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-1
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2answers
33 views

How do I enable DMA on a SATA controller?

I don't see any section "IDE ATA/ATAPI controllers" in device manager: What does this mean? and Can I know on which devices DMA can be enabled?
1
vote
0answers
52 views

IOMMU cache coherency

In today's x86/x64 motherboards there can be found IOMMU's from Intel and AMD. They allow peripheral devices to perform DMA (direct memory access) operations into system RAM using virtual instead of ...
0
votes
0answers
43 views

When doing IDE DMA on x86, can other CPUs access the memory?

I am unfamiliar with hardware. I am studying the IDE disk I/O and DMA on x86. I want to know that when doing a IDE disk I/O with DMA, can other CPUs access the memory (or exactly, the same memory ...
2
votes
1answer
121 views

Virtual Memory and MMU: when are they used and when not?

I'm wondering about how a Virtual Memory system could be managed alongside with a MMU when there's the need to mantain some "fixed" addresses in the address space. For example, when a machine boots ...
0
votes
0answers
225 views

PCI Express BAR memory mapping basic understanding

I am trying to understand how PCI Express works so i can write a windows driver that can read and write to a custom PCI Express device with no on-board memory. I understand that the Base Address ...
0
votes
1answer
106 views

How to stress the Windows XP kernel?

We have intermittant problems with writing DVDs where the writing process fails. We suspect that the problem is happening when the DVD driver switches from DMA mode to PIO mode and then in this mode ...
2
votes
1answer
82 views

Debian loses harddisk on bootup 4 times and then boots. Why?

Dmesg Dump: http://paste.debian.net/44975 at time 32.832045 That error is delaying my boot process significantly. Does anyone know what this is about? Devices: Maxtor IDE drive with new cable on ...
0
votes
1answer
222 views

Debian Wheezy, old computer, DMA read error, scales modes down until PIO

I got an old computer that I wanted to install debian wheezy on. Well that works but,at every bootup I get those errors: ata1.00: failed command: READ DMA when it happens the kernel softresets the ...
2
votes
1answer
490 views

Kernel bypass possible with non-specialised NIC?

Is it possible to perform kernel bypass and have a NIC send data to the user space (where I will write my network stack) with no copying, without having to purchase a specialised Solarflare etc NIC?
-1
votes
2answers
67 views

DMA issue, keyboard about to die?

I have this message when I boot up debian and it takes a bit before booting when it reaches this error message: https://dl.dropboxusercontent.com/u/762638/Files/Images/dma_issue.jpg If I mount the ...
1
vote
1answer
39 views

IDE DMA sector numbering

I'm just playing around with the QEMU system emulator, and taking a look at the IDE disk emulation, specifically at the DMA disk accesses. I'm a little confused as to how DMA requests are actually ...
0
votes
0answers
57 views

Memory managemnt Linux 3.0+

using Ubuntu 12.04 with 2 Gb DDR3 ram with 3.2.0-39-generic free -k total used free shared buffers cached Mem: 2012040 1875968 136072 0 ...
3
votes
2answers
645 views

When a disk read or disk write occurs, where does the data go?

I understand that there is such a thing as a disk controller which contains a buffer, but was wondering if the CPU reads directly from this buffer, or whether the data must first go to a specific ...