From: Frederic Weisbecker Date: Wed, 28 May 2025 16:19:23 +0000 (+0200) Subject: cpuset: Propagate cpuset isolation update to workqueue through housekeeping X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=23f09dcc0a0fa3b4e48516bdea1c90223dfb3d6c;p=thirdparty%2Flinux.git cpuset: Propagate cpuset isolation update to workqueue through housekeeping Until now, cpuset would propagate isolated partition changes to workqueues so that unbound workers get properly reaffined. Since housekeeping now centralizes, synchronize and propagates isolation cpumask changes, perform the work from that subsystem for consolidation and consistency purposes. For simplification purpose, the target function is adapted to take the new housekeeping mask instead of the isolated mask. Suggested-by: Tejun Heo Signed-off-by: Frederic Weisbecker Reviewed-by: Waiman Long Acked-by: Tejun Heo Cc: "Michal Koutný" Cc: Ingo Molnar Cc: Johannes Weiner Cc: Lai Jiangshan Cc: Marco Crivellari Cc: Michal Hocko Cc: Peter Zijlstra Cc: Tejun Heo Cc: Thomas Gleixner Cc: Vlastimil Babka Cc: Waiman Long Cc: cgroups@vger.kernel.org --- diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h index dabc351cc127d..a4749f56398fd 100644 --- a/include/linux/workqueue.h +++ b/include/linux/workqueue.h @@ -588,7 +588,7 @@ struct workqueue_attrs *alloc_workqueue_attrs_noprof(void); void free_workqueue_attrs(struct workqueue_attrs *attrs); int apply_workqueue_attrs(struct workqueue_struct *wq, const struct workqueue_attrs *attrs); -extern int workqueue_unbound_exclude_cpumask(cpumask_var_t cpumask); +extern int workqueue_unbound_housekeeping_update(const struct cpumask *hk); extern bool queue_work_on(int cpu, struct workqueue_struct *wq, struct work_struct *work); diff --git a/init/Kconfig b/init/Kconfig index fa79feb8fe57b..518830fb812f3 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1254,6 +1254,7 @@ config CPUSETS bool "Cpuset controller" depends on SMP select UNION_FIND + select CPU_ISOLATION help This option will let you create and manage CPUSETs which allow dynamically partitioning a system into sets of CPUs and diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c index e146e1f34bf97..6309ec5d7b2a1 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -1482,15 +1482,12 @@ static void update_isolation_cpumasks(void) if (!isolated_cpus_updating) return; - ret = workqueue_unbound_exclude_cpumask(isolated_cpus); + ret = housekeeping_update(isolated_cpus); WARN_ON_ONCE(ret < 0); ret = tmigr_isolated_exclude_cpumask(isolated_cpus); WARN_ON_ONCE(ret < 0); - ret = housekeeping_update(isolated_cpus); - WARN_ON_ONCE(ret < 0); - isolated_cpus_updating = false; } diff --git a/kernel/sched/isolation.c b/kernel/sched/isolation.c index 1e4c3154b0a4c..5bcb6d760f20b 100644 --- a/kernel/sched/isolation.c +++ b/kernel/sched/isolation.c @@ -121,6 +121,7 @@ EXPORT_SYMBOL_GPL(housekeeping_test_cpu); int housekeeping_update(struct cpumask *isol_mask) { struct cpumask *trial, *old = NULL; + int err; lockdep_assert_cpus_held(); @@ -148,6 +149,8 @@ int housekeeping_update(struct cpumask *isol_mask) pci_probe_flush_workqueue(); mem_cgroup_flush_workqueue(); vmstat_flush_workqueue(); + err = workqueue_unbound_housekeeping_update(housekeeping_cpumask(HK_TYPE_DOMAIN)); + WARN_ON_ONCE(err < 0); kfree(old); diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 253311af47c6d..eb56600132220 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -6959,13 +6959,16 @@ static int workqueue_apply_unbound_cpumask(const cpumask_var_t unbound_cpumask) } /** - * workqueue_unbound_exclude_cpumask - Exclude given CPUs from unbound cpumask - * @exclude_cpumask: the cpumask to be excluded from wq_unbound_cpumask + * workqueue_unbound_housekeeping_update - Propagate housekeeping cpumask update + * @hk: the new housekeeping cpumask * - * This function can be called from cpuset code to provide a set of isolated - * CPUs that should be excluded from wq_unbound_cpumask. + * Update the unbound workqueue cpumask on top of the new housekeeping cpumask such + * that the effective unbound affinity is the intersection of the new housekeeping + * with the requested affinity set via nohz_full=/isolcpus= or sysfs. + * + * Return: 0 on success and -errno on failure. */ -int workqueue_unbound_exclude_cpumask(cpumask_var_t exclude_cpumask) +int workqueue_unbound_housekeeping_update(const struct cpumask *hk) { cpumask_var_t cpumask; int ret = 0; @@ -6981,14 +6984,14 @@ int workqueue_unbound_exclude_cpumask(cpumask_var_t exclude_cpumask) * (HK_TYPE_WQ ∩ HK_TYPE_DOMAIN) house keeping mask and rewritten * by any subsequent write to workqueue/cpumask sysfs file. */ - if (!cpumask_andnot(cpumask, wq_requested_unbound_cpumask, exclude_cpumask)) + if (!cpumask_and(cpumask, wq_requested_unbound_cpumask, hk)) cpumask_copy(cpumask, wq_requested_unbound_cpumask); if (!cpumask_equal(cpumask, wq_unbound_cpumask)) ret = workqueue_apply_unbound_cpumask(cpumask); /* Save the current isolated cpumask & export it via sysfs */ if (!ret) - cpumask_copy(wq_isolated_cpumask, exclude_cpumask); + cpumask_andnot(wq_isolated_cpumask, cpu_possible_mask, hk); mutex_unlock(&wq_pool_mutex); free_cpumask_var(cpumask);