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From: Wei Yang <richard.weiyang@linux.alibaba.com>
To: David Hildenbrand <david@redhat.com>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
	virtualization@lists.linux-foundation.org,
	Andrew Morton <akpm@linux-foundation.org>,
	"Michael S . Tsirkin" <mst@redhat.com>,
	Jason Wang <jasowang@redhat.com>,
	Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Subject: Re: [PATCH v1 23/29] virtio-mem: factor out adding/removing memory from Linux
Date: Fri, 16 Oct 2020 16:59:53 +0800	[thread overview]
Message-ID: <20201016085953.GF44269@L-31X9LVDL-1304.local> (raw)
In-Reply-To: <20201012125323.17509-24-david@redhat.com>

On Mon, Oct 12, 2020 at 02:53:17PM +0200, David Hildenbrand wrote:
>Let's use wrappers for the low-level functions that dev_dbg/dev_warn
>and work on addr + size, such that we can reuse them for adding/removing
>in other granularity.
>
>We only warn when adding memory failed, because that's something to pay
>attention to. We won't warn when removing failed, we'll reuse that in
>racy context soon (and we do have proper BUG_ON() statements in the
>current cases where it must never happen).
>
>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>

Reviewed-by: Wei Yang <richard.weiyang@linux.alibaba.com>

>---
> drivers/virtio/virtio_mem.c | 107 ++++++++++++++++++++++++------------
> 1 file changed, 73 insertions(+), 34 deletions(-)
>
>diff --git a/drivers/virtio/virtio_mem.c b/drivers/virtio/virtio_mem.c
>index d3ab04f655ee..eb2ad31a8d8a 100644
>--- a/drivers/virtio/virtio_mem.c
>+++ b/drivers/virtio/virtio_mem.c
>@@ -453,18 +453,16 @@ static bool virtio_mem_could_add_memory(struct virtio_mem *vm, uint64_t size)
> }
> 
> /*
>- * Try to add a memory block to Linux. This will usually only fail
>- * if out of memory.
>+ * Try adding memory to Linux. Will usually only fail if out of memory.
>  *
>  * Must not be called with the vm->hotplug_mutex held (possible deadlock with
>  * onlining code).
>  *
>- * Will not modify the state of the memory block.
>+ * Will not modify the state of memory blocks in virtio-mem.
>  */
>-static int virtio_mem_mb_add(struct virtio_mem *vm, unsigned long mb_id)
>+static int virtio_mem_add_memory(struct virtio_mem *vm, uint64_t addr,
>+				 uint64_t size)
> {
>-	const uint64_t addr = virtio_mem_mb_id_to_phys(mb_id);
>-	const uint64_t size = memory_block_size_bytes();
> 	int rc;
> 
> 	/*
>@@ -478,32 +476,50 @@ static int virtio_mem_mb_add(struct virtio_mem *vm, unsigned long mb_id)
> 			return -ENOMEM;
> 	}
> 
>-	dev_dbg(&vm->vdev->dev, "adding memory block: %lu\n", mb_id);
>+	dev_dbg(&vm->vdev->dev, "adding memory: 0x%llx - 0x%llx\n", addr,
>+		addr + size - 1);
> 	/* Memory might get onlined immediately. */
> 	atomic64_add(size, &vm->offline_size);
> 	rc = add_memory_driver_managed(vm->nid, addr, size, vm->resource_name,
> 				       MEMHP_MERGE_RESOURCE);
>-	if (rc)
>+	if (rc) {
> 		atomic64_sub(size, &vm->offline_size);
>+		dev_warn(&vm->vdev->dev, "adding memory failed: %d\n", rc);
>+		/*
>+		 * TODO: Linux MM does not properly clean up yet in all cases
>+		 * where adding of memory failed - especially on -ENOMEM.
>+		 */
>+	}
> 	return rc;
> }
> 
> /*
>- * Try to remove a memory block from Linux. Will only fail if the memory block
>- * is not offline.
>+ * See virtio_mem_add_memory(): Try adding a single Linux memory block.
>+ */
>+static int virtio_mem_sbm_add_mb(struct virtio_mem *vm, unsigned long mb_id)
>+{
>+	const uint64_t addr = virtio_mem_mb_id_to_phys(mb_id);
>+	const uint64_t size = memory_block_size_bytes();
>+
>+	return virtio_mem_add_memory(vm, addr, size);
>+}
>+
>+/*
>+ * Try removing memory from Linux. Will only fail if memory blocks aren't
>+ * offline.
>  *
>  * Must not be called with the vm->hotplug_mutex held (possible deadlock with
>  * onlining code).
>  *
>- * Will not modify the state of the memory block.
>+ * Will not modify the state of memory blocks in virtio-mem.
>  */
>-static int virtio_mem_mb_remove(struct virtio_mem *vm, unsigned long mb_id)
>+static int virtio_mem_remove_memory(struct virtio_mem *vm, uint64_t addr,
>+				    uint64_t size)
> {
>-	const uint64_t addr = virtio_mem_mb_id_to_phys(mb_id);
>-	const uint64_t size = memory_block_size_bytes();
> 	int rc;
> 
>-	dev_dbg(&vm->vdev->dev, "removing memory block: %lu\n", mb_id);
>+	dev_dbg(&vm->vdev->dev, "removing memory: 0x%llx - 0x%llx\n", addr,
>+		addr + size - 1);
> 	rc = remove_memory(vm->nid, addr, size);
> 	if (!rc) {
> 		atomic64_sub(size, &vm->offline_size);
>@@ -512,27 +528,41 @@ static int virtio_mem_mb_remove(struct virtio_mem *vm, unsigned long mb_id)
> 		 * immediately instead of waiting.
> 		 */
> 		virtio_mem_retry(vm);
>+	} else {
>+		dev_dbg(&vm->vdev->dev, "removing memory failed: %d\n", rc);
> 	}
> 	return rc;
> }
> 
> /*
>- * Try to offline and remove a memory block from Linux.
>+ * See virtio_mem_remove_memory(): Try removing a single Linux memory block.
>+ */
>+static int virtio_mem_sbm_remove_mb(struct virtio_mem *vm, unsigned long mb_id)
>+{
>+	const uint64_t addr = virtio_mem_mb_id_to_phys(mb_id);
>+	const uint64_t size = memory_block_size_bytes();
>+
>+	return virtio_mem_remove_memory(vm, addr, size);
>+}
>+
>+/*
>+ * Try offlining and removing memory from Linux.
>  *
>  * Must not be called with the vm->hotplug_mutex held (possible deadlock with
>  * onlining code).
>  *
>- * Will not modify the state of the memory block.
>+ * Will not modify the state of memory blocks in virtio-mem.
>  */
>-static int virtio_mem_mb_offline_and_remove(struct virtio_mem *vm,
>-					    unsigned long mb_id)
>+static int virtio_mem_offline_and_remove_memory(struct virtio_mem *vm,
>+						uint64_t addr,
>+						uint64_t size)
> {
>-	const uint64_t addr = virtio_mem_mb_id_to_phys(mb_id);
>-	const uint64_t size = memory_block_size_bytes();
> 	int rc;
> 
>-	dev_dbg(&vm->vdev->dev, "offlining and removing memory block: %lu\n",
>-		mb_id);
>+	dev_dbg(&vm->vdev->dev,
>+		"offlining and removing memory: 0x%llx - 0x%llx\n", addr,
>+		addr + size - 1);
>+
> 	rc = offline_and_remove_memory(vm->nid, addr, size);
> 	if (!rc) {
> 		atomic64_sub(size, &vm->offline_size);
>@@ -541,10 +571,26 @@ static int virtio_mem_mb_offline_and_remove(struct virtio_mem *vm,
> 		 * immediately instead of waiting.
> 		 */
> 		virtio_mem_retry(vm);
>+	} else {
>+		dev_dbg(&vm->vdev->dev,
>+			"offlining and removing memory failed: %d\n", rc);
> 	}
> 	return rc;
> }
> 
>+/*
>+ * See virtio_mem_offline_and_remove_memory(): Try offlining and removing
>+ * a single Linux memory block.
>+ */
>+static int virtio_mem_sbm_offline_and_remove_mb(struct virtio_mem *vm,
>+						unsigned long mb_id)
>+{
>+	const uint64_t addr = virtio_mem_mb_id_to_phys(mb_id);
>+	const uint64_t size = memory_block_size_bytes();
>+
>+	return virtio_mem_offline_and_remove_memory(vm, addr, size);
>+}
>+
> /*
>  * Trigger the workqueue so the device can perform its magic.
>  */
>@@ -1230,17 +1276,10 @@ static int virtio_mem_sbm_plug_and_add_mb(struct virtio_mem *vm,
> 					    VIRTIO_MEM_SBM_MB_OFFLINE_PARTIAL);
> 
> 	/* Add the memory block to linux - if that fails, try to unplug. */
>-	rc = virtio_mem_mb_add(vm, mb_id);
>+	rc = virtio_mem_sbm_add_mb(vm, mb_id);
> 	if (rc) {
> 		int new_state = VIRTIO_MEM_SBM_MB_UNUSED;
> 
>-		dev_err(&vm->vdev->dev,
>-			"adding memory block %lu failed with %d\n", mb_id, rc);
>-
>-		/*
>-		 * TODO: Linux MM does not properly clean up yet in all cases
>-		 * where adding of memory failed - especially on -ENOMEM.
>-		 */
> 		if (virtio_mem_sbm_unplug_sb(vm, mb_id, 0, count))
> 			new_state = VIRTIO_MEM_SBM_MB_PLUGGED;
> 		virtio_mem_sbm_set_mb_state(vm, mb_id, new_state);
>@@ -1411,7 +1450,7 @@ static int virtio_mem_sbm_unplug_any_sb_offline(struct virtio_mem *vm,
> 					    VIRTIO_MEM_SBM_MB_UNUSED);
> 
> 		mutex_unlock(&vm->hotplug_mutex);
>-		rc = virtio_mem_mb_remove(vm, mb_id);
>+		rc = virtio_mem_sbm_remove_mb(vm, mb_id);
> 		BUG_ON(rc);
> 		mutex_lock(&vm->hotplug_mutex);
> 	}
>@@ -1504,7 +1543,7 @@ static int virtio_mem_sbm_unplug_any_sb_online(struct virtio_mem *vm,
> 	 */
> 	if (virtio_mem_sbm_test_sb_unplugged(vm, mb_id, 0, vm->sbm.sbs_per_mb)) {
> 		mutex_unlock(&vm->hotplug_mutex);
>-		rc = virtio_mem_mb_offline_and_remove(vm, mb_id);
>+		rc = virtio_mem_sbm_offline_and_remove_mb(vm, mb_id);
> 		mutex_lock(&vm->hotplug_mutex);
> 		if (!rc)
> 			virtio_mem_sbm_set_mb_state(vm, mb_id,
>@@ -1991,7 +2030,7 @@ static void virtio_mem_remove(struct virtio_device *vdev)
> 	 */
> 	virtio_mem_sbm_for_each_mb(vm, mb_id,
> 				   VIRTIO_MEM_SBM_MB_OFFLINE_PARTIAL) {
>-		rc = virtio_mem_mb_remove(vm, mb_id);
>+		rc = virtio_mem_sbm_remove_mb(vm, mb_id);
> 		BUG_ON(rc);
> 		virtio_mem_sbm_set_mb_state(vm, mb_id,
> 					    VIRTIO_MEM_SBM_MB_UNUSED);
>-- 
>2.26.2

-- 
Wei Yang
Help you, Help me


  reply	other threads:[~2020-10-16  9:00 UTC|newest]

Thread overview: 109+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-12 12:52 [PATCH v1 00/29] virtio-mem: Big Block Mode (BBM) David Hildenbrand
2020-10-12 12:52 ` [PATCH v1 01/29] virtio-mem: determine nid only once using memory_add_physaddr_to_nid() David Hildenbrand
2020-10-15  3:56   ` Wei Yang
2020-10-15 19:26   ` Pankaj Gupta
2020-10-12 12:52 ` [PATCH v1 02/29] virtio-mem: simplify calculation in virtio_mem_mb_state_prepare_next_mb() David Hildenbrand
2020-10-15  4:02   ` Wei Yang
2020-10-15  8:00     ` David Hildenbrand
2020-10-15 10:00       ` Wei Yang
2020-10-15 10:01         ` David Hildenbrand
2020-10-15 20:24   ` Pankaj Gupta
2020-10-16  9:00     ` David Hildenbrand
2020-10-12 12:52 ` [PATCH v1 03/29] virtio-mem: simplify MAX_ORDER - 1 / pageblock_order handling David Hildenbrand
2020-10-15  7:06   ` Wei Yang
2020-10-12 12:52 ` [PATCH v1 04/29] virtio-mem: drop rc2 in virtio_mem_mb_plug_and_add() David Hildenbrand
2020-10-12 13:09   ` Pankaj Gupta
2020-10-15  7:14   ` Wei Yang
2020-10-12 12:52 ` [PATCH v1 05/29] virtio-mem: generalize check for added memory David Hildenbrand
2020-10-15  8:28   ` Wei Yang
2020-10-15  8:50     ` David Hildenbrand
2020-10-16  2:16       ` Wei Yang
2020-10-16  9:11         ` David Hildenbrand
2020-10-16 10:02           ` Wei Yang
2020-10-16 10:32             ` David Hildenbrand
2020-10-16 22:38               ` Wei Yang
2020-10-17  7:39                 ` David Hildenbrand
2020-10-18 12:27                   ` Wei Yang
2020-10-16 22:39   ` Wei Yang
2020-10-12 12:53 ` [PATCH v1 06/29] virtio-mem: generalize virtio_mem_owned_mb() David Hildenbrand
2020-10-15  8:32   ` Wei Yang
2020-10-15  8:37     ` David Hildenbrand
2020-10-15 20:30   ` Pankaj Gupta
2020-10-12 12:53 ` [PATCH v1 07/29] virtio-mem: generalize virtio_mem_overlaps_range() David Hildenbrand
2020-10-20  9:22   ` Pankaj Gupta
2020-10-12 12:53 ` [PATCH v1 08/29] virtio-mem: drop last_mb_id David Hildenbrand
2020-10-15  8:35   ` Wei Yang
2020-10-15 20:32   ` Pankaj Gupta
2020-10-12 12:53 ` [PATCH v1 09/29] virtio-mem: don't always trigger the workqueue when offlining memory David Hildenbrand
2020-10-16  4:03   ` Wei Yang
2020-10-16  9:18     ` David Hildenbrand
2020-10-18  3:57       ` Wei Yang
2020-10-19  9:04         ` David Hildenbrand
2020-10-20  0:41           ` Wei Yang
2020-10-20  9:09             ` David Hildenbrand
2020-10-12 12:53 ` [PATCH v1 10/29] virtio-mem: generalize handling when memory is getting onlined deferred David Hildenbrand
2020-10-12 12:53 ` [PATCH v1 11/29] virtio-mem: use "unsigned long" for nr_pages when fake onlining/offlining David Hildenbrand
2020-10-15 20:31   ` Pankaj Gupta
2020-10-16  6:11   ` Wei Yang
2020-10-12 12:53 ` [PATCH v1 12/29] virtio-mem: factor out fake-offlining into virtio_mem_fake_offline() David Hildenbrand
2020-10-16  6:24   ` Wei Yang
2020-10-20  9:31   ` Pankaj Gupta
2020-10-12 12:53 ` [PATCH v1 13/29] virtio-mem: factor out handling of fake-offline pages in memory notifier David Hildenbrand
2020-10-16  7:15   ` Wei Yang
2020-10-16  8:00     ` Wei Yang
2020-10-16  8:57       ` David Hildenbrand
2020-10-18 12:37         ` Wei Yang
2020-10-18 12:38   ` Wei Yang
2020-10-12 12:53 ` [PATCH v1 14/29] virtio-mem: retry fake-offlining via alloc_contig_range() on ZONE_MOVABLE David Hildenbrand
2020-10-12 12:53 ` [PATCH v1 15/29] virito-mem: document Sub Block Mode (SBM) David Hildenbrand
2020-10-15  9:33   ` David Hildenbrand
2020-10-20  9:38     ` Pankaj Gupta
2020-10-16  8:03   ` Wei Yang
2020-10-12 12:53 ` [PATCH v1 16/29] virtio-mem: memory block states are specific to " David Hildenbrand
2020-10-16  8:40   ` Wei Yang
2020-10-16  8:43   ` Wei Yang
2020-10-20  9:48   ` Pankaj Gupta
2020-10-12 12:53 ` [PATCH v1 17/29] virito-mem: subblock " David Hildenbrand
2020-10-16  8:43   ` Wei Yang
2020-10-20  9:54   ` Pankaj Gupta
2020-10-12 12:53 ` [PATCH v1 18/29] virtio-mem: factor out calculation of the bit number within the sb_states bitmap David Hildenbrand
2020-10-16  8:46   ` Wei Yang
2020-10-20  9:58   ` Pankaj Gupta
2020-10-12 12:53 ` [PATCH v1 19/29] virito-mem: existing (un)plug functions are specific to Sub Block Mode (SBM) David Hildenbrand
2020-10-16  8:49   ` Wei Yang
2020-10-12 12:53 ` [PATCH v1 20/29] virtio-mem: nb_sb_per_mb and subblock_size " David Hildenbrand
2020-10-16  8:51   ` Wei Yang
2020-10-16  8:53   ` Wei Yang
2020-10-16 13:17     ` David Hildenbrand
2020-10-18 12:41       ` Wei Yang
2020-10-19 11:57         ` David Hildenbrand
2020-10-12 12:53 ` [PATCH v1 21/29] virtio-mem: memory notifier callbacks " David Hildenbrand
2020-10-19  1:57   ` Wei Yang
2020-10-19 10:22     ` David Hildenbrand
2020-10-12 12:53 ` [PATCH v1 22/29] virtio-mem: memory block ids " David Hildenbrand
2020-10-16  8:54   ` Wei Yang
2020-10-12 12:53 ` [PATCH v1 23/29] virtio-mem: factor out adding/removing memory from Linux David Hildenbrand
2020-10-16  8:59   ` Wei Yang [this message]
2020-10-12 12:53 ` [PATCH v1 24/29] virtio-mem: print debug messages from virtio_mem_send_*_request() David Hildenbrand
2020-10-16  9:07   ` Wei Yang
2020-10-12 12:53 ` [PATCH v1 25/29] virtio-mem: Big Block Mode (BBM) memory hotplug David Hildenbrand
2020-10-16  9:38   ` Wei Yang
2020-10-16 13:13     ` David Hildenbrand
2020-10-19  2:26   ` Wei Yang
2020-10-19  9:15     ` David Hildenbrand
2020-10-12 12:53 ` [PATCH v1 26/29] virtio-mem: allow to force Big Block Mode (BBM) and set the big block size David Hildenbrand
2020-10-12 12:53 ` [PATCH v1 27/29] mm/memory_hotplug: extend offline_and_remove_memory() to handle more than one memory block David Hildenbrand
2020-10-15 13:08   ` Michael S. Tsirkin
2020-10-19  3:22   ` Wei Yang
2020-10-12 12:53 ` [PATCH v1 28/29] virtio-mem: Big Block Mode (BBM) - basic memory hotunplug David Hildenbrand
2020-10-19  3:48   ` Wei Yang
2020-10-19  9:12     ` David Hildenbrand
2020-10-12 12:53 ` [PATCH v1 29/29] virtio-mem: Big Block Mode (BBM) - safe " David Hildenbrand
2020-10-19  7:54   ` Wei Yang
2020-10-19  8:50     ` David Hildenbrand
2020-10-20  0:23       ` Wei Yang
2020-10-20  0:24   ` Wei Yang
2020-10-18 12:49 ` [PATCH v1 00/29] virtio-mem: Big Block Mode (BBM) Wei Yang
2020-10-18 16:35   ` David Hildenbrand
2020-10-18 15:29 ` Michael S. Tsirkin
2020-10-18 16:34   ` David Hildenbrand

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