Messages in this thread | | | Date | Sun, 06 Apr 2003 15:25:08 -0700 | From | "Martin J. Bligh" <> | Subject | Re: subobj-rmap |
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>> We can always leave the sys_remap_file_pages stuff using pte_chains, > > not sure why you want still to have the vm to know about the > mmap(VM_NONLINEAR) hack at all. > > that's a vm bypass. I can bet the people who wants to use it for running > faster on the the 32bit archs will definitely prefer zero overhead and > full hardware speed with only the pagetable and tlb flushing trash, and > zero additional kernel internal overhead. that's just a vm bypass that > could otherwise sit in kernel module, not a real kernel API.
Well, you don't get zero overhead whatever you do. You either pay the cost at remap time of manipulating sub-objects, or the cost at page-touch time of the pte_chains stuff. I suspect sub-objects are cheaper if we read /write the 32K chunks, not if people mostly just touch one page per remap though.
What do you think about using this for the linear stuff though?
M.
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