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author | David Hildenbrand <david@redhat.com> | 2020-11-12 16:37:55 +0300 |
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committer | Michael S. Tsirkin <mst@redhat.com> | 2020-12-19 00:14:26 +0300 |
commit | 7a34c77dab7e0c7ecb58da8bf600b7aadb4d878c (patch) | |
tree | ea88c9cd4947f270cc57aee4de4e6868215c0e98 /drivers/virtio | |
parent | 89c486c47f2a450d7f064b4927b7f0ab911569a4 (diff) | |
download | linux-7a34c77dab7e0c7ecb58da8bf600b7aadb4d878c.tar.xz |
virtio-mem: factor out handling of fake-offline pages in memory notifier
Let's factor out the core pieces and place the implementation next to
virtio_mem_fake_offline(). We'll reuse this functionality soon.
Reviewed-by: Wei Yang <richard.weiyang@linux.alibaba.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20201112133815.13332-10-david@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'drivers/virtio')
-rw-r--r-- | drivers/virtio/virtio_mem.c | 73 |
1 files changed, 50 insertions, 23 deletions
diff --git a/drivers/virtio/virtio_mem.c b/drivers/virtio/virtio_mem.c index fedfea27967e..c24055248f9d 100644 --- a/drivers/virtio/virtio_mem.c +++ b/drivers/virtio/virtio_mem.c @@ -160,6 +160,10 @@ static DEFINE_MUTEX(virtio_mem_mutex); static LIST_HEAD(virtio_mem_devices); static void virtio_mem_online_page_cb(struct page *page, unsigned int order); +static void virtio_mem_fake_offline_going_offline(unsigned long pfn, + unsigned long nr_pages); +static void virtio_mem_fake_offline_cancel_offline(unsigned long pfn, + unsigned long nr_pages); /* * Register a virtio-mem device so it will be considered for the online_page @@ -586,27 +590,15 @@ static void virtio_mem_notify_going_offline(struct virtio_mem *vm, unsigned long mb_id) { const unsigned long nr_pages = PFN_DOWN(vm->subblock_size); - struct page *page; unsigned long pfn; - int sb_id, i; + int sb_id; for (sb_id = 0; sb_id < vm->nb_sb_per_mb; sb_id++) { if (virtio_mem_mb_test_sb_plugged(vm, mb_id, sb_id, 1)) continue; - /* - * Drop our reference to the pages so the memory can get - * offlined and add the unplugged pages to the managed - * page counters (so offlining code can correctly subtract - * them again). - */ pfn = PFN_DOWN(virtio_mem_mb_id_to_phys(mb_id) + sb_id * vm->subblock_size); - adjust_managed_page_count(pfn_to_page(pfn), nr_pages); - for (i = 0; i < nr_pages; i++) { - page = pfn_to_page(pfn + i); - if (WARN_ON(!page_ref_dec_and_test(page))) - dump_page(page, "unplugged page referenced"); - } + virtio_mem_fake_offline_going_offline(pfn, nr_pages); } } @@ -615,21 +607,14 @@ static void virtio_mem_notify_cancel_offline(struct virtio_mem *vm, { const unsigned long nr_pages = PFN_DOWN(vm->subblock_size); unsigned long pfn; - int sb_id, i; + int sb_id; for (sb_id = 0; sb_id < vm->nb_sb_per_mb; sb_id++) { if (virtio_mem_mb_test_sb_plugged(vm, mb_id, sb_id, 1)) continue; - /* - * Get the reference we dropped when going offline and - * subtract the unplugged pages from the managed page - * counters. - */ pfn = PFN_DOWN(virtio_mem_mb_id_to_phys(mb_id) + sb_id * vm->subblock_size); - adjust_managed_page_count(pfn_to_page(pfn), -nr_pages); - for (i = 0; i < nr_pages; i++) - page_ref_inc(pfn_to_page(pfn + i)); + virtio_mem_fake_offline_cancel_offline(pfn, nr_pages); } } @@ -814,6 +799,48 @@ static int virtio_mem_fake_offline(unsigned long pfn, unsigned long nr_pages) return 0; } +/* + * Handle fake-offline pages when memory is going offline - such that the + * pages can be skipped by mm-core when offlining. + */ +static void virtio_mem_fake_offline_going_offline(unsigned long pfn, + unsigned long nr_pages) +{ + struct page *page; + unsigned long i; + + /* + * Drop our reference to the pages so the memory can get offlined + * and add the unplugged pages to the managed page counters (so + * offlining code can correctly subtract them again). + */ + adjust_managed_page_count(pfn_to_page(pfn), nr_pages); + /* Drop our reference to the pages so the memory can get offlined. */ + for (i = 0; i < nr_pages; i++) { + page = pfn_to_page(pfn + i); + if (WARN_ON(!page_ref_dec_and_test(page))) + dump_page(page, "fake-offline page referenced"); + } +} + +/* + * Handle fake-offline pages when memory offlining is canceled - to undo + * what we did in virtio_mem_fake_offline_going_offline(). + */ +static void virtio_mem_fake_offline_cancel_offline(unsigned long pfn, + unsigned long nr_pages) +{ + unsigned long i; + + /* + * Get the reference we dropped when going offline and subtract the + * unplugged pages from the managed page counters. + */ + adjust_managed_page_count(pfn_to_page(pfn), -nr_pages); + for (i = 0; i < nr_pages; i++) + page_ref_inc(pfn_to_page(pfn + i)); +} + static void virtio_mem_online_page_cb(struct page *page, unsigned int order) { const unsigned long addr = page_to_phys(page); |