Messages in this thread |  | | From | "Christophe Beaumont" <> | Subject | HUGE contiguous mem space with 2.4 | Date | Mon, 21 May 2001 15:39:32 -0700 |
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Hi...
I am facing an odd problem here. I have an application here that requires a HUGE physically contiguous memory area to be locked (yes, I have hardware DMA'ing in and out of that area, over the PCI bus). HUGE being like one Gig (could be more if needed...) I am trying to use the mem=1024M option at boot time (yes, the box has 2 Gigs of RAM) and then ioremap() from within my module. There I have a couple of issues: - if I use high_memory as is, I cannot remap any area (high_memory=f800:0000 ???) - if I use high_memory thru virt_to_phys, I can then remap... up to 64 Megs (maybe a little more, but for sure less than 128 Megs) (virt_to_phys(high_mem)=3800:0000)
I tried with other values (like mem=250M 512M 1536M) and could NOT remap anything close to the whole amount of "reserved" memory (best case being with mem=256M I can remap 512M out of 1.75Gigs)
I guess I am missing a point somewhere.... or have totally been "ignoring" some doc somewhere (alessandro could be the man for this one thing *-) )
[system is a dual P3 with 2 gigs of RAM, a 2.4.3 kernel with SMP turned on... and the nice option for 4Gigs of RAM... would the 64Gig option help me??? just wondering there...]
Any pointer, advise, help, hint... laugh at the stupid thing I have forgotten is more than welcome..
tia
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