hulk inclusion category: bugfix bugzilla: https://atomgit.com/openeuler/kernel/issues/9122 ---------------------------------------- When onlining pre-onlined memory, numa_remote lock is held to check if the memory range is pre-onlined. However, it may lead to unstable performance when the lock is contended. So, don't check it in add_memory_remote(), only check it in numa_remote_undo_fake_online(). Fixes: c855b296345e ("mm/numa_remote: undo isolation of remote memory asynchronously") Signed-off-by: Jinjiang Tu <tujinjiang@huawei.com> --- drivers/base/numa_remote.c | 56 ++++++++++++++++---------------------- 1 file changed, 23 insertions(+), 33 deletions(-) diff --git a/drivers/base/numa_remote.c b/drivers/base/numa_remote.c index f53d1dcab2ce..fed37dc20391 100644 --- a/drivers/base/numa_remote.c +++ b/drivers/base/numa_remote.c @@ -30,6 +30,7 @@ static nodemask_t numa_nodes_remote; struct undo_fake_online_control { u64 start; u64 size; + int nid; struct llist_node llist; }; @@ -283,17 +284,14 @@ static void numa_remote_online_pages(unsigned long start_pfn, unsigned long end_ * Undo fake-online a remote node. Have to be called in preonline mode then * the memory on the node can be allocated. */ -static int __ref numa_remote_undo_fake_online(u64 start, u64 size) +static int __ref numa_remote_undo_fake_online(u64 start, u64 size, int nid) { unsigned long start_pfn = PFN_DOWN(start); unsigned long end_pfn = PFN_DOWN(start + size); unsigned long nr_pages = end_pfn - start_pfn; - struct zone *zone; - int nid; int ret = 0; mem_hotplug_begin(); - /* Re-check whether all memory block are pre-online. */ if (!check_memory_block_pre_online(start, size, true)) { ret = -EINVAL; goto out; @@ -304,8 +302,6 @@ static int __ref numa_remote_undo_fake_online(u64 start, u64 size) goto out; } - zone = page_zone(phys_to_page(start)); - nid = zone_to_nid(zone); if (!check_memory_block_nid(start, size, nid)) { ret = -EINVAL; goto out; @@ -328,6 +324,8 @@ static int __ref numa_remote_undo_fake_online(u64 start, u64 size) out: atomic_long_add(-nr_pages, &undo_fake_online_pages_node[nid]); mem_hotplug_done(); + if (unlikely(ret)) + pr_warn("online memory [%llx, %llx) failed: %d\n", start, start + size, ret); return ret; } @@ -362,7 +360,7 @@ static void undo_fake_online_work_fn(struct work_struct *work) node = node->next; mutex_lock(&numa_remote_lock); - numa_remote_undo_fake_online(uic->start, uic->size); + numa_remote_undo_fake_online(uic->start, uic->size, uic->nid); mutex_unlock(&numa_remote_lock); kfree(uic); } @@ -454,43 +452,37 @@ int add_memory_remote(int nid, u64 start, u64 size, int flags) if (flags == (MEMORY_KEEP_ISOLATED | MEMORY_DIRECT_ONLINE)) return NUMA_NO_NODE; - if (flags & (MEMORY_KEEP_ISOLATED | MEMORY_DIRECT_ONLINE)) { - numa_remote_wait_undo_fake_online(); - down_write(&numa_remote_state_lock); - } - mutex_lock(&numa_remote_lock); - - if (numa_remote_preonline_mode && !flags) { + /* Online pre-onlined memory. To avoid grabbing numa_rmeote + * lock and leading to unstable performance, don't check if + * [start, start + size) is pre-onelined, check it in the + * async work. + */ + if (!flags) { struct undo_fake_online_control *uic; if (check_hotplug_memory_range(start, size)) - goto out; - /* Check whether all memory block are pre-online. */ - if (!check_memory_block_pre_online(start, size, true)) - goto out; + return NUMA_NO_NODE; - real_nid = (nid == NUMA_NO_NODE) ? - page_to_nid(phys_to_page(start)) : nid; - if (!check_memory_block_nid(start, size, real_nid)) { - real_nid = NUMA_NO_NODE; - goto out; - } + if (nid == NUMA_NO_NODE) + return NUMA_NO_NODE; uic = kzalloc(sizeof(struct undo_fake_online_control), GFP_KERNEL); - if (!uic) { - real_nid = NUMA_NO_NODE; - goto out; - } + if (!uic) + return NUMA_NO_NODE; - atomic_long_add(size / PAGE_SIZE, &undo_fake_online_pages_node[real_nid]); + atomic_long_add(size / PAGE_SIZE, &undo_fake_online_pages_node[nid]); uic->start = start; uic->size = size; + uic->nid = nid; if (llist_add(&uic->llist, &undo_fake_online_list)) schedule_work(&undo_fake_online_work); - goto out; + return nid; } + numa_remote_wait_undo_fake_online(); + down_write(&numa_remote_state_lock); + mutex_lock(&numa_remote_lock); lock_device_hotplug(); real_nid = (nid == NUMA_NO_NODE) ? find_unused_remote_node() : nid; @@ -505,10 +497,8 @@ int add_memory_remote(int nid, u64 start, u64 size, int flags) unlock: unlock_device_hotplug(); -out: mutex_unlock(&numa_remote_lock); - if (flags & (MEMORY_KEEP_ISOLATED | MEMORY_DIRECT_ONLINE)) - up_write(&numa_remote_state_lock); + up_write(&numa_remote_state_lock); return real_nid; } EXPORT_SYMBOL_GPL(add_memory_remote); -- 2.43.0