Hi, This is marked as a v3 as it started as a result of discussions that followed the v2 [1].
The idea with this series is to add CPU hotunplug timeout to avoid the situations where the kernel refuses to release the CPU. The reasoning for a timeout approach is described in patch 05. While investigating putting a timeout in memory hotunplug, I have found out that we have a way to determine, at least in some cases, when the kernel refuses to release the DIMM during a memory hotunplug. This alleviate one of the most common issues (at least AFAIK) with memory hotunplug and it made me gave up attempting to put a timeout in memory hotunplug altogether. At this point I didn't add timeouts for PCI hotunplug operations, but it is trivial to do so if desirable. The series goes as follows: - Patches 1-4: DRC simplifications/cleanups. The idea with these cleanups were to trim the spapr_drc_detach use as much as possible, since the function would be used to start the timeout timer - Patch 5: timeout timer infrastructure - Patch 6: add cpu unplug timeout - Patch 7: reset DIMM unplug state when the kernel reconfigures the DRC connector v2 link: [1] https://lists.gnu.org/archive/html/qemu-devel/2021-01/msg04400.html Daniel Henrique Barboza (7): spapr_drc.c: do not call spapr_drc_detach() in drc_isolate_logical() spapr_pci.c: simplify spapr_pci_unplug_request() function handling spapr_drc.c: use spapr_drc_release() in isolate_physical/set_unusable spapr: rename spapr_drc_detach() to spapr_drc_unplug_request() spapr_drc.c: introduce unplug_timeout_timer spapr_drc.c: add hotunplug timeout for CPUs spapr_drc.c: use DRC reconfiguration to cleanup DIMM unplug state hw/ppc/spapr.c | 40 ++++++++++++- hw/ppc/spapr_drc.c | 116 +++++++++++++++++++++++++++---------- hw/ppc/spapr_pci.c | 44 +++++--------- hw/ppc/trace-events | 2 +- include/hw/ppc/spapr.h | 2 + include/hw/ppc/spapr_drc.h | 7 ++- 6 files changed, 147 insertions(+), 64 deletions(-) -- 2.29.2
