[RFC PATCH v2] SLUB: enhance slub to handle memory nodes without normal memory
From: Jiang Liu
Date: Tue Jul 24 2012 - 05:56:28 EST
From: WuJianguo <wujianguo@xxxxxxxxxx>
When handling a memory node with only movable zone, function
early_kmem_cache_node_alloc() will allocate a page from remote node but
still increase object count on local node, which will trigger a BUG_ON()
as below when hot-removing this memory node. Actually there's no need to
create kmem_cache_node for memory node with only movable zone at all.
------------[ cut here ]------------
kernel BUG at mm/slub.c:3590!
invalid opcode: 0000 [#1] SMP
CPU 61
Modules linked in: autofs4 sunrpc cpufreq_ondemand acpi_cpufreq freq_table
mperf ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 ip6table_filter ip6_tables
ipv6 vfat fat dm_mirror dm_region_hash dm_log uinput iTCO_wdt
iTCO_vendor_support coretemp hwmon kvm_intel kvm crc32c_intel
ghash_clmulni_intel serio_raw pcspkr cdc_ether usbnet mii i2c_i801 i2c_core sg
lpc_ich mfd_core shpchp ioatdma i7core_edac edac_core igb dca bnx2 ext4
mbcache jbd2 sr_mod cdrom sd_mod crc_t10dif aesni_intel cryptd aes_x86_64
aes_generic bfa scsi_transport_fc scsi_tgt pata_acpi ata_generic ata_piix
megaraid_sas dm_mod [last unloaded: microcode]
Pid: 46287, comm: sh Not tainted 3.5.0-rc4-pgtable-00215-g35f0828-dirty #85
IBM System x3850 X5 -[7143O3G]-/Node 1, Processor Card
RIP: 0010:[<ffffffff81160b2a>] [<ffffffff81160b2a>]
slab_memory_callback+0x1ba/0x1c0
RSP: 0018:ffff880efdcb7c68 EFLAGS: 00010202
RAX: 0000000000000001 RBX: ffff880f7ec06100 RCX: 0000000100400001
RDX: 0000000100400002 RSI: ffff880f7ec02000 RDI: ffff880f7ec06100
RBP: ffff880efdcb7c78 R08: ffff88107b6fb098 R09: ffffffff81160a00
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000019
R13: 00000000fffffffb R14: 0000000000000000 R15: ffffffff81abe930
FS: 00007f709f342700(0000) GS:ffff880f7f3a0000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 0000003b5a874570 CR3: 0000000f0da20000 CR4: 00000000000007e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process sh (pid: 46287, threadinfo ffff880efdcb6000, task ffff880f0fa50000)
Stack:
0000000000000004 ffff880efdcb7da8 ffff880efdcb7cb8 ffffffff81524af5
0000000000000001 ffffffff81a8b620 ffffffff81a8b640 0000000000000004
ffff880efdcb7da8 00000000ffffffff ffff880efdcb7d08 ffffffff8107a89a
Call Trace:
[<ffffffff81524af5>] notifier_call_chain+0x55/0x80
[<ffffffff8107a89a>] __blocking_notifier_call_chain+0x5a/0x80
[<ffffffff8107a8d6>] blocking_notifier_call_chain+0x16/0x20
[<ffffffff81352f0b>] memory_notify+0x1b/0x20
[<ffffffff81507104>] offline_pages+0x624/0x700
[<ffffffff811619de>] remove_memory+0x1e/0x20
[<ffffffff813530cc>] memory_block_change_state+0x13c/0x2e0
[<ffffffff81153e96>] ? alloc_pages_current+0xb6/0x120
[<ffffffff81353332>] store_mem_state+0xc2/0xd0
[<ffffffff8133e190>] dev_attr_store+0x20/0x30
[<ffffffff811e2d4f>] sysfs_write_file+0xef/0x170
[<ffffffff81173e28>] vfs_write+0xc8/0x190
[<ffffffff81173ff1>] sys_write+0x51/0x90
[<ffffffff81528d29>] system_call_fastpath+0x16/0x1b
Code: 8b 3d cb fd c4 00 be d0 00 00 00 e8 71 de ff ff 48 85 c0 75 9c 48 c7 c7
c0 7f a5 81 e8 c0 89 f1 ff b8 0d 80 00 00 e9 69 fe ff ff <0f> 0b eb fe 66 90
55 48 89 e5 41 57 41 56 41 55 41 54 53 48 83
RIP [<ffffffff81160b2a>] slab_memory_callback+0x1ba/0x1c0
RSP <ffff880efdcb7c68>
---[ end trace 749e9e9a67c78c12 ]---
Signed-off-by: Jianguo Wu <wujianguo@xxxxxxxxxx>
Signed-off-by: Jiang Liu <liuj97@xxxxxxxxx>
---
mm/slub.c | 44 +++++++++++++++++++++++++++++++++-----------
1 files changed, 33 insertions(+), 11 deletions(-)
diff --git a/mm/slub.c b/mm/slub.c
index 8c691fa..3976745 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -2803,6 +2803,17 @@ static inline int alloc_kmem_cache_cpus(struct kmem_cache *s)
static struct kmem_cache *kmem_cache_node;
+static bool node_has_normal_memory(int node)
+{
+ int i;
+
+ for (i = ZONE_NORMAL; i >= 0; i--)
+ if (populated_zone(&NODE_DATA(node)->node_zones[i]))
+ return true;
+
+ return false;
+}
+
/*
* No kmalloc_node yet so do it by hand. We know that this is the first
* slab on the node for this slabcache. There are no concurrent accesses
@@ -2866,6 +2877,10 @@ static int init_kmem_cache_nodes(struct kmem_cache *s)
for_each_node_state(node, N_NORMAL_MEMORY) {
struct kmem_cache_node *n;
+ /* Do not create kmem_cache_node for node without normal memory */
+ if (!node_has_normal_memory(node))
+ continue;
+
if (slab_state == DOWN) {
early_kmem_cache_node_alloc(node);
continue;
@@ -3178,9 +3193,11 @@ static inline int kmem_cache_close(struct kmem_cache *s)
for_each_node_state(node, N_NORMAL_MEMORY) {
struct kmem_cache_node *n = get_node(s, node);
- free_partial(s, n);
- if (n->nr_partial || slabs_node(s, node))
- return 1;
+ if (n) {
+ free_partial(s, n);
+ if (n->nr_partial || slabs_node(s, node))
+ return 1;
+ }
}
free_kmem_cache_nodes(s);
return 0;
@@ -3509,7 +3526,7 @@ int kmem_cache_shrink(struct kmem_cache *s)
for_each_node_state(node, N_NORMAL_MEMORY) {
n = get_node(s, node);
- if (!n->nr_partial)
+ if (!n || !n->nr_partial)
continue;
for (i = 0; i < objects; i++)
@@ -4170,7 +4187,8 @@ static long validate_slab_cache(struct kmem_cache *s)
for_each_node_state(node, N_NORMAL_MEMORY) {
struct kmem_cache_node *n = get_node(s, node);
- count += validate_slab_node(s, n, map);
+ if (n)
+ count += validate_slab_node(s, n, map);
}
kfree(map);
return count;
@@ -4339,7 +4357,7 @@ static int list_locations(struct kmem_cache *s, char *buf,
unsigned long flags;
struct page *page;
- if (!atomic_long_read(&n->nr_slabs))
+ if (!n || !atomic_long_read(&n->nr_slabs))
continue;
spin_lock_irqsave(&n->list_lock, flags);
@@ -4534,11 +4552,13 @@ static ssize_t show_slab_objects(struct kmem_cache *s,
for_each_node_state(node, N_NORMAL_MEMORY) {
struct kmem_cache_node *n = get_node(s, node);
- if (flags & SO_TOTAL)
- x = atomic_long_read(&n->total_objects);
- else if (flags & SO_OBJECTS)
- x = atomic_long_read(&n->total_objects) -
- count_partial(n, count_free);
+ if (!n)
+ continue;
+ if (flags & SO_TOTAL)
+ x = atomic_long_read(&n->total_objects);
+ else if (flags & SO_OBJECTS)
+ x = atomic_long_read(&n->total_objects) -
+ count_partial(n, count_free);
else
x = atomic_long_read(&n->nr_slabs);
@@ -4552,6 +4572,8 @@ static ssize_t show_slab_objects(struct kmem_cache *s,
for_each_node_state(node, N_NORMAL_MEMORY) {
struct kmem_cache_node *n = get_node(s, node);
+ if (!n)
+ continue;
if (flags & SO_TOTAL)
x = count_partial(n, count_total);
else if (flags & SO_OBJECTS)
--
1.7.1
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