The patch titled Subject: memcg: let css_get_next() rely upon rcu_read_lock() has been removed from the -mm tree. Its filename was memcg-let-css_get_next-rely-upon-rcu_read_lock.patch This patch was dropped because it was merged into mainline or a subsystem tree The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ From: Hugh Dickins <hughd@xxxxxxxxxx> Subject: memcg: let css_get_next() rely upon rcu_read_lock() Remove lock and unlock around css_get_next()'s call to idr_get_next(). memcg iterators (only users of css_get_next) already did rcu_read_lock(), and its comment demands that; but add a WARN_ON_ONCE to make sure of it. Signed-off-by: Hugh Dickins <hughd@xxxxxxxxxx> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> Acked-by: Li Zefan <lizf@xxxxxxxxxxxxxx> Cc: Eric Dumazet <eric.dumazet@xxxxxxxxx> Acked-by: Tejun Heo <tj@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- kernel/cgroup.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff -puN kernel/cgroup.c~memcg-let-css_get_next-rely-upon-rcu_read_lock kernel/cgroup.c --- a/kernel/cgroup.c~memcg-let-css_get_next-rely-upon-rcu_read_lock +++ a/kernel/cgroup.c @@ -5033,6 +5033,8 @@ css_get_next(struct cgroup_subsys *ss, i return NULL; BUG_ON(!ss->use_id); + WARN_ON_ONCE(!rcu_read_lock_held()); + /* fill start point for scan */ tmpid = id; while (1) { @@ -5040,10 +5042,7 @@ css_get_next(struct cgroup_subsys *ss, i * scan next entry from bitmap(tree), tmpid is updated after * idr_get_next(). */ - spin_lock(&ss->id_lock); tmp = idr_get_next(&ss->idr, &tmpid); - spin_unlock(&ss->id_lock); - if (!tmp) break; if (tmp->depth >= depth && tmp->stack[depth] == rootid) { _ Patches currently in -mm which might be from hughd@xxxxxxxxxx are origin.patch linux-next.patch mm-hugetlb-cleanup-duplicated-code-in-unmapping-vm-range.patch radix-tree-introduce-bit-optimized-iterator.patch radix-tree-introduce-bit-optimized-iterator-v3.patch radix-tree-introduce-bit-optimized-iterator-v3-fix.patch radix-tree-rewrite-gang-lookup-with-using-iterator.patch radix-tree-use-iterators-in-find_get_pages-functions.patch prio_tree-debugging-patch.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