From: David Hildenbrand <david@redhat.com>
To: linux-kernel@vger.kernel.org
Cc: linux-mm@kvack.org, virtualization@lists.linux-foundation.org,
Andrea Arcangeli <aarcange@redhat.com>,
David Hildenbrand <david@redhat.com>,
"Michael S. Tsirkin" <mst@redhat.com>,
Jason Wang <jasowang@redhat.com>,
Oscar Salvador <osalvador@suse.de>,
Michal Hocko <mhocko@kernel.org>,
Igor Mammedov <imammedo@redhat.com>,
Dave Young <dyoung@redhat.com>,
Andrew Morton <akpm@linux-foundation.org>,
Dan Williams <dan.j.williams@intel.com>,
Pavel Tatashin <pasha.tatashin@soleen.com>,
Stefan Hajnoczi <stefanha@redhat.com>,
Vlastimil Babka <vbabka@suse.cz>
Subject: [PATCH RFC v3 9/9] virtio-mem: Offline and remove completely unplugged memory blocks
Date: Thu, 19 Sep 2019 16:22:28 +0200 [thread overview]
Message-ID: <20190919142228.5483-10-david@redhat.com> (raw)
In-Reply-To: <20190919142228.5483-1-david@redhat.com>
Let's offline+remove memory blocks once all subblocks are unplugged. We
can use the new Linux MM interface for that. As no memory is in use
anymore, this shouldn't take a long time and shouldn't fail. There might
be corner cases where the offlining could still fail (especially, if
another notifier NACKs the offlining request).
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
drivers/virtio/virtio_mem.c | 39 ++++++++++++++++++++++++++++++++++---
1 file changed, 36 insertions(+), 3 deletions(-)
diff --git a/drivers/virtio/virtio_mem.c b/drivers/virtio/virtio_mem.c
index 9cb31459b211..01d5fc784d5d 100644
--- a/drivers/virtio/virtio_mem.c
+++ b/drivers/virtio/virtio_mem.c
@@ -433,6 +433,28 @@ 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.
*/
@@ -1263,7 +1285,8 @@ 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.
@@ -1319,9 +1342,19 @@ 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;
}
--
2.21.0
next prev parent reply other threads:[~2019-09-19 14:23 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-19 14:22 [PATCH RFC v3 0/9] virtio-mem: paravirtualized memory David Hildenbrand
2019-09-19 14:22 ` [PATCH RFC v3 1/9] ACPI: NUMA: export pxm_to_node David Hildenbrand
2019-09-23 10:13 ` David Hildenbrand
2019-09-23 10:36 ` Michal Hocko
2019-09-23 10:39 ` David Hildenbrand
2019-09-19 14:22 ` [PATCH RFC v3 2/9] virtio-mem: Paravirtualized memory hotplug David Hildenbrand
2019-09-19 14:22 ` [PATCH RFC v3 3/9] virtio-mem: Paravirtualized memory hotunplug part 1 David Hildenbrand
2019-09-19 14:22 ` [PATCH RFC v3 4/9] mm: Export alloc_contig_range() / free_contig_range() David Hildenbrand
2019-10-16 11:20 ` Michal Hocko
2019-10-16 12:31 ` David Hildenbrand
2019-09-19 14:22 ` [PATCH RFC v3 5/9] virtio-mem: Paravirtualized memory hotunplug part 2 David Hildenbrand
2019-09-19 14:22 ` [PATCH RFC v3 6/9] mm: Allow to offline PageOffline() pages with a reference count of 0 David Hildenbrand
2019-10-16 11:43 ` Michal Hocko
2019-10-16 12:50 ` David Hildenbrand
2019-10-16 13:45 ` Michal Hocko
2019-10-16 13:55 ` David Hildenbrand
2019-10-16 14:09 ` Michal Hocko
2019-10-16 14:16 ` David Hildenbrand
2019-10-16 13:59 ` David Hildenbrand
2019-10-16 13:45 ` David Hildenbrand
2019-10-16 14:03 ` Michal Hocko
2019-10-16 14:14 ` David Hildenbrand
2019-10-18 8:15 ` Michal Hocko
2019-10-18 8:50 ` David Hildenbrand
2019-10-18 11:20 ` Michal Hocko
2019-10-18 12:35 ` David Hildenbrand
2019-10-22 12:23 ` Michal Hocko
2019-10-22 14:02 ` David Hildenbrand
2019-10-23 9:43 ` Michal Hocko
2019-10-23 10:03 ` David Hildenbrand
2019-10-24 8:42 ` Michal Hocko
2019-10-24 8:51 ` David Hildenbrand
2019-10-25 11:28 ` [PATCH RFC] mm: Allow to offline unmovable PageOffline() pages if the driver agrees David Hildenbrand
2019-09-19 14:22 ` [PATCH RFC v3 7/9] virtio-mem: Allow to offline partially unplugged memory blocks David Hildenbrand
2019-09-19 14:22 ` [PATCH RFC v3 8/9] mm/memory_hotplug: Introduce offline_and_remove_memory() David Hildenbrand
2019-10-16 11:47 ` Michal Hocko
2019-10-16 12:57 ` David Hildenbrand
2019-09-19 14:22 ` David Hildenbrand [this message]
2019-10-16 8:12 ` [PATCH RFC v3 0/9] virtio-mem: paravirtualized memory David Hildenbrand
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