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author | Eric Dumazet <edumazet@google.com> | 2015-05-26 07:55:34 -0700 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2015-05-26 19:48:46 -0400 |
commit | 095dc8e0c3686d586a01a50abc3e1bb9ac633054 (patch) | |
tree | 5b6b15dcfcc64e553af3587a83d70b5f859f8a45 /net/ipv4/inet_hashtables.c | |
parent | f3903bcc0091df871ac64261f65ed2e4c3519d39 (diff) | |
download | op-kernel-dev-095dc8e0c3686d586a01a50abc3e1bb9ac633054.zip op-kernel-dev-095dc8e0c3686d586a01a50abc3e1bb9ac633054.tar.gz |
tcp: fix/cleanup inet_ehash_locks_alloc()
If tcp ehash table is constrained to a very small number of buckets
(eg boot parameter thash_entries=128), then we can crash if spinlock
array has more entries.
While we are at it, un-inline inet_ehash_locks_alloc() and make
following changes :
- Budget 2 cache lines per cpu worth of 'spinlocks'
- Try to kmalloc() the array to avoid extra TLB pressure.
(Most servers at Google allocate 8192 bytes for this hash table)
- Get rid of various #ifdef
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/inet_hashtables.c')
-rw-r--r-- | net/ipv4/inet_hashtables.c | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c index 3766bdd..185efef 100644 --- a/net/ipv4/inet_hashtables.c +++ b/net/ipv4/inet_hashtables.c @@ -18,6 +18,7 @@ #include <linux/sched.h> #include <linux/slab.h> #include <linux/wait.h> +#include <linux/vmalloc.h> #include <net/inet_connection_sock.h> #include <net/inet_hashtables.h> @@ -609,3 +610,33 @@ void inet_hashinfo_init(struct inet_hashinfo *h) } } EXPORT_SYMBOL_GPL(inet_hashinfo_init); + +int inet_ehash_locks_alloc(struct inet_hashinfo *hashinfo) +{ + unsigned int i, nblocks = 1; + + if (sizeof(spinlock_t) != 0) { + /* allocate 2 cache lines or at least one spinlock per cpu */ + nblocks = max_t(unsigned int, + 2 * L1_CACHE_BYTES / sizeof(spinlock_t), + 1); + nblocks = roundup_pow_of_two(nblocks * num_possible_cpus()); + + /* no more locks than number of hash buckets */ + nblocks = min(nblocks, hashinfo->ehash_mask + 1); + + hashinfo->ehash_locks = kmalloc_array(nblocks, sizeof(spinlock_t), + GFP_KERNEL | __GFP_NOWARN); + if (!hashinfo->ehash_locks) + hashinfo->ehash_locks = vmalloc(nblocks * sizeof(spinlock_t)); + + if (!hashinfo->ehash_locks) + return -ENOMEM; + + for (i = 0; i < nblocks; i++) + spin_lock_init(&hashinfo->ehash_locks[i]); + } + hashinfo->ehash_locks_mask = nblocks - 1; + return 0; +} +EXPORT_SYMBOL_GPL(inet_ehash_locks_alloc); |