Messages in this thread | | | Date | Wed, 11 Oct 2023 16:37:49 +0800 | Subject | Re: [PATCH drivers/perf: hisi:] drivers/perf: hisi: fix NULL pointer issue when uninstall hns3 pmu driver | From | Jijie Shao <> |
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on 2023/10/10 17:32, Yicong Yang wrote: > Hi Jijie, > > On 2023/10/9 18:50, Jijie Shao wrote: >> From: Hao Chen <chenhao418@huawei.com> >> >> When uninstall hns3 pmu driver, it will call cpuhp_state_remove_instance() >> and then callback function hns3_pmu_offline_cpu() is called, it may cause >> NULL pointer call trace when other driver is installing or uninstalling >> concurrently. >> > More information about the calltrace you've met and how to reproduce this? > I'm not sure why other drivers are involved. > >> As John Garry's opinion, cpuhp_state_remove_instance() is used for shared >> interrupt, and using cpuhp_state_remove_instance_nocalls() is fine for PCIe >> or HNS3 pmu. >> > I'm a bit confused here. We need to update the using CPU and migrate the perf > context as well as the interrupt affinity in cpuhp::teardown() callback, so > it make sense to not call this on driver detachment. But I cannot figure > out why this is related to the shared interrupt, more details? > ok,I will send v2 to add more details. Thanks
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