Messages in this thread | | | Date | Wed, 13 Dec 2017 08:06:17 -0800 | From | Tejun Heo <> | Subject | Re: [PATCH] cgroup/cpuset: fix circular locking dependency |
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Hello, Prateek.
On Wed, Dec 13, 2017 at 01:20:46PM +0530, Prateek Sood wrote: > This change makes the usage of cpuset_hotplug_workfn() from cpu > hotplug path synchronous. For memory hotplug it still remains > asynchronous.
Ah, right.
> Memory migration happening from cpuset_hotplug_workfn() is > already asynchronous by queuing cpuset_migrate_mm_workfn() in > cpuset_migrate_mm_wq. > > cpuset_hotplug_workfn() > cpuset_hotplug_workfn(() > cpuset_migrate_mm() > queue_work(cpuset_migrate_mm_wq) > > It seems that memory migration latency might not have > impact with this change. > > Please let me know if you meant something else by cpuset > migration taking time when memory migration is turned on.
No, I didn't. I was just confused about which part became synchronous. So, I don't have anything against making the cpu part synchronous, but let's not do that as the fix to the deadlocks cuz, while we can avoid them by changing cpuset, I don't think cpuset is the root cause for them. If there are benefits to making cpuset cpu migration synchronous, let's do that for those benefits.
Thanks.
-- tejun
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