virtio-mem: factor out handling of fake-offline pages in memory notifier (7a34c77d) · Commits · 戴 / test

drivers/virtio/virtio_mem.c

+50 −23

Original line number	Diff line number	Diff line
		@@ -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);

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