Messages in this thread | | | Subject | Re: [4.2] commit d59cfc09c32 (sched, cgroup: replace signal_struct->group_rwsem with a global percpu_rwsem) causes regression for libvirt/kvm | From | Christian Borntraeger <> | Date | Wed, 16 Sep 2015 10:57:40 +0200 |
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Am 16.09.2015 um 10:32 schrieb Paolo Bonzini: > > > On 15/09/2015 19:38, Paul E. McKenney wrote: >> Excellent points! >> >> Other options in such situations include the following: >> >> o Rework so that the code uses call_rcu*() instead of *_expedited(). >> >> o Maintain a per-task or per-CPU counter so that every so many >> *_expedited() invocations instead uses the non-expedited >> counterpart. (For example, synchronize_rcu instead of >> synchronize_rcu_expedited().) > > Or just use ratelimit (untested):
One of my tests was to always replace synchronize_sched_expedited with synchronize_sched and things turned out to be even worse. Not sure if it makes sense to test yopur in-the-middle approach?
Christian
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