diff options
| author | Gavin Shan <gshan@redhat.com> | 2021-06-28 19:35:25 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-06-29 10:53:47 -0700 |
| commit | f8af4d0892cbb84fc3913de75ba5da374147a691 (patch) | |
| tree | 2e2be43635615c3e70649e774add5582d1f0620a /drivers/virtio | |
| parent | 9f849c6f9572d8cef407f55928d3dc68fc42ad3e (diff) | |
virtio_balloon: specify page reporting order if needed
The page reporting won't be triggered if the freeing page can't come up
with a free area, whose size is equal or bigger than the threshold (page
reporting order). The default page reporting order, equal to
@pageblock_order, is too huge on some architectures to trigger page
reporting. One example is ARM64 when 64KB base page size is used.
PAGE_SIZE: 64KB
pageblock_order: 13 (512MB)
MAX_ORDER: 14
This specifies the page reporting order to 5 (2MB) for this specific case
so that page reporting can be triggered.
Link: https://lkml.kernel.org/r/20210625014710.42954-5-gshan@redhat.com
Signed-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/virtio')
| -rw-r--r-- | drivers/virtio/virtio_balloon.c | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c index 510e9318854d..47dce91f788c 100644 --- a/drivers/virtio/virtio_balloon.c +++ b/drivers/virtio/virtio_balloon.c @@ -993,6 +993,23 @@ static int virtballoon_probe(struct virtio_device *vdev) goto out_unregister_oom; } + /* + * The default page reporting order is @pageblock_order, which + * corresponds to 512MB in size on ARM64 when 64KB base page + * size is used. The page reporting won't be triggered if the + * freeing page can't come up with a free area like that huge. + * So we specify the page reporting order to 5, corresponding + * to 2MB. It helps to avoid THP splitting if 4KB base page + * size is used by host. + * + * Ideally, the page reporting order is selected based on the + * host's base page size. However, it needs more work to report + * that value. The hard-coded order would be fine currently. + */ +#if defined(CONFIG_ARM64) && defined(CONFIG_ARM64_64K_PAGES) + vb->pr_dev_info.order = 5; +#endif + err = page_reporting_register(&vb->pr_dev_info); if (err) goto out_unregister_oom; |