Re: [PATCH 2/2] S390 topology: don't use kthread() forarch_reinit_sched_domains()

From: Heiko Carstens
Date: Mon Jun 30 2008 - 09:45:51 EST


On Sun, Jun 29, 2008 at 08:51:32PM +0400, Oleg Nesterov wrote:
> Untested, needs Heiko's ack.
>
> Now that it is safe to use get_online_cpus() we can revert
>
> [S390] cpu topology: Fix possible deadlock.
> commit: fd781fa25c9e9c6fd1599df060b05e7c4ad724e5
>
> and call arch_reinit_sched_domains() directly from topology_work_fn().
>
> Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
>
> --- 26-rc2/arch/s390/kernel/topology.c~WQ_5_TOPOLOGY 2008-05-18 15:43:28.000000000 +0400
> +++ 26-rc2/arch/s390/kernel/topology.c 2008-06-29 20:42:38.000000000 +0400
> @@ -9,7 +9,6 @@
> #include <linux/device.h>
> #include <linux/bootmem.h>
> #include <linux/sched.h>
> -#include <linux/kthread.h>
> #include <linux/workqueue.h>
> #include <linux/cpu.h>
> #include <linux/smp.h>
> @@ -230,20 +229,9 @@ void arch_update_cpu_topology(void)
> }
> }
>
> -static int topology_kthread(void *data)
> -{
> - arch_reinit_sched_domains();
> - return 0;
> -}
> -
> static void topology_work_fn(struct work_struct *work)
> {
> - /* We can't call arch_reinit_sched_domains() from a multi-threaded
> - * workqueue context since it may deadlock in case of cpu hotplug.
> - * So we have to create a kernel thread in order to call
> - * arch_reinit_sched_domains().
> - */
> - kthread_run(topology_kthread, NULL, "topology_update");
> + arch_reinit_sched_domains();

Thank you! Tested and still works ;)

Acked-by: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
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