My goal is to read in stale and outdated values of memory without cache-coherence. I have attempted to use prefetchnta to perform a non-temporal load, but it failed to fetch outdated values. I am looking into performing some kind of Streaming Memory-to-Memory Direct-Memory-Access, but am having a little trouble due to the overwhelming amount of background knowledge required to proceed
Tag: caching
How to disable cache memory in kernel modules
I’am currently trying to develop a Linux driver to use a custom module developed in FPGA. For that, I use a Xilinx Zynq SoC with a Linux distribution that runs on the 2 ARM cores and my VHDL modules are implemented on the FPGA part, but this is not really important to understand my problem. My FPGA module writes directly
What are “Positive entries” and “Negative entries” in NSCD (Named Service Cache Deamon) for FreeIPA
The “Positive entries” and “Negative entries” stats are in the nscd -g command under “hosts cache” section. From the nscd.conf manual, I see that “positive entries are successful queries in the specified cache” and “negative entries (unsuccessful queries) in the specified cache”. But, how can a unsuccessful query(negative entry) in cache have hits(cache hits on negative entries), when the query
ARM: Disabling MMU and updating PC
In short, I would like to shut down all MMU (and cache) operations in a Linux context (from inside the Kernel), for debug purposes, just to run some tests. To be perfectly clear, I don’t intend that my system still be functional after that. About my setup: I’m currently fiddling with a Freescale Vybrid (VF610) – which integrates a Cortex
Disabling disk cache in linux
In a class project my teacher told us to make some code evaluations (C language) and to do so we need to disable the disk caching during the tests. Currently I’m using Ubuntu 12.04, how can I do this? Thanks. Answer You need root access to do this. You can run hdparm -W 0 /dev/sda command to disable write caching,