Contains information about memory type range registers
/proc/mtrr is a special file in the Linux kernel that provides information about the
Memory Type Range Registers (MTRRs). MTRRs are a feature of x86 and x86-64 processors that allow the CPU to access
memory regions with different caching strategies. This can enhance the performance of your system, especially when
running memory-intensive applications.
/proc/mtrr file contains the current configuration of your system's MTRRs. Each line in the file represents a
different MTRR setting.
For example, you might see something like this when you view the contents of
reg00: base=0x0 ( 0MB), size= 2048MB, count=1: write-back
reg01: base=0x80000000 (2048MB), size= 1024MB, count=1: write-back
reg02: base=0xc0000000 (3072MB), size= 256MB, count=1: write-back
reg02 are individual MTRR registers. The
base value shows the starting address of the
memory region, and the
size value shows the size of the memory region in megabytes (MB). The
count value indicates
how many times the setting is used. The
write-back at the end of each line is the caching strategy used for the memory
/proc/mtrr file is important for understanding and configuring your system's memory caching. Properly configured
MTRRs can significantly improve system performance. This is especially important for servers running large databases or
other memory-intensive applications.
To view the contents of
/proc/mtrr, you can use the
To change the MTRR settings, you must have root privileges and use the
echo command. For
example, you might use a command like this to add a new MTRR setting:
echo "base=0x100000000 size=0x80000000 type=write-back" > /proc/mtrr
This command adds a new memory region starting at base address
0x100000000 with a size of
0x80000000 (or about 2GB),
write-back caching strategy.
If you're experiencing performance issues on your server, the
/proc/mtrr file can help you diagnose the problem.
Incorrect or inefficient MTRR settings can cause poor memory performance, leading to slow application response times or
even system crashes.
For example, if you see a lot of
uncachable entries in
/proc/mtrr, this might indicate that your system is not using
its memory efficiently. Similarly, if you see overlapping or conflicting MTRR entries, this can also cause performance
/proc/mtrr file is a powerful tool for understanding and configuring your system's memory performance. By properly
configuring your MTRRs, you can optimize your server's performance and ensure that your applications run smoothly.
Remember to always be careful when changing MTRR settings, as incorrect configurations can cause system instability or