From: Menglong Dong <imagedong@tencent.com> stable inclusion from stable-5.10.80 commit 5736f1dead8484cadf0843d5d9707ae1173f31e1 bugzilla: 185821 https://gitee.com/openeuler/kernel/issues/I4L7CG Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit d25302e46592c97d29f70ccb1be558df31a9a360 ] Some unfriendly component, such as dpdk, write the same mask to unbound kworker cpumask again and again. Every time it write to this interface some work is queue to cpu, even though the mask is same with the original mask. So, fix it by return success and do nothing if the cpumask is equal with the old one. Signed-off-by: Mengen Sun <mengensun@tencent.com> Signed-off-by: Menglong Dong <imagedong@tencent.com> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Chen Jun <chenjun102@huawei.com> Reviewed-by: Weilong Chen <chenweilong@huawei.com> Acked-by: Weilong Chen <chenweilong@huawei.com> Signed-off-by: Chen Jun <chenjun102@huawei.com> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> --- kernel/workqueue.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 29a677697fd4..af95ef023e1a 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -5331,9 +5331,6 @@ int workqueue_set_unbound_cpumask(cpumask_var_t cpumask) int ret = -EINVAL; cpumask_var_t saved_cpumask; - if (!zalloc_cpumask_var(&saved_cpumask, GFP_KERNEL)) - return -ENOMEM; - /* * Not excluding isolated cpus on purpose. * If the user wishes to include them, we allow that. @@ -5341,6 +5338,15 @@ int workqueue_set_unbound_cpumask(cpumask_var_t cpumask) cpumask_and(cpumask, cpumask, cpu_possible_mask); if (!cpumask_empty(cpumask)) { apply_wqattrs_lock(); + if (cpumask_equal(cpumask, wq_unbound_cpumask)) { + ret = 0; + goto out_unlock; + } + + if (!zalloc_cpumask_var(&saved_cpumask, GFP_KERNEL)) { + ret = -ENOMEM; + goto out_unlock; + } /* save the old wq_unbound_cpumask. */ cpumask_copy(saved_cpumask, wq_unbound_cpumask); @@ -5353,10 +5359,11 @@ int workqueue_set_unbound_cpumask(cpumask_var_t cpumask) if (ret < 0) cpumask_copy(wq_unbound_cpumask, saved_cpumask); + free_cpumask_var(saved_cpumask); +out_unlock: apply_wqattrs_unlock(); } - free_cpumask_var(saved_cpumask); return ret; } -- 2.20.1