Messages in this thread |  | | Date | Fri, 31 May 1996 11:01:36 -0700 | From | "Leonard N. Zubkoff" <> | Subject | Re: Memory in Kernel space |
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From: Paul Gortmaker <gpg109@rsphy6.anu.edu.au> Date: Fri, 31 May 1996 17:02:55 +1000 (EST)
- From Balaji Srinivasan (balaji@eecs.ukans.edu) Thu, 30 May 1996 14:00:36 -0600 (CDT)
> I am modifying the kernel to do something that requires huge amounts of > memory in the kernel space. I allocate this memory in 4K blocks. > How much memory can I actually allocate in the kernel space as compared > to the RAM that I have (I have a 32 MB RAM and I need to allocate 25MB > or so)
Wow. If you need that much, then you are better off not letting the kernel have it in the first place. Simply boot with "mem=7m" and you can meddle with the upper 25MB as you see fit. The kernel won't touch it, and you don't need to futz about with kmalloc().
I don't think it's quite that simple. I tried this once, and if I recall correctly, the memory above the mem= value won't be mapped at all and the kernel will fault trying to access it. There probably is a way, but it's more complicated than this.
I think the easiest approach would be to add another call of the form:
memory_start = whatever_init(memory_start,memory_end);
into linux/init/main.c and let whatever_init ask for whatever it wants to reserve.
Leonard
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