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b=dt1YvAUg6NQDSEDvgG9mbQNggE1DpbwJYzMW4bcdlZql+uP+sMxqkUWIYAXsCyIq5 coopp1kNdFyVaxSNXMEYuqQdamxoZARBxr6/t2IIpNcq7WwRE/IdJAYLPCVwlAJaWH tA5XXCdJgaMjyMpblDZk2E8jRfJIlW4C3XdTPPmivDkJqXxdgp1VDXYfAUR4AvdZ/g HNsX23T6/YieZlixieteuyT8T5FyobPtxs21tLst44lvW5pzaO1hrglEyJ5O9AFNG8 q/mvBXkYa3rmnye/abn6dOoOlhqDPg3K7lRJlgZIbKtr/PzWNIFK6M9D4REDm265Pf ALtpygYtu6h/Q== Date: Mon, 7 Sep 2026 09:36:07 +0100 From: "Lorenzo Stoakes (ARM)" To: Ye Liu Cc: Andrew Morton , David Hildenbrand , Ye Liu , Michal Hocko , SJ Park , peterz@infradead.org, paulmck@kernel.org, mingo@redhat.com, rostedt@goodmis.org, jpoimboe@kernel.org, mic@digikod.net, oleg@redhat.com, tglx@kernel.org, linmiaohe@huawei.com, nao.horiguchi@gmail.com, rafael@kernel.org, gnoack3000@gmail.com, 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, tony.luck@intel.com, reinette.chatre@intel.com, x86@kernel.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 3/8] mm/ksm: convert process iterator to for_each_process_rculock Message-ID: References: <20260907081334.1152889-1-ye.liu@linux.dev> <20260907081334.1152889-4-ye.liu@linux.dev> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260907081334.1152889-4-ye.liu@linux.dev> X-Rspamd-Server: rspam11 X-Rspam-User: X-Stat-Signature: f36bwnukndnnib1h94g8x33uz7feu6mf X-Rspamd-Queue-Id: DB43F160002 X-HE-Tag: 1788770183-38217 X-HE-Meta: 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 84sz3FbS oGTP+SdBPG9iAiVg/WLxwWbj4hibgG8F+OamQp8o43VYwJm4ZPLnyxUwaQxaCVMOGFWQwgheDr9qz6AkiJxE9Ld4x5+GVe5swUyOYihzJcUau6ElHoI8HIDw9/KPwFeY6KFxklnjesmbXBy9268hZ6eHobErzUItCmE9GPT6LoZXOXXsz+pRwuzuSTnBSynlcuRC2znChtmFa3/CtDmj51QSfkUI5Y7BeUzGsqOcV8oZX1D9NzdwcK0jTH6uKUbivv7IX/tCFqcQNG4Cbgq3GIJtf1vnhj/nm2XN2z++9Uy/UCT9lvPUf/pMCt5JsvcI3Liw1ih1WjjxnqCLTSfNbP0Jyg4ytD/a3+yjwFyfkSdCZQ9hoBrVy4WFoJtJ9aIRrS9A1iyLApMNc8vSYUBPIns6pky5aQYF64xOD6EbYmrg7wbO9ypc1wMQ8MMcHuSL0i0fRlLXuwwyJQc8= 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 04:13:29PM +0800, Ye Liu wrote: > From: Ye Liu > > Replace the manual rcu_read_lock()/rcu_read_unlock() pair combined > with for_each_process() loop in mm/ksm.c with for_each_process_rculock(), > which scopes the RCU read lock to the loop body via scoped_guard(rcu). > > No functional change. > > Signed-off-by: Ye Liu > Acked-by: Michal Hocko > Reviewed-by: SJ Park LGTM so: Reviewed-by: Lorenzo Stoakes (ARM) > --- > Changes in v2: > - Rename *_rcu to *_rculock > mm/ksm.c | 4 +--- > 1 file changed, 1 insertion(+), 3 deletions(-) > > diff --git a/mm/ksm.c b/mm/ksm.c > index 49d48d1e0998..69d30e80a090 100644 > --- a/mm/ksm.c > +++ b/mm/ksm.c > @@ -3280,8 +3280,7 @@ void collect_procs_ksm(const struct folio *folio, const struct page *page, > struct anon_vma *av = rmap_item->anon_vma; > > anon_vma_lock_read(av); > - rcu_read_lock(); > - for_each_process(tsk) { > + for_each_process_rculock(tsk) { > struct anon_vma_chain *vmac; > const unsigned long addr = rmap_item->address & PAGE_MASK; > const unsigned long index = rmap_item->linear_page_index; > @@ -3298,7 +3297,6 @@ void collect_procs_ksm(const struct folio *folio, const struct page *page, > } > } > } > - rcu_read_unlock(); > anon_vma_unlock_read(av); > } > } > -- > 2.25.1 > -- Cheers, Lorenzo