Timeline for virtual addressing in device drivers
Current License: CC BY-SA 4.0
7 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Nov 5, 2019 at 12:47 | comment | added | dave | Sure, but that does not fit the conventional paradigm where the user code decides where it wants the data: read(file, buffer, length) | |
| Nov 5, 2019 at 8:25 | comment | added | JeremyP | @another-dave Operating systems often have the ability to wire specific physical address ranges into the kernel address space. Option c is not necessarily inefficient. You can map the pages directly into user space. | |
| Nov 4, 2019 at 11:35 | answer | added | lvd | timeline score: 2 | |
| Nov 2, 2019 at 13:25 | comment | added | dave | Doesn't any decent system with paged virtual memory require either (a) bus-address virtualization, or (b) device controllers that have their own scatter-gather mechanisms. Otherwise you're left with (c) I/O into physically-contiguous buffers with data copy into the user-space not-necessarily-contiguous buffers. Solution (a) seems like it's cheaper than (b) and more efficient than (c). | |
| Nov 1, 2019 at 22:12 | answer | added | dave | timeline score: 7 | |
| Nov 1, 2019 at 20:55 | review | First posts | |||
| Nov 2, 2019 at 3:03 | |||||
| Nov 1, 2019 at 20:53 | history | asked | Stefan Skoglund | CC BY-SA 4.0 |