Messages in this thread | | | Date | Wed, 29 Mar 2023 22:43:38 +0500 | Subject | Re: [PATCH 6.0.y / 6.1.y] x86/split_lock: Add sysctl to control the misery mode | From | stsp <> |
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Hi Sean, thanks for a head-up!
29.03.2023 22:14, Sean Christopherson пишет: > Resurrecting this thread with a concrete use case. > dosemu2, which uses KVM to accelerate DOS emulation (stating the obvious), ran > into a problem where the hardcoded (prior to this patch) behavior will effectively > hang userspace if the 10ms sleep is interrupted, e.g. by a periodic SIGALRM[*].
Yes, and we also created a ready-to-use host test-case with no dosemu2 involved.
> Alternatively, we could try to figure out a way to ensure forward progress without > letting userpace run an end-around on the enforced misery, but backporting this > patch to stable kernels seems easier. > > Stas, do you happen to know what the oldest stable kernel your users use, i.e. > how far back this backport would need to go? It seems, the "broken" code was added by the patch b041b525dab95 which is "described" as v5.18-rc4-1-gb041b525dab9. So I guess the answer would be "down to 5.18".
Of course I don't believe the patch you mention, is a real solution. Its good for -stable, but something else needs to be developed in the future.
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