Shameem Ahamed <[email protected]> writes: > Hi, > > Can anyone explain the difference between major and minor page faults. > > As far as I know, major page fault follows a disk access to retrieve > the data. Minor page fault occurs mainly for COW pages. Is there any > other instances other than COW, where there will be a minor page > fault. Which kernel function handles the major page fault ?.
Ignoring error cases, arch/x86/mm/fault.c:do_page_fault calls mm/memory.c:handle_mm_fault and looks for the flags, VM_FAULT_MAJOR or VM_FAULT_MINOR in the returned value, so the definitive answer is in how that return value gets set. The handle_mm_fault value comes from called function hugetlb_fault or handle_pte_fault (again, ignoring error conditions). I'd suggest starting your inquiry by looking at the logic in handle_pte_fault. > Also, can anyone please confirm that in 2.6 kernels, page cache and > buffer cache are normalized ?. Now we have only one cache, which > includes both buffer cache and page cache. They were last I heard. Things move so fast these days that I can't keep up! :) -- Ed Cashin <[email protected]> Find experimental aoe Linux driver patches at http://coraid.typepad.com/aoe_linux_proving_grounds/ -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to [email protected] Please read the FAQ at http://kernelnewbies.org/FAQ
