Messages in this thread | | | Date | Tue, 15 Sep 2015 17:26:22 -0400 | From | Tejun Heo <> | Subject | Re: [4.2] commit d59cfc09c32 (sched, cgroup: replace signal_struct->group_rwsem with a global percpu_rwsem) causes regression for libvirt/kvm |
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Hello,
On Tue, Sep 15, 2015 at 11:11:45PM +0200, Christian Borntraeger wrote: > > In fact, I would say that any userspace-controlled call to *_expedited() > > is a bug waiting to happen and a bad idea---because userspace can, with > > little effort, end up calling it in a loop. > > Right. This also implies that we should fix this for 4.2 - I guess.
Are the percpu_rwsem changes enough? If so, we can try to backport those. If those are too risky, we can revert the patches which switched threadgroup lock to percpu_rwsem.
Thanks.
-- tejun
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