From: David Hildenbrand <david@redhat.com>
To: linux-kernel@vger.kernel.org
Cc: virtualization@lists.linux-foundation.org, linux-mm@kvack.org,
"Michael S . Tsirkin" <mst@redhat.com>,
David Hildenbrand <david@redhat.com>,
Wei Yang <richard.weiyang@linux.alibaba.com>,
Jason Wang <jasowang@redhat.com>,
Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Subject: [PATCH v2 03/29] virtio-mem: simplify MAX_ORDER - 1 / pageblock_order handling
Date: Thu, 12 Nov 2020 14:37:49 +0100 [thread overview]
Message-ID: <20201112133815.13332-4-david@redhat.com> (raw)
In-Reply-To: <20201112133815.13332-1-david@redhat.com>
Let's use pageblock_nr_pages and MAX_ORDER_NR_PAGES instead where
possible to simplify.
Add a comment why we have that restriction for now.
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>
---
drivers/virtio/virtio_mem.c | 35 +++++++++++++++++++----------------
1 file changed, 19 insertions(+), 16 deletions(-)
diff --git a/drivers/virtio/virtio_mem.c b/drivers/virtio/virtio_mem.c
index dee46865bae2..0f9d854e8e42 100644
--- a/drivers/virtio/virtio_mem.c
+++ b/drivers/virtio/virtio_mem.c
@@ -753,14 +753,15 @@ static void virtio_mem_clear_fake_offline(unsigned long pfn,
*/
static void virtio_mem_fake_online(unsigned long pfn, unsigned int nr_pages)
{
- const int order = MAX_ORDER - 1;
+ const unsigned long max_nr_pages = MAX_ORDER_NR_PAGES;
int i;
/*
- * We are always called with subblock granularity, which is at least
- * aligned to MAX_ORDER - 1.
+ * We are always called at least with MAX_ORDER_NR_PAGES
+ * granularity/alignment (e.g., the way subblocks work). All pages
+ * inside such a block are alike.
*/
- for (i = 0; i < nr_pages; i += 1 << order) {
+ for (i = 0; i < nr_pages; i += max_nr_pages) {
struct page *page = pfn_to_page(pfn + i);
/*
@@ -770,14 +771,14 @@ static void virtio_mem_fake_online(unsigned long pfn, unsigned int nr_pages)
* alike.
*/
if (PageDirty(page)) {
- virtio_mem_clear_fake_offline(pfn + i, 1 << order,
+ virtio_mem_clear_fake_offline(pfn + i, max_nr_pages,
false);
- generic_online_page(page, order);
+ generic_online_page(page, MAX_ORDER - 1);
} else {
- virtio_mem_clear_fake_offline(pfn + i, 1 << order,
+ virtio_mem_clear_fake_offline(pfn + i, max_nr_pages,
true);
- free_contig_range(pfn + i, 1 << order);
- adjust_managed_page_count(page, 1 << order);
+ free_contig_range(pfn + i, max_nr_pages);
+ adjust_managed_page_count(page, max_nr_pages);
}
}
}
@@ -790,7 +791,7 @@ static void virtio_mem_online_page_cb(struct page *page, unsigned int order)
int sb_id;
/*
- * We exploit here that subblocks have at least MAX_ORDER - 1
+ * We exploit here that subblocks have at least MAX_ORDER_NR_PAGES.
* size/alignment and that this callback is is called with such a
* size/alignment. So we cannot cross subblocks and therefore
* also not memory blocks.
@@ -1673,13 +1674,15 @@ static int virtio_mem_init(struct virtio_mem *vm)
"Some memory is not addressable. This can make some memory unusable.\n");
/*
- * Calculate the subblock size:
- * - At least MAX_ORDER - 1 / pageblock_order.
- * - At least the device block size.
- * In the worst case, a single subblock per memory block.
+ * We want subblocks to span at least MAX_ORDER_NR_PAGES and
+ * pageblock_nr_pages pages. This:
+ * - Simplifies our page onlining code (virtio_mem_online_page_cb)
+ * and fake page onlining code (virtio_mem_fake_online).
+ * - Is required for now for alloc_contig_range() to work reliably -
+ * it doesn't properly handle smaller granularity on ZONE_NORMAL.
*/
- vm->subblock_size = PAGE_SIZE * 1ul << max_t(uint32_t, MAX_ORDER - 1,
- pageblock_order);
+ vm->subblock_size = max_t(uint64_t, MAX_ORDER_NR_PAGES,
+ pageblock_nr_pages) * PAGE_SIZE;
vm->subblock_size = max_t(uint64_t, vm->device_block_size,
vm->subblock_size);
vm->nb_sb_per_mb = memory_block_size_bytes() / vm->subblock_size;
--
2.26.2
next prev parent reply other threads:[~2020-11-12 13:38 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-12 13:37 [PATCH v2 00/29] virtio-mem: Big Block Mode (BBM) David Hildenbrand
2020-11-12 13:37 ` [PATCH v2 01/29] virtio-mem: determine nid only once using memory_add_physaddr_to_nid() David Hildenbrand
2020-11-12 13:37 ` [PATCH v2 02/29] virtio-mem: more precise calculation in virtio_mem_mb_state_prepare_next_mb() David Hildenbrand
2020-11-12 13:37 ` David Hildenbrand [this message]
2020-11-12 13:37 ` [PATCH v2 04/29] virtio-mem: drop rc2 in virtio_mem_mb_plug_and_add() David Hildenbrand
2020-11-12 13:37 ` [PATCH v2 05/29] virtio-mem: use "unsigned long" for nr_pages when fake onlining/offlining David Hildenbrand
2020-11-12 13:37 ` [PATCH v2 06/29] virtio-mem: factor out calculation of the bit number within the subblock bitmap David Hildenbrand
2020-11-12 13:37 ` [PATCH v2 07/29] virtio-mem: print debug messages from virtio_mem_send_*_request() David Hildenbrand
2020-11-12 13:37 ` [PATCH v2 08/29] virtio-mem: factor out fake-offlining into virtio_mem_fake_offline() David Hildenbrand
2020-11-12 13:37 ` [PATCH v2 09/29] virtio-mem: factor out handling of fake-offline pages in memory notifier David Hildenbrand
2020-11-12 13:37 ` [PATCH v2 10/29] virtio-mem: retry fake-offlining via alloc_contig_range() on ZONE_MOVABLE David Hildenbrand
2020-11-12 13:37 ` [PATCH v2 11/29] virtio-mem: generalize check for added memory David Hildenbrand
2020-11-12 13:37 ` [PATCH v2 12/29] virtio-mem: generalize virtio_mem_owned_mb() David Hildenbrand
2020-11-12 13:37 ` [PATCH v2 13/29] virtio-mem: generalize virtio_mem_overlaps_range() David Hildenbrand
2020-11-12 13:38 ` [PATCH v2 14/29] virtio-mem: drop last_mb_id David Hildenbrand
2020-11-12 13:38 ` [PATCH v2 15/29] virtio-mem: don't always trigger the workqueue when offlining memory David Hildenbrand
2020-11-12 13:38 ` [PATCH v2 16/29] virtio-mem: generalize handling when memory is getting onlined deferred David Hildenbrand
2020-11-12 13:38 ` [PATCH v2 17/29] virito-mem: document Sub Block Mode (SBM) David Hildenbrand
2020-11-12 13:38 ` [PATCH v2 18/29] virtio-mem: memory block states are specific to " David Hildenbrand
2020-11-12 13:38 ` [PATCH v2 19/29] virito-mem: subblock " David Hildenbrand
2020-11-12 13:38 ` [PATCH v2 20/29] virtio-mem: nb_sb_per_mb and subblock_size " David Hildenbrand
2020-11-12 13:38 ` [PATCH v2 21/29] virtio-mem: memory block ids " David Hildenbrand
2020-11-12 13:38 ` [PATCH v2 22/29] virito-mem: existing (un)plug functions " David Hildenbrand
2020-11-12 13:38 ` [PATCH v2 23/29] virtio-mem: memory notifier callbacks " David Hildenbrand
2020-11-12 13:38 ` [PATCH v2 24/29] virtio-mem: factor out adding/removing memory from Linux David Hildenbrand
2020-11-12 13:38 ` [PATCH v2 25/29] virtio-mem: Big Block Mode (BBM) memory hotplug David Hildenbrand
2020-11-12 13:38 ` [PATCH v2 26/29] virtio-mem: allow to force Big Block Mode (BBM) and set the big block size David Hildenbrand
2020-11-12 13:38 ` [PATCH v2 27/29] mm/memory_hotplug: extend offline_and_remove_memory() to handle more than one memory block David Hildenbrand
2020-11-18 4:53 ` Andrew Morton
2020-11-18 8:59 ` David Hildenbrand
2020-11-12 13:38 ` [PATCH v2 28/29] virtio-mem: Big Block Mode (BBM) - basic memory hotunplug David Hildenbrand
2020-11-12 13:38 ` [PATCH v2 29/29] virtio-mem: Big Block Mode (BBM) - safe " David Hildenbrand
2020-11-18 9:00 ` [PATCH v2 00/29] virtio-mem: Big Block Mode (BBM) Michael S. Tsirkin
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