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b=hBJkmeHoo3adk3zkUC7eYlw8h/TJyFQC7PnBfhei3eMbML+nMpxFUdoab8vEGHrC8 qv1TOSO6hpNr8vp5zd2I50DVcVBN2gbGEAaCVwtfnjCLuQaAOdZeOlXR/p7+Z4JKeP 9TN2uOi8STQr/J/OHftEHtUR0UvWj+6PFSAan524lD3d6akZQ7EehNCueclrUrGHOR 8ejbl/+TwuNme7llFf+Fy/j3D1/HZyvT3e7tKvC0GorCTf0v4LFtXuURtE7JiUbqv4 nlEE6828TnKP1RT6mAXgU/uOPKyk9IkmccHdH3cVzbR9hDg5I7E6j9AKneb4a6l/SN 0ymItKMeX+E/w== Date: Mon, 7 Sep 2026 13:27:03 +0100 From: "Lorenzo Stoakes (ARM)" To: Ye Liu Cc: Tony Luck , Reinette Chatre , x86@kernel.org, Christian Brauner , Andrew Morton , Jann Horn , "Mike Rapoport (Microsoft)" , "David Hildenbrand (arm)" , Alexey Dobriyan , Oleg Nesterov , Ye Liu , Michal Hocko , peterz@infradead.org, paulmck@kernel.org, mingo@redhat.com, rostedt@goodmis.org, jpoimboe@kernel.org, mic@digikod.net, tglx@kernel.org, linmiaohe@huawei.com, nao.horiguchi@gmail.com, rafael@kernel.org, gnoack3000@gmail.com, sj@kernel.org, rientjes@google.com, shakeel.butt@linux.dev, xu.xin16@zte.com.cn, chengming.zhou@linux.dev, will@kernel.org, boqun@kernel.org, frederic@kernel.org, neeraj.upadhyay@kernel.org, joelagnelf@nvidia.com, josh@joshtriplett.org, urezki@gmail.com, juri.lelli@redhat.com, vincent.guittot@linaro.org, paul@paul-moore.com, jmorris@namei.org, serge@hallyn.com, pavel@kernel.org, lance.yang@linux.dev, mhiramat@kernel.org, pmladek@suse.com, longman@redhat.com, mathieu.desnoyers@efficios.com, jiangshanlai@gmail.com, qiang.zhang@linux.dev, dietmar.eggemann@arm.com, bsegall@google.com, mgorman@suse.de, vschneid@redhat.com, kprateek.nayak@amd.com, mark.rutland@arm.com, Dave.Martin@arm.com, james.morse@arm.com, babu.moger@amd.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, rcu@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-security-module@vger.kernel.org Subject: Re: [PATCH v2 6/8] fs: convert process/thread iterators to for_each_*_rculock Message-ID: References: <20260907081334.1152889-1-ye.liu@linux.dev> <20260907081334.1152889-7-ye.liu@linux.dev> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260907081334.1152889-7-ye.liu@linux.dev> X-Stat-Signature: ca5e6o8jhyh1bza9efb5npbgpqmti3un X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: BD1084000E X-Rspam-User: X-HE-Tag: 1788784040-305889 X-HE-Meta: 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 jozuZXyB UcqJ+aXSgVjYawmvdVP41SeSr3sOcPHeD6N7L6NclLEW6QizeXGObkCDdLfPAkgg7tXrail1yMVogDj4lTqUkpTROt8DjW2yDfcDD28W5XQ/uSfrL4FuIUbsGXkHiORrn+1zru8QhFGWbAA52RgYW6xO+9XoVJxUP7oD7NgtJbbvZFAcglqIxidwmk5JWs/nDYsQY0pQMSJ4TNDZIhkMwoa8oSqNLmNnz+akB/WKOWSO7kyU9zi2bV7ow/vX1fZUR7ibfPgtdt4dUHX/2U3qco32OdlAbYltx2xvZuJQw9sTZ4sFX+6pLhPlf3gWH5Ln0WYIbAgScZ7dOnrABQ9CRJr3gW/7qIsHS/ukh2lFbDbqZKDh8YU7k7wd8vcuN76slNBDPdRb4moQdvLErEXvseWwI5vuH5BmQo6UgYxcObfKOt4DMIXl6X+rd8XMP+Vczcq0PAaBl0oRJZqw= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Mon, Sep 07, 2026 at 04:13:32PM +0800, Ye Liu wrote: > From: Ye Liu > > Replace the manual rcu_read_lock()/rcu_read_unlock() pairs combined > with for_each_process() and for_each_process_thread() loops in fs/ > with the for_each_*_rculock() macros, which scope the RCU read lock > to the loop body via scoped_guard(rcu). > > No functional change. > > Signed-off-by: Ye Liu > Acked-by: Michal Hocko LGTM so: Reviewed-by: Lorenzo Stoakes (ARM) > --- > Changes in v2: > - Rename *_rcu to *_rculock > fs/proc/base.c | 4 +--- > fs/resctrl/rdtgroup.c | 8 ++------ > 2 files changed, 3 insertions(+), 9 deletions(-) > > diff --git a/fs/proc/base.c b/fs/proc/base.c > index 6a39de424f62..3de4f4557e4c 100644 > --- a/fs/proc/base.c > +++ b/fs/proc/base.c > @@ -1160,8 +1160,7 @@ static int __set_oom_adj(struct file *file, int oom_adj, bool legacy) > if (mm) { > struct task_struct *p; > > - rcu_read_lock(); > - for_each_process(p) { > + for_each_process_rculock(p) { > if (same_thread_group(task, p)) > continue; > > @@ -1177,7 +1176,6 @@ static int __set_oom_adj(struct file *file, int oom_adj, bool legacy) > } > task_unlock(p); > } > - rcu_read_unlock(); > mmdrop(mm); > } > err_unlock: > diff --git a/fs/resctrl/rdtgroup.c b/fs/resctrl/rdtgroup.c > index 5dcbb0a964e8..b14df8b23f1a 100644 > --- a/fs/resctrl/rdtgroup.c > +++ b/fs/resctrl/rdtgroup.c > @@ -709,14 +709,12 @@ int rdtgroup_tasks_assigned(struct rdtgroup *r) > > lockdep_assert_held(&rdtgroup_mutex); > > - rcu_read_lock(); > - for_each_process_thread(p, t) { > + for_each_process_thread_rculock(p, t) { > if (is_closid_match(t, r) || is_rmid_match(t, r)) { > ret = 1; > break; > } > } > - rcu_read_unlock(); > > return ret; > } > @@ -826,15 +824,13 @@ static void show_rdt_tasks(struct rdtgroup *r, struct seq_file *s) > struct task_struct *p, *t; > pid_t pid; > > - rcu_read_lock(); > - for_each_process_thread(p, t) { > + for_each_process_thread_rculock(p, t) { > if (is_closid_match(t, r) || is_rmid_match(t, r)) { > pid = task_pid_vnr(t); > if (pid) > seq_printf(s, "%d\n", pid); > } > } > - rcu_read_unlock(); > } > > static int rdtgroup_tasks_show(struct kernfs_open_file *of, > -- > 2.25.1 > -- Cheers, Lorenzo