virtio-mem: Offline and remove completely unplugged memory blocks (a5732387) · Commits · 戴 / test

drivers/virtio/virtio_mem.c

+43 −4

Original line number	Diff line number	Diff line
		@@ -446,6 +446,28 @@ static int virtio_mem_mb_remove(struct virtio_mem *vm, unsigned long mb_id)
		return remove_memory(nid, addr, memory_block_size_bytes());
		}

		/*
		* Try to offline and remove a memory block from Linux.
		*
		* Must not be called with the vm->hotplug_mutex held (possible deadlock with
		* onlining code).
		*
		* Will not modify the state of the memory block.
		*/
		static int virtio_mem_mb_offline_and_remove(struct virtio_mem *vm,
		unsigned long mb_id)
		{
		const uint64_t addr = virtio_mem_mb_id_to_phys(mb_id);
		int nid = vm->nid;

		if (nid == NUMA_NO_NODE)
		nid = memory_add_physaddr_to_nid(addr);

		dev_dbg(&vm->vdev->dev, "offlining and removing memory block: %lu\n",
		mb_id);
		return offline_and_remove_memory(nid, addr, memory_block_size_bytes());
		}

		/*
		* Trigger the workqueue so the device can perform its magic.
		*/
		@@ -537,7 +559,13 @@ static void virtio_mem_notify_offline(struct virtio_mem *vm,
		break;
		}

		/* trigger the workqueue, maybe we can now unplug memory. */
		/*
		* Trigger the workqueue, maybe we can now unplug memory. Also,
		* when we offline and remove a memory block, this will re-trigger
		* us immediately - which is often nice because the removal of
		* the memory block (e.g., memmap) might have freed up memory
		* on other memory blocks we manage.
		*/
		virtio_mem_retry(vm);
		}

		@@ -1284,7 +1312,8 @@ static int virtio_mem_mb_unplug_any_sb_offline(struct virtio_mem *vm,
		* Unplug the desired number of plugged subblocks of an online memory block.
		* Will skip subblock that are busy.
		*
		* Will modify the state of the memory block.
		* Will modify the state of the memory block. Might temporarily drop the
		* hotplug_mutex.
		*
		* Note: Can fail after some subblocks were successfully unplugged. Can
		* return 0 even if subblocks were busy and could not get unplugged.
		@@ -1340,9 +1369,19 @@ static int virtio_mem_mb_unplug_any_sb_online(struct virtio_mem *vm,
		}

		/*
		* TODO: Once all subblocks of a memory block were unplugged, we want
		* to offline the memory block and remove it.
		* Once all subblocks of a memory block were unplugged, offline and
		* remove it. This will usually not fail, as no memory is in use
		* anymore - however some other notifiers might NACK the request.
		*/
		if (virtio_mem_mb_test_sb_unplugged(vm, mb_id, 0, vm->nb_sb_per_mb)) {
		mutex_unlock(&vm->hotplug_mutex);
		rc = virtio_mem_mb_offline_and_remove(vm, mb_id);
		mutex_lock(&vm->hotplug_mutex);
		if (!rc)
		virtio_mem_mb_set_state(vm, mb_id,
		VIRTIO_MEM_MB_STATE_UNUSED);
		}

		return 0;
		}

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