Messages in this thread Patch in this message | | | Date | Tue, 22 Jul 2008 14:27:17 +0400 | From | Oleg Nesterov <> | Subject | [PATCH] workqueues: do CPU_UP_CANCELED if CPU_UP_PREPARE fails |
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(replaces workqueue-proper-error-unwinding-in-cpu-hotplug-error-path.patch)
The bug was pointed out by Akinobu Mita <akinobu.mita@gmail.com>, and this patch is based on his original patch.
workqueue_cpu_callback(CPU_UP_PREPARE) expects that if it returns NOTIFY_BAD, _cpu_up() will send CPU_UP_CANCELED then.
However, this is not true since
"cpu hotplug: cpu: deliver CPU_UP_CANCELED only to NOTIFY_OKed callbacks with CPU_UP_PREPARE" commit: a0d8cdb652d35af9319a9e0fb7134de2a276c636
The callback which has returned NOTIFY_BAD will not receive CPU_UP_CANCELED. Change the code to fulfil the CPU_UP_CANCELED logic if CPU_UP_PREPARE fails.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
--- 26-rc2/kernel/workqueue.c~WQ_CPU_UP_PREPARE 2008-07-12 19:40:57.000000000 +0400 +++ 26-rc2/kernel/workqueue.c 2008-07-22 13:43:47.000000000 +0400 @@ -911,6 +911,7 @@ static int __devinit workqueue_cpu_callb unsigned int cpu = (unsigned long)hcpu; struct cpu_workqueue_struct *cwq; struct workqueue_struct *wq; + int ret = NOTIFY_OK; action &= ~CPU_TASKS_FROZEN; @@ -918,7 +919,7 @@ static int __devinit workqueue_cpu_callb case CPU_UP_PREPARE: cpu_set(cpu, cpu_populated_map); } - +undo: list_for_each_entry(wq, &workqueues, list) { cwq = per_cpu_ptr(wq->cpu_wq, cpu); @@ -928,7 +929,9 @@ static int __devinit workqueue_cpu_callb break; printk(KERN_ERR "workqueue [%s] for %i failed\n", wq->name, cpu); - return NOTIFY_BAD; + action = CPU_UP_CANCELED; + ret = NOTIFY_BAD; + goto undo; case CPU_ONLINE: start_workqueue_thread(cwq, cpu); @@ -948,7 +951,7 @@ static int __devinit workqueue_cpu_callb cpu_clear(cpu, cpu_populated_map); } - return NOTIFY_OK; + return ret; } void __init init_workqueues(void)
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