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-rw-r--r--drivers/virtio/virtio_mem.c88
1 files changed, 57 insertions, 31 deletions
diff --git a/drivers/virtio/virtio_mem.c b/drivers/virtio/virtio_mem.c
index abd93b778a26..9e523db3bee1 100644
--- a/drivers/virtio/virtio_mem.c
+++ b/drivers/virtio/virtio_mem.c
@@ -1308,6 +1308,46 @@ static int virtio_mem_mb_unplug_any_sb_offline(struct virtio_mem *vm,
}
/*
+ * Unplug the given plugged subblocks of an online memory block.
+ *
+ * Will modify the state of the memory block.
+ */
+static int virtio_mem_mb_unplug_sb_online(struct virtio_mem *vm,
+ unsigned long mb_id, int sb_id,
+ int count)
+{
+ const unsigned long nr_pages = PFN_DOWN(vm->subblock_size) * count;
+ unsigned long start_pfn;
+ int rc;
+
+ start_pfn = PFN_DOWN(virtio_mem_mb_id_to_phys(mb_id) +
+ sb_id * vm->subblock_size);
+ rc = alloc_contig_range(start_pfn, start_pfn + nr_pages,
+ MIGRATE_MOVABLE, GFP_KERNEL);
+ if (rc == -ENOMEM)
+ /* whoops, out of memory */
+ return rc;
+ if (rc)
+ return -EBUSY;
+
+ /* Mark it as fake-offline before unplugging it */
+ virtio_mem_set_fake_offline(start_pfn, nr_pages, true);
+ adjust_managed_page_count(pfn_to_page(start_pfn), -nr_pages);
+
+ /* Try to unplug the allocated memory */
+ rc = virtio_mem_mb_unplug_sb(vm, mb_id, sb_id, count);
+ if (rc) {
+ /* Return the memory to the buddy. */
+ virtio_mem_fake_online(start_pfn, nr_pages);
+ return rc;
+ }
+
+ virtio_mem_mb_set_state(vm, mb_id,
+ VIRTIO_MEM_MB_STATE_ONLINE_PARTIAL);
+ return 0;
+}
+
+/*
* Unplug the desired number of plugged subblocks of an online memory block.
* Will skip subblock that are busy.
*
@@ -1321,16 +1361,21 @@ static int virtio_mem_mb_unplug_any_sb_online(struct virtio_mem *vm,
unsigned long mb_id,
uint64_t *nb_sb)
{
- const unsigned long nr_pages = PFN_DOWN(vm->subblock_size);
- unsigned long start_pfn;
int rc, sb_id;
- /*
- * TODO: To increase the performance we want to try bigger, consecutive
- * subblocks first before falling back to single subblocks. Also,
- * we should sense via something like is_mem_section_removable()
- * first if it makes sense to go ahead any try to allocate.
- */
+ /* If possible, try to unplug the complete block in one shot. */
+ if (*nb_sb >= vm->nb_sb_per_mb &&
+ virtio_mem_mb_test_sb_plugged(vm, mb_id, 0, vm->nb_sb_per_mb)) {
+ rc = virtio_mem_mb_unplug_sb_online(vm, mb_id, 0,
+ vm->nb_sb_per_mb);
+ if (!rc) {
+ *nb_sb -= vm->nb_sb_per_mb;
+ goto unplugged;
+ } else if (rc != -EBUSY)
+ return rc;
+ }
+
+ /* Fallback to single subblocks. */
for (sb_id = vm->nb_sb_per_mb - 1; sb_id >= 0 && *nb_sb; sb_id--) {
/* Find the next candidate subblock */
while (sb_id >= 0 &&
@@ -1339,34 +1384,15 @@ static int virtio_mem_mb_unplug_any_sb_online(struct virtio_mem *vm,
if (sb_id < 0)
break;
- start_pfn = PFN_DOWN(virtio_mem_mb_id_to_phys(mb_id) +
- sb_id * vm->subblock_size);
- rc = alloc_contig_range(start_pfn, start_pfn + nr_pages,
- MIGRATE_MOVABLE, GFP_KERNEL);
- if (rc == -ENOMEM)
- /* whoops, out of memory */
- return rc;
- if (rc)
- /* memory busy, we can't unplug this chunk */
+ rc = virtio_mem_mb_unplug_sb_online(vm, mb_id, sb_id, 1);
+ if (rc == -EBUSY)
continue;
-
- /* Mark it as fake-offline before unplugging it */
- virtio_mem_set_fake_offline(start_pfn, nr_pages, true);
- adjust_managed_page_count(pfn_to_page(start_pfn), -nr_pages);
-
- /* Try to unplug the allocated memory */
- rc = virtio_mem_mb_unplug_sb(vm, mb_id, sb_id, 1);
- if (rc) {
- /* Return the memory to the buddy. */
- virtio_mem_fake_online(start_pfn, nr_pages);
+ else if (rc)
return rc;
- }
-
- virtio_mem_mb_set_state(vm, mb_id,
- VIRTIO_MEM_MB_STATE_ONLINE_PARTIAL);
*nb_sb -= 1;
}
+unplugged:
/*
* Once all subblocks of a memory block were unplugged, offline and
* remove it. This will usually not fail, as no memory is in use