Messages in this thread | | | From | Lai Jiangshan <> | Date | Thu, 22 Jul 2021 10:05:45 +0800 | Subject | Re: [PATCH] workqueue: Fix possible memory leaks in wq_numa_init() |
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Please ignore my previous email which included/copied a wrong line of code.
On Thu, Jul 22, 2021 at 12:23 AM Tejun Heo <tj@kernel.org> wrote: > Yeah, idk. It's not an actual bug tho. Maybe we should just add a comment. > Which version do you like the best?
I hope Zhen Lei continues to refine his version. I think he is still working on it.
On Mon, Jul 19, 2021 at 3:00 PM Zhen Lei <thunder.leizhen@huawei.com> wrote: > > In error handling branch "if (WARN_ON(node == NUMA_NO_NODE))", the > previously allocated memories are not released. Doing this before > allocating memory eliminates memory leaks. > > Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> > --- > kernel/workqueue.c | 19 ++++++++++--------- > 1 file changed, 10 insertions(+), 9 deletions(-) > > diff --git a/kernel/workqueue.c b/kernel/workqueue.c > index 50142fc08902..6aa0ba582d15 100644 > --- a/kernel/workqueue.c > +++ b/kernel/workqueue.c > @@ -5896,6 +5896,14 @@ static void __init wq_numa_init(void) > return; > } > > + for_each_possible_cpu(cpu) { > + if (WARN_ON(cpu_to_node(cpu) == NUMA_NO_NODE)) { > + pr_warn("workqueue: NUMA node mapping not available for cpu%d, disabling NUMA support\n", cpu);
> + /* happens iff arch is bonkers, let's just proceed */
I don't think this comment is still needed.
> + return; > + } > + } > + > wq_update_unbound_numa_attrs_buf = alloc_workqueue_attrs(); > BUG_ON(!wq_update_unbound_numa_attrs_buf); > > @@ -5907,18 +5915,11 @@ static void __init wq_numa_init(void) > tbl = kcalloc(nr_node_ids, sizeof(tbl[0]), GFP_KERNEL); > BUG_ON(!tbl); > > - for_each_node(node) > + for_each_node(node) { > BUG_ON(!zalloc_cpumask_var_node(&tbl[node], GFP_KERNEL, > node_online(node) ? node : NUMA_NO_NODE)); > > - for_each_possible_cpu(cpu) { > - node = cpu_to_node(cpu); > - if (WARN_ON(node == NUMA_NO_NODE)) { > - pr_warn("workqueue: NUMA node mapping not available for cpu%d, disabling NUMA support\n", cpu); > - /* happens iff arch is bonkers, let's just proceed */ > - return; > - } > - cpumask_set_cpu(cpu, tbl[node]); > + cpumask_copy(tbl[node], cpumask_of_node(node));
It is incorrect. cpumask_of_node(node) is the online cpumask of the node, not the possible cpumask of the node that we are interested in.
If the NUMA subsystem provided something like cpumask_possible_of_node(node), we wouldn't need wq_numa_possible_cpumask.
Please keep "for_each_possible_cpu(cpu)" loop and "cpumask_set_cpu(cpu, tbl[node]);"
> } > > wq_numa_possible_cpumask = tbl; > -- > 2.25.1 >
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