTRAN H computer shooting at Fort H, Killeen Texas is another cover-up.
Thus we see some pieces to a tragic puzzle.