Re: [PATCH v2] mm: add a low limit to alloc_large_system_hash
From: Tim Bird <hidden>
Date: 2012-05-23 23:32:57
This patch seems to have fallen in the cracks: https://lkml.org/lkml/2012/2/27/20 The last message on the thread was an ACK by David Miller, and the question "Who wants to take this?" -- Tim [message and patch follow] UDP stack needs a minimum hash size value for proper operation and also uses alloc_large_system_hash() for proper NUMA distribution of its hash tables and automatic sizing depending on available system memory. On some low memory situations, udp_table_init() must ignore the alloc_large_system_hash() result and reallocs a bigger memory area. As we cannot easily free old hash table, we leak it and kmemleak can issue a warning. This patch adds a low limit parameter to alloc_large_system_hash() to solve this problem. We then specify UDP_HTABLE_SIZE_MIN for UDP/UDPLite hash table allocation. Reported-by: Mark Asselstine <redacted> Reported-by: Tim Bird <redacted> Signed-off-by: Eric Dumazet <redacted> Cc: Paul Gortmaker <redacted> --- V2: no 16 minimum value for pid hash fs/dcache.c | 2 ++ fs/inode.c | 2 ++ include/linux/bootmem.h | 3 ++- kernel/pid.c | 3 ++- mm/page_alloc.c | 7 +++++-- net/ipv4/route.c | 1 + net/ipv4/tcp.c | 2 ++ net/ipv4/udp.c | 30 ++++++++++-------------------- 8 files changed, 26 insertions(+), 24 deletions(-)
diff --git a/fs/dcache.c b/fs/dcache.c
index fe19ac1..ef5e72e 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c@@ -2984,6 +2984,7 @@ static void __init dcache_init_early(void) HASH_EARLY, &d_hash_shift, &d_hash_mask, + 0, 0); for (loop = 0; loop < (1U << d_hash_shift); loop++)
@@ -3014,6 +3015,7 @@ static void __init dcache_init(void) 0, &d_hash_shift, &d_hash_mask, + 0, 0); for (loop = 0; loop < (1U << d_hash_shift); loop++)
diff --git a/fs/inode.c b/fs/inode.c
index d3ebdbe..7acee4c 100644
--- a/fs/inode.c
+++ b/fs/inode.c@@ -1667,6 +1667,7 @@ void __init inode_init_early(void) HASH_EARLY, &i_hash_shift, &i_hash_mask, + 0, 0); for (loop = 0; loop < (1U << i_hash_shift); loop++)
@@ -1697,6 +1698,7 @@ void __init inode_init(void) 0, &i_hash_shift, &i_hash_mask, + 0, 0); for (loop = 0; loop < (1U << i_hash_shift); loop++)
diff --git a/include/linux/bootmem.h b/include/linux/bootmem.h
index 66d3e95..1a0cd27 100644
--- a/include/linux/bootmem.h
+++ b/include/linux/bootmem.h@@ -154,7 +154,8 @@ extern void *alloc_large_system_hash(const char *tablename, int flags, unsigned int *_hash_shift, unsigned int *_hash_mask, - unsigned long limit); + unsigned long low_limit, + unsigned long high_limit); #define HASH_EARLY 0x00000001 /* Allocating during early boot? */ #define HASH_SMALL 0x00000002 /* sub-page allocation allowed, min
diff --git a/kernel/pid.c b/kernel/pid.c
index 9f08dfa..e86b291 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c@@ -547,7 +547,8 @@ void __init pidhash_init(void) pid_hash = alloc_large_system_hash("PID", sizeof(*pid_hash), 0, 18, HASH_EARLY | HASH_SMALL, - &pidhash_shift, NULL, 4096); + &pidhash_shift, NULL, + 0, 4096); pidhash_size = 1U << pidhash_shift; for (i = 0; i < pidhash_size; i++)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index a13ded1..b9afccb 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c@@ -5198,9 +5198,10 @@ void *__init alloc_large_system_hash(const char *tablename, int flags, unsigned int *_hash_shift, unsigned int *_hash_mask, - unsigned long limit) + unsigned long low_limit, + unsigned long high_limit) { - unsigned long long max = limit; + unsigned long long max = high_limit; unsigned long log2qty, size; void *table = NULL;
@@ -5238,6 +5239,8 @@ void *__init alloc_large_system_hash(const char *tablename, } max = min(max, 0x80000000ULL); + if (numentries < low_limit) + numentries = low_limit; if (numentries > max) numentries = max;
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index bcacf54..0a41e38 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c@@ -3475,6 +3475,7 @@ int __init ip_rt_init(void) 0, &rt_hash_log, &rt_hash_mask, + 0, rhash_entries ? 0 : 512 * 1024); memset(rt_hash_table, 0, (rt_hash_mask + 1) * sizeof(struct rt_hash_bucket)); rt_hash_lock_init();
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 22ef5f9..e61a498 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c@@ -3267,6 +3267,7 @@ void __init tcp_init(void) 0, NULL, &tcp_hashinfo.ehash_mask, + 0, thash_entries ? 0 : 512 * 1024); for (i = 0; i <= tcp_hashinfo.ehash_mask; i++) { INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].chain, i);
@@ -3283,6 +3284,7 @@ void __init tcp_init(void) 0, &tcp_hashinfo.bhash_size, NULL, + 0, 64 * 1024); tcp_hashinfo.bhash_size = 1U << tcp_hashinfo.bhash_size; for (i = 0; i < tcp_hashinfo.bhash_size; i++) {
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 5d075b5..dc68ed2 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c@@ -2182,26 +2182,16 @@ void __init udp_table_init(struct udp_table *table, const char *name) { unsigned int i; - if (!CONFIG_BASE_SMALL) - table->hash = alloc_large_system_hash(name, - 2 * sizeof(struct udp_hslot), - uhash_entries, - 21, /* one slot per 2 MB */ - 0, - &table->log, - &table->mask, - 64 * 1024); - /* - * Make sure hash table has the minimum size - */ - if (CONFIG_BASE_SMALL || table->mask < UDP_HTABLE_SIZE_MIN - 1) { - table->hash = kmalloc(UDP_HTABLE_SIZE_MIN * - 2 * sizeof(struct udp_hslot), GFP_KERNEL); - if (!table->hash) - panic(name); - table->log = ilog2(UDP_HTABLE_SIZE_MIN); - table->mask = UDP_HTABLE_SIZE_MIN - 1; - } + table->hash = alloc_large_system_hash(name, + 2 * sizeof(struct udp_hslot), + uhash_entries, + 21, /* one slot per 2 MB */ + 0, + &table->log, + &table->mask, + UDP_HTABLE_SIZE_MIN, + 64 * 1024); + table->hash2 = table->hash + (table->mask + 1); for (i = 0; i <= table->mask; i++) { INIT_HLIST_NULLS_HEAD(&table->hash[i].head, i);