using ioremap over kernel memory boot time reservation -

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firstly have admit i'm newbie. don't go hard on me plz. want reserve memory @ boot time , use memory in kernel module in order sure module 1 using space . m going : add mem= , , memmap= kerenl parameters reserve memory @ boot time . questions begin here :

  1. if use ioremap on space in module code accessible in other modules ? or other kernel subsystems cant still see it?
  2. second question : how can sure reserved memory never move swap space ?
  3. third 1 : how can access memory block devices ? mean /dev/sda or ..... .

(1) using ioremap, you're establishing kernel virtual address memory. other code in kernel space can access sticking right value pointer variable. afaik, there's no way of "locking" area of memory single kernel module. parts of kernel all-powerful , hence can access memory -- or @ least, can operations might required allow them access memory like. same token, there no reason piece of kernel code going access memory unless cause somehow. after all, you've told rest of kernel it's not normal memory.

(2) excluding memory kernel memory map, using ioremap you're in effect telling kernel it's kind of special "i/o" memory (think pci device's i/o memory region, example), , hence wouldn't considered paging reason.

i don't know of way can achieve goal in (3) without implementing own device interface memory. however, if that's want use for, why not create ramdisk filesystem? no (additional) kernel programming required that. (see documentation/blockdev/ramdisk.txt in kernel source tree.)


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