On 2/8/06, Konstantinos Pachopoulos <kostaspaxos@xxxxxxxx> wrote: > Hi, > Are i/o data written immediately to memory and the > corresponding pages "pinned" there (locked)? or kernel > buffers are used for the i/o data first and then data > are copied to memory? Ehh, your question is not entirely clear; where would kernel buffers be if not in memory? Some kinds of I/O goes directly to/from a device to/from a memory location - that's DMA (Direct Memory Access) - If you are talking about DMA, then a good document to read is Documentation/DMA-API.txt Some kinds of I/O are buffered, like writes/reads to/from a harddrive. If that's what you are talking about, then reading Documentation/block/biodoc.txt is probably not a bad place to start reading. Documentation/IO-mapping.txt may also be of interrest to you. Hope that at least partially answered your question. -- Jesper Juhl <jesper.juhl@xxxxxxxxx> Don't top-post http://www.catb.org/~esr/jargon/html/T/top-post.html Plain text mails only, please http://www.expita.com/nomime.html -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
