virtio-mem: Unplug subblocks right-to-left

We unplug blocks right-to-left, let's also unplug subblocks within a block
right-to-left.

Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20200507140139.17083-14-david@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
David Hildenbrand 2020-05-07 16:01:37 +02:00 committed by Michael S. Tsirkin
parent 3c42e198e6
commit 562e08cd24

View File

@ -353,18 +353,6 @@ static bool virtio_mem_mb_test_sb_unplugged(struct virtio_mem *vm,
return find_next_bit(vm->sb_bitmap, bit + count, bit) >= bit + count;
}
/*
* Find the first plugged subblock. Returns vm->nb_sb_per_mb in case there is
* none.
*/
static int virtio_mem_mb_first_plugged_sb(struct virtio_mem *vm,
unsigned long mb_id)
{
const int bit = (mb_id - vm->first_mb_id) * vm->nb_sb_per_mb;
return find_next_bit(vm->sb_bitmap, bit + vm->nb_sb_per_mb, bit) - bit;
}
/*
* Find the first unplugged subblock. Returns vm->nb_sb_per_mb in case there is
* none.
@ -1016,21 +1004,27 @@ static int virtio_mem_mb_unplug_any_sb(struct virtio_mem *vm,
int sb_id, count;
int rc;
sb_id = vm->nb_sb_per_mb - 1;
while (*nb_sb) {
sb_id = virtio_mem_mb_first_plugged_sb(vm, mb_id);
if (sb_id >= vm->nb_sb_per_mb)
/* Find the next candidate subblock */
while (sb_id >= 0 &&
virtio_mem_mb_test_sb_unplugged(vm, mb_id, sb_id, 1))
sb_id--;
if (sb_id < 0)
break;
/* Try to unplug multiple subblocks at a time */
count = 1;
while (count < *nb_sb &&
sb_id + count < vm->nb_sb_per_mb &&
virtio_mem_mb_test_sb_plugged(vm, mb_id, sb_id + count,
1))
while (count < *nb_sb && sb_id > 0 &&
virtio_mem_mb_test_sb_plugged(vm, mb_id, sb_id - 1, 1)) {
count++;
sb_id--;
}
rc = virtio_mem_mb_unplug_sb(vm, mb_id, sb_id, count);
if (rc)
return rc;
*nb_sb -= count;
sb_id--;
}
return 0;
@ -1337,12 +1331,12 @@ static int virtio_mem_mb_unplug_any_sb_online(struct virtio_mem *vm,
* we should sense via something like is_mem_section_removable()
* first if it makes sense to go ahead any try to allocate.
*/
for (sb_id = 0; sb_id < vm->nb_sb_per_mb && *nb_sb; sb_id++) {
for (sb_id = vm->nb_sb_per_mb - 1; sb_id >= 0 && *nb_sb; sb_id--) {
/* Find the next candidate subblock */
while (sb_id < vm->nb_sb_per_mb &&
while (sb_id >= 0 &&
!virtio_mem_mb_test_sb_plugged(vm, mb_id, sb_id, 1))
sb_id++;
if (sb_id >= vm->nb_sb_per_mb)
sb_id--;
if (sb_id < 0)
break;
start_pfn = PFN_DOWN(virtio_mem_mb_id_to_phys(mb_id) +