Merge "workqueue: Affine rescuer threads and unbound wqs"

kernel-rt/centos/kernel-rt.spec

@@ -787,6 +787,7 @@ Patch7: 0008-Allow-dmar-quirks-for-broken-bioses.patch
 Patch8: 0009-tpm-ignore-burstcount-to-improve-tpm_tis-send-perfor.patch
 Patch9: 0010-restrict-iSCSI-kthreads-to-CPUs-in-cpu_kthread_mask.patch
 Patch10: 0011-scsi-smartpqi-Enable-sas_address-sysfs-for-SATA-dev.patch
+Patch11: 0012-workqueue-Affine-rescuer-threads-and-unbound-wqs.patch
 
 # END OF PATCH DEFINITIONS
 %endif

kernel-rt/centos/patches/0012-workqueue-Affine-rescuer-threads-and-unbound-wqs.patch

@@ -0,0 +1,55 @@
+From 9c5c44019a17897c46a2579a50abcd69f1bcb4a8 Mon Sep 17 00:00:00 2001
+From: "M. Vefa Bicakci" <vefa.bicakci@windriver.com>
+Date: Thu, 9 Sep 2021 04:56:46 -0400
+Subject: [PATCH] workqueue: Affine rescuer threads and unbound wqs
+
+This commit ensures that workqueue rescuer threads are affined to the
+platform CPUs specified by the "kthread_cpus" kernel argument. Prior to
+this commit, rescuer threads could be bound to any CPU. Rescuer threads
+are described in "kernel/workqueue.c" as follows:
+
+"Regular work processing on a pool may block trying to create a new
+worker which uses GFP_KERNEL allocation which has slight chance of
+developing into deadlock if some works currently on the same queue
+need to be processed to satisfy the GFP_KERNEL allocation.  This is
+the problem rescuer solves.
+
+When such condition is possible, the pool summons rescuers of all
+workqueues which have works queued on the pool and let them process
+those works so that forward progress can be guaranteed."
+
+This commit also affines unbound workqueues to the platform CPUs instead
+of the housekeeping CPUs, because the latter can be a superset of the
+former.
+
+Signed-off-by: M. Vefa Bicakci <vefa.bicakci@windriver.com>
+Signed-off-by: Jiping Ma <jiping.ma2@windriver.com>
+---
+ kernel/workqueue.c | 4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+diff --git a/kernel/workqueue.c b/kernel/workqueue.c
+index 1e2ca744dadb..f208096f28f1 100644
+--- a/kernel/workqueue.c
++++ b/kernel/workqueue.c
+@@ -4235,7 +4235,7 @@ static int init_rescuer(struct workqueue_struct *wq)
+ 	}
+ 
+ 	wq->rescuer = rescuer;
+-	kthread_bind_mask(rescuer->task, cpu_possible_mask);
++	kthread_bind_mask(rescuer->task, cpu_kthread_mask);
+ 	wake_up_process(rescuer->task);
+ 
+ 	return 0;
+@@ -5927,7 +5927,7 @@ void __init workqueue_init_early(void)
+ 	BUILD_BUG_ON(__alignof__(struct pool_workqueue) < __alignof__(long long));
+ 
+ 	BUG_ON(!alloc_cpumask_var(&wq_unbound_cpumask, GFP_KERNEL));
+-	cpumask_copy(wq_unbound_cpumask, housekeeping_cpumask(hk_flags));
++	cpumask_copy(wq_unbound_cpumask, cpu_kthread_mask);
+ 
+ 	pwq_cache = KMEM_CACHE(pool_workqueue, SLAB_PANIC);
+ 
+-- 
+2.29.2
+

kernel-std/centos/kernel.spec

@@ -820,6 +820,7 @@ Patch7: 0008-Allow-dmar-quirks-for-broken-bioses.patch
 Patch8: 0009-tpm-ignore-burstcount-to-improve-tpm_tis-send-perfor.patch
 Patch9: 0010-bpf-cgroups-Fix-cgroup-v2-fallback-on-v1-v2-mixed-mo.patch
 Patch10: 0011-scsi-smartpqi-Enable-sas_address-sysfs-for-SATA-dev.patch
+Patch11: 0012-workqueue-Affine-rescuer-threads-and-unbound-wqs.patch
 
 # END OF PATCH DEFINITIONS
 %endif

kernel-std/centos/patches/0012-workqueue-Affine-rescuer-threads-and-unbound-wqs.patch

@@ -0,0 +1,55 @@
+From 9c5c44019a17897c46a2579a50abcd69f1bcb4a8 Mon Sep 17 00:00:00 2001
+From: "M. Vefa Bicakci" <vefa.bicakci@windriver.com>
+Date: Thu, 9 Sep 2021 04:56:46 -0400
+Subject: [PATCH] workqueue: Affine rescuer threads and unbound wqs
+
+This commit ensures that workqueue rescuer threads are affined to the
+platform CPUs specified by the "kthread_cpus" kernel argument. Prior to
+this commit, rescuer threads could be bound to any CPU. Rescuer threads
+are described in "kernel/workqueue.c" as follows:
+
+"Regular work processing on a pool may block trying to create a new
+worker which uses GFP_KERNEL allocation which has slight chance of
+developing into deadlock if some works currently on the same queue
+need to be processed to satisfy the GFP_KERNEL allocation.  This is
+the problem rescuer solves.
+
+When such condition is possible, the pool summons rescuers of all
+workqueues which have works queued on the pool and let them process
+those works so that forward progress can be guaranteed."
+
+This commit also affines unbound workqueues to the platform CPUs instead
+of the housekeeping CPUs, because the latter can be a superset of the
+former.
+
+Signed-off-by: M. Vefa Bicakci <vefa.bicakci@windriver.com>
+Signed-off-by: Jiping Ma <jiping.ma2@windriver.com>
+---
+ kernel/workqueue.c | 4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+diff --git a/kernel/workqueue.c b/kernel/workqueue.c
+index 1e2ca744dadb..f208096f28f1 100644
+--- a/kernel/workqueue.c
++++ b/kernel/workqueue.c
+@@ -4235,7 +4235,7 @@ static int init_rescuer(struct workqueue_struct *wq)
+ 	}
+ 
+ 	wq->rescuer = rescuer;
+-	kthread_bind_mask(rescuer->task, cpu_possible_mask);
++	kthread_bind_mask(rescuer->task, cpu_kthread_mask);
+ 	wake_up_process(rescuer->task);
+ 
+ 	return 0;
+@@ -5927,7 +5927,7 @@ void __init workqueue_init_early(void)
+ 	BUILD_BUG_ON(__alignof__(struct pool_workqueue) < __alignof__(long long));
+ 
+ 	BUG_ON(!alloc_cpumask_var(&wq_unbound_cpumask, GFP_KERNEL));
+-	cpumask_copy(wq_unbound_cpumask, housekeeping_cpumask(hk_flags));
++	cpumask_copy(wq_unbound_cpumask, cpu_kthread_mask);
+ 
+ 	pwq_cache = KMEM_CACHE(pool_workqueue, SLAB_PANIC);
+ 
+-- 
+2.29.2
+