kernel/include/linux/cgroup-defs.h, branch linux-4.1.y

cgroup: use bitmask to filter for_each_subsys

2017-06-08T02:52:11Z

[ Upstream commit cb4a316752709be4a644f070440a8be470d92b7d ] Add a new macro for_each_subsys_which that allows all enabled cgroup subsystems to be filtered by a bitmask, such that mask & (1 << ssid) determines if the subsystem is to be processed in the loop body (where ssid is the unique id of the subsystem). Also replace the need_forkexit_callback with two separate bitmasks for each callback to make (ss->{fork,exit}) checks unnecessary. tj: add a short comment for "if (!CGROUP_SUBSYS_COUNT)". Signed-off-by: Aleksa Sarai Signed-off-by: Sasha Levin

sched, cgroup: reorganize threadgroup locking

2017-06-08T02:52:05Z

[ Upstream commit 7d7efec368d537226142cbe559f45797f18672f9 ] threadgroup_change_begin/end() are used to mark the beginning and end of threadgroup modifying operations to allow code paths which require a threadgroup to stay stable across blocking operations to synchronize against those sections using threadgroup_lock/unlock(). It's currently implemented as a general mechanism in sched.h using per-signal_struct rwsem; however, this never grew non-cgroup use cases and becomes noop if !CONFIG_CGROUPS. It turns out that cgroups is gonna be better served with a different sycnrhonization scheme and is a bit silly to keep cgroups specific details as a general mechanism. What's general here is identifying the places where threadgroups are modified. This patch restructures threadgroup locking so that threadgroup_change_begin/end() become a place where subsystems which need to sycnhronize against threadgroup changes can hook into. cgroup_threadgroup_change_begin/end() which operate on the per-signal_struct rwsem are created and threadgroup_lock/unlock() are moved to cgroup.c and made static. This is pure reorganization which doesn't cause any functional changes. Signed-off-by: Tejun Heo Cc: Ingo Molnar Cc: Peter Zijlstra Signed-off-by: Sasha Levin

cgroup: make sure a parent css isn't offlined before its children

2016-02-23T05:49:17Z

[ Upstream commit aa226ff4a1ce79f229c6b7a4c0a14e17fececd01 ] There are three subsystem callbacks in css shutdown path - css_offline(), css_released() and css_free(). Except for css_released(), cgroup core didn't guarantee the order of invocation. css_offline() or css_free() could be called on a parent css before its children. This behavior is unexpected and led to bugs in cpu and memory controller. This patch updates offline path so that a parent css is never offlined before its children. Each css keeps online_cnt which reaches zero iff itself and all its children are offline and offline_css() is invoked only after online_cnt reaches zero. This fixes the memory controller bug and allows the fix for cpu controller. Signed-off-by: Tejun Heo Reported-and-tested-by: Christian Borntraeger Reported-by: Brian Christiansen Link: http://lkml.kernel.org/g/5698A023.9070703@de.ibm.com Link: http://lkml.kernel.org/g/CAKB58ikDkzc8REt31WBkD99+hxNzjK4+FBmhkgS+NVrC9vjMSg@mail.gmail.com Cc: Heiko Carstens Cc: Peter Zijlstra Cc: stable@vger.kernel.org Signed-off-by: Sasha Levin

cgroup: separate out include/linux/cgroup-defs.h

2016-02-23T05:49:13Z

[ Upstream commit b4a04ab7a37b490cad48e69abfe14288cacb669c ] From 2d728f74bfc071df06773e2fd7577dd5dab6425d Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Wed, 13 May 2015 15:37:01 -0400 This patch separates out cgroup-defs.h from cgroup.h which has grown a lot of dependencies. cgroup-defs.h currently only contains constant and type definitions and can be used to break circular include dependency. While moving, definitions are reordered so that cgroup-defs.h has consistent logical structure. This patch is pure reorganization. Signed-off-by: Tejun Heo Signed-off-by: Sasha Levin