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charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-OriginatorOrg: microsoft.com X-MS-Exchange-CrossTenant-Network-Message-Id: 7ac148ec-95be-4a88-9d27-08d76997dcd7 X-MS-Exchange-CrossTenant-originalarrivaltime: 15 Nov 2019 06:48:45.7673 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 72f988bf-86f1-41af-91ab-2d7cd011db47 X-MS-Exchange-CrossTenant-mailboxtype: HOSTED X-MS-Exchange-CrossTenant-userprincipalname: 2BCLbe+mNHdMUZUjn+8FunJ1lcguqmFTxOOtyPVd/kcXOv1QF6u6YpyASMylvuR+NJFGPJEyPtU7wBBQ05lsMA== X-MS-Exchange-Transport-CrossTenantHeadersStamped: PU1P153MB0169 Sender: linux-hyperv-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-hyperv@vger.kernel.org > From: Michael Kelley > Sent: Tuesday, November 12, 2019 5:12 PM > ... > @@ -190,14 +278,20 @@ void hv_stimer_free(void) > void hv_stimer_global_cleanup(void) > { > int cpu; > ... > + /* > + * hv_stime_legacy_cleanup() will stop the stimer if Direct > + * Mode is not enabled, and fallback to the LAPIC timer. > + */ > + for_each_present_cpu(cpu) { > + hv_stimer_legacy_cleanup(cpu); > } > + > + /* > + * If Direct Mode is enabled, the cpuhp teardown callback > + * (hv_stimer_cleanup) will be run on all CPUs to stop the > + * stimers. > + */ > hv_stimer_free(); > } In the case of direct_mode_enabled =3D=3D true: When hv_vmbus unloads, vmbus_exit() -> hv_stimer_global_cleanup() -> hv_stimer_free() -> cpuhp_remove_state() disables the direct mode timers. This does not look symmetric since hv_stimer_alloc() is called before hv_vmbus loads, but I suppose this is not a real issue because hv_vmbus should never unload in practice. :-) Tested-by: Dexuan Cui Reviewed-by: Dexuan Cui