Kernel Study Notes

0.0.1. summarypage_to_pfn and pfn_to_page are often used in kernel. for PP81, kernel uses CONFIG_DISCONTIGMEM + NUMA.Every node has node_mem_map and node_start_pfnto help the page/pfn covertion.n

0.0.1. summaryThere is a list xfrm_km_list in kernel.Each node of the list is struct xfrm_mgr,which has several methods to notify usersapce by netlink message.Different methods has corresponding metho

In order to understand kernel route LC-Trie,summary the basic functions here.

0.1. kprobe is a useful tool when debug kernel.It can directly hook the related function of kernel,before or after it run. It also can be used to patch kernel in some special case.

0.1. usage:In version management, we often meet this case: 123When a line/file is deleted for git repo?or who did it ? In this case, we need git bisect. git bisect start git bisect good commit_id1 gi

0.1. Q: Does kernel IPv6 route support route cache ? yes. but it is very different with IPv4. It should be ‘clone’ strictly speaking. For simple let us only focus on ip6_pol_route, and variable st

0.1. summaryIP4 route register a call back notify in IPv4 address.When a address is added, fib_inetaddr_event will be called. and then 4 route entry maybe added in fib_add_ifaddr

0.1. SUMMARYThere is a struct in_device __rcu *ip_ptr under every net_device.which stores all the IPv4 related information for this device. Each IPv4 address is stored a struct in_ifaddr,all the IPv4

unregister_netdev is used to delete a net device. In fact, it equals: 1234rtnl_lock();rollback_registered_many( a temp list with a single net device);list_add_tail(&dev->todo_list, &net_tod

0.1. summaryThere is a struct rt_rq in struct rq. struct rt_rq is used to store allthe realtime task in current struct rq. which has a struct rt_prio_array active.