kernel/include/net/cls_cgroup.h, branch linux-4.1.y

cgroup: clean up cgroup_subsys names and initialization

2014-02-08T15:36:58Z

cgroup_subsys is a bit messier than it needs to be. * The name of a subsys can be different from its internal identifier defined in cgroup_subsys.h. Most subsystems use the matching name but three - cpu, memory and perf_event - use different ones. * cgroup_subsys_id enums are postfixed with _subsys_id and each cgroup_subsys is postfixed with _subsys. cgroup.h is widely included throughout various subsystems, it doesn't and shouldn't have claim on such generic names which don't have any qualifier indicating that they belong to cgroup. * cgroup_subsys->subsys_id should always equal the matching cgroup_subsys_id enum; however, we require each controller to initialize it and then BUG if they don't match, which is a bit silly. This patch cleans up cgroup_subsys names and initialization by doing the followings. * cgroup_subsys_id enums are now postfixed with _cgrp_id, and each cgroup_subsys with _cgrp_subsys. * With the above, renaming subsys identifiers to match the userland visible names doesn't cause any naming conflicts. All non-matching identifiers are renamed to match the official names. cpu_cgroup -> cpu mem_cgroup -> memory perf -> perf_event * controllers no longer need to initialize ->subsys_id and ->name. They're generated in cgroup core and set automatically during boot. * Redundant cgroup_subsys declarations removed. * While updating BUG_ON()s in cgroup_init_early(), convert them to WARN()s. BUGging that early during boot is stupid - the kernel can't print anything, even through serial console and the trap handler doesn't even link stack frame properly for back-tracing. This patch doesn't introduce any behavior changes. v2: Rebased on top of fe1217c4f3f7 ("net: net_cls: move cgroupfs classid handling into core"). Signed-off-by: Tejun Heo Acked-by: Neil Horman Acked-by: "David S. Miller" Acked-by: "Rafael J. Wysocki" Acked-by: Michal Hocko Acked-by: Peter Zijlstra Acked-by: Aristeu Rozanski Acked-by: Ingo Molnar Acked-by: Li Zefan Cc: Johannes Weiner Cc: Balbir Singh Cc: KAMEZAWA Hiroyuki Cc: Serge E. Hallyn Cc: Vivek Goyal Cc: Thomas Graf

net: net_cls: move cgroupfs classid handling into core

2014-01-03T22:41:41Z

Zefan Li requested [1] to perform the following cleanup/refactoring: - Split cgroupfs classid handling into net core to better express a possible more generic use. - Disable module support for cgroupfs bits as the majority of other cgroupfs subsystems do not have that, and seems to be not wished from cgroup side. Zefan probably might want to follow-up for netprio later on. - By this, code can be further reduced which previously took care of functionality built when compiled as module. cgroupfs bits are being placed under net/core/netclassid_cgroup.c, so that we are consistent with {netclassid,netprio}_cgroup naming that is under net/core/ as suggested by Zefan. No change in functionality, but only code refactoring that is being done here. [1] http://patchwork.ozlabs.org/patch/304825/ Suggested-by: Li Zefan Signed-off-by: Daniel Borkmann Cc: Zefan Li Cc: Thomas Graf Cc: cgroups@vger.kernel.org Acked-by: Li Zefan Signed-off-by: Pablo Neira Ayuso

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next

2013-09-05T21:54:29Z

Pull networking changes from David Miller: "Noteworthy changes this time around: 1) Multicast rejoin support for team driver, from Jiri Pirko. 2) Centralize and simplify TCP RTT measurement handling in order to reduce the impact of bad RTO seeding from SYN/ACKs. Also, when both timestamps and local RTT measurements are available prefer the later because there are broken middleware devices which scramble the timestamp. From Yuchung Cheng. 3) Add TCP_NOTSENT_LOWAT socket option to limit the amount of kernel memory consumed to queue up unsend user data. From Eric Dumazet. 4) Add a "physical port ID" abstraction for network devices, from Jiri Pirko. 5) Add a "suppress" operation to influence fib_rules lookups, from Stefan Tomanek. 6) Add a networking development FAQ, from Paul Gortmaker. 7) Extend the information provided by tcp_probe and add ipv6 support, from Daniel Borkmann. 8) Use RCU locking more extensively in openvswitch data paths, from Pravin B Shelar. 9) Add SCTP support to openvswitch, from Joe Stringer. 10) Add EF10 chip support to SFC driver, from Ben Hutchings. 11) Add new SYNPROXY netfilter target, from Patrick McHardy. 12) Compute a rate approximation for sending in TCP sockets, and use this to more intelligently coalesce TSO frames. Furthermore, add a new packet scheduler which takes advantage of this estimate when available. From Eric Dumazet. 13) Allow AF_PACKET fanouts with random selection, from Daniel Borkmann. 14) Add ipv6 support to vxlan driver, from Cong Wang" Resolved conflicts as per discussion. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1218 commits) openvswitch: Fix alignment of struct sw_flow_key. netfilter: Fix build errors with xt_socket.c tcp: Add missing braces to do_tcp_setsockopt caif: Add missing braces to multiline if in cfctrl_linkup_request bnx2x: Add missing braces in bnx2x:bnx2x_link_initialize vxlan: Fix kernel panic on device delete. net: mvneta: implement ->ndo_do_ioctl() to support PHY ioctls net: mvneta: properly disable HW PHY polling and ensure adjust_link() works icplus: Use netif_running to determine device state ethernet/arc/arc_emac: Fix huge delays in large file copies tuntap: orphan frags before trying to set tx timestamp tuntap: purge socket error queue on detach qlcnic: use standard NAPI weights ipv6:introduce function to find route for redirect bnx2x: VF RSS support - VF side bnx2x: VF RSS support - PF side vxlan: Notify drivers for listening UDP port changes net: usbnet: update addr_assign_type if appropriate driver/net: enic: update enic maintainers and driver driver/net: enic: Exposing symbols for Cisco's low latency driver ...

cgroup: s/cgroup_subsys_state/cgroup_css/ s/task_subsys_state/task_css/

2013-08-09T00:11:22Z

The names of the two struct cgroup_subsys_state accessors - cgroup_subsys_state() and task_subsys_state() - are somewhat awkward. The former clashes with the type name and the latter doesn't even indicate it's somehow related to cgroup. We're about to revamp large portion of cgroup API, so, let's rename them so that they're less awkward. Most per-controller usages of the accessors are localized in accessor wrappers and given the amount of scheduled changes, this isn't gonna add any noticeable headache. Rename cgroup_subsys_state() to cgroup_css() and task_subsys_state() to task_css(). This patch is pure rename. Signed-off-by: Tejun Heo Acked-by: Li Zefan

cls_cgroup.h netprio_cgroup.h: Remove extern from function prototypes

2013-08-01T00:50:02Z

There are a mix of function prototypes with and without extern in the kernel sources. Standardize on not using extern for function prototypes. Function prototypes don't need to be written with extern. extern is assumed by the compiler. Its use is as unnecessary as using auto to declare automatic/local variables in a block. Signed-off-by: Joe Perches Signed-off-by: David S. Miller

cls_cgroup: remove task_struct parameter from sock_update_classid()

2013-04-09T17:19:35Z

The callers always pass current to sock_update_classid(). Signed-off-by: Li Zefan Acked-by: Neil Horman Signed-off-by: David S. Miller

net: Update args to dummy sock_update_classid().

2012-10-26T09:07:00Z

Only the real implementation got updated. Signed-off-by: David S. Miller

cgroup: net_cls: Pass in task to sock_update_classid()

2012-10-26T07:40:50Z

sock_update_classid() assumes that the update operation always are applied on the current task. sock_update_classid() needs to know on which tasks to work on in order to be able to migrate task between cgroups using the struct cgroup_subsys attach() callback. Signed-off-by: Daniel Wagner Cc: "David S. Miller" Cc: "Michael S. Tsirkin" Cc: Eric Dumazet Cc: Glauber Costa Cc: Joe Perches Cc: Neil Horman Cc: Stanislav Kinsbursky Cc: Tejun Heo Cc: Cc: Acked-by: Neil Horman Signed-off-by: David S. Miller

cgroup: net_cls: Fix local variable type decleration

2012-10-26T07:40:50Z

The classid type used throughout the kernel is u32. Signed-off-by: Daniel Wagner Cc: "David S. Miller" Cc: Li Zefan Cc: Tejun Heo Cc: Cc: Acked-by: Neil Horman Signed-off-by: David S. Miller

cgroup: Assign subsystem IDs during compile time

2012-09-14T16:57:43Z

WARNING: With this change it is impossible to load external built controllers anymore. In case where CONFIG_NETPRIO_CGROUP=m and CONFIG_NET_CLS_CGROUP=m is set, corresponding subsys_id should also be a constant. Up to now, net_prio_subsys_id and net_cls_subsys_id would be of the type int and the value would be assigned during runtime. By switching the macro definition IS_SUBSYS_ENABLED from IS_BUILTIN to IS_ENABLED, all *_subsys_id will have constant value. That means we need to remove all the code which assumes a value can be assigned to net_prio_subsys_id and net_cls_subsys_id. A close look is necessary on the RCU part which was introduces by following patch: commit f845172531fb7410c7fb7780b1a6e51ee6df7d52 Author: Herbert Xu Mon May 24 09:12:34 2010 Committer: David S. Miller Mon May 24 09:12:34 2010 cls_cgroup: Store classid in struct sock Tis code was added to init_cgroup_cls() /* We can't use rcu_assign_pointer because this is an int. */ smp_wmb(); net_cls_subsys_id = net_cls_subsys.subsys_id; respectively to exit_cgroup_cls() net_cls_subsys_id = -1; synchronize_rcu(); and in module version of task_cls_classid() rcu_read_lock(); id = rcu_dereference(net_cls_subsys_id); if (id >= 0) classid = container_of(task_subsys_state(p, id), struct cgroup_cls_state, css)->classid; rcu_read_unlock(); Without an explicit explaination why the RCU part is needed. (The rcu_deference was fixed by exchanging it to rcu_derefence_index_check() in a later commit, but that is a minor detail.) So here is my pondering why it was introduced and why it safe to remove it now. Note that this code was copied over to net_prio the reasoning holds for that subsystem too. The idea behind the RCU use for net_cls_subsys_id is to make sure we get a valid pointer back from task_subsys_state(). task_subsys_state() is just blindly accessing the subsys array and returning the pointer. Obviously, passing in -1 as id into task_subsys_state() returns an invalid value (out of lower bound). So this code makes sure that only after module is loaded and the subsystem registered, the id is assigned. Before unregistering the module all old readers must have left the critical section. This is done by assigning -1 to the id and issuing a synchronized_rcu(). Any new readers wont call task_subsys_state() anymore and therefore it is safe to unregister the subsystem. The new code relies on the same trick, but it looks at the subsys pointer return by task_subsys_state() (remember the id is constant and therefore we allways have a valid index into the subsys array). No precautions need to be taken during module loading module. Eventually, all CPUs will get a valid pointer back from task_subsys_state() because rebind_subsystem() which is called after the module init() function will assigned subsys[net_cls_subsys_id] the newly loaded module subsystem pointer. When the subsystem is about to be removed, rebind_subsystem() will called before the module exit() function. In this case, rebind_subsys() will assign subsys[net_cls_subsys_id] a NULL pointer and then it calls synchronize_rcu(). All old readers have left by then the critical section. Any new reader wont access the subsystem anymore. At this point we are safe to unregister the subsystem. No synchronize_rcu() call is needed. Signed-off-by: Daniel Wagner Signed-off-by: Tejun Heo Acked-by: Li Zefan Acked-by: Neil Horman Cc: "David S. Miller" Cc: "Paul E. McKenney" Cc: Andrew Morton Cc: Eric Dumazet Cc: Gao feng Cc: Glauber Costa Cc: Herbert Xu Cc: Jamal Hadi Salim Cc: John Fastabend Cc: Kamezawa Hiroyuki Cc: netdev@vger.kernel.org Cc: cgroups@vger.kernel.org