The patch titled cgroups: remove rcu_read_lock() in cgroupstats_build() has been added to the -mm tree. Its filename is cgroups-remove-rcu_read_lock-in-cgroupstats_build.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find out what to do about this The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: cgroups: remove rcu_read_lock() in cgroupstats_build() From: Lai Jiangshan <laijs@xxxxxxxxxxxxxx> cgroup_iter_* do not need rcu_read_lock(). In cgroup_enable_task_cg_lists(), do_each_thread() and while_each_thread() are protected by RCU, it's OK, for write_lock(&css_set_lock) implies rcu_read_lock() in non-RT kernel. If we need explicit rcu_read_lock(), we should add rcu_read_lock() in cgroup_enable_task_cg_lists(), not cgroup_iter_*. Signed-off-by: Lai Jiangshan <laijs@xxxxxxxxxxxxxx> Acked-by: Paul Menage <menage@xxxxxxxxxx> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> Cc: Pavel Emelyanov <xemul@xxxxxxxxxx> Cc: Balbir Singh <balbir@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- kernel/cgroup.c | 2 -- 1 file changed, 2 deletions(-) diff -puN kernel/cgroup.c~cgroups-remove-rcu_read_lock-in-cgroupstats_build kernel/cgroup.c --- a/kernel/cgroup.c~cgroups-remove-rcu_read_lock-in-cgroupstats_build +++ a/kernel/cgroup.c @@ -2055,7 +2055,6 @@ int cgroupstats_build(struct cgroupstats ret = 0; cgrp = dentry->d_fsdata; - rcu_read_lock(); cgroup_iter_start(cgrp, &it); while ((tsk = cgroup_iter_next(cgrp, &it))) { @@ -2080,7 +2079,6 @@ int cgroupstats_build(struct cgroupstats } cgroup_iter_end(cgrp, &it); - rcu_read_unlock(); err: return ret; } _ Patches currently in -mm which might be from laijs@xxxxxxxxxxxxxx are linux-next.patch kprobes-bugfix-try_module_get-even-if-calling_mod-is-null.patch cgroups-add-lock-for-child-cgroups-in-cgroup_post_fork.patch cgroups-fix-cgroup_iter_next-bug.patch cgroups-dont-put-struct-cgroupfs_root-protected-by-rcu.patch cgroups-use-task_lock-for-access-tsk-cgroups-safe-in-cgroup_clone.patch cgroups-call-find_css_set-safely-in-cgroup_attach_task.patch cgroups-remove-rcu_read_lock-in-cgroupstats_build.patch devcgroup-use-list_for_each_entry_rcu.patch memcontrol-rcu_read_lock-to-protect-mm_match_cgroup.patch cpuset-rcu_read_lock-to-protect-task_cs.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html