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authorLinus Torvalds <torvalds@linux-foundation.org>2011-01-06 15:30:19 -0500
committerLinus Torvalds <torvalds@linux-foundation.org>2011-01-06 15:30:19 -0500
commitabb359450f20c32ae03039d8736f12b1d561caf5 (patch)
tree6e8723885feb66a138f19f0ff31615dc13a8d859 /lib
parentcb600d2f83c854ec3d6660063e4466431999489b (diff)
parent4e3dbdb1392a83bd21a6ff8f6bc785495058d37c (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6: (1436 commits) cassini: Use local-mac-address prom property for Cassini MAC address net: remove the duplicate #ifdef __KERNEL__ net: bridge: check the length of skb after nf_bridge_maybe_copy_header() netconsole: clarify stopping message netconsole: don't announce stopping if nothing happened cnic: Fix the type field in SPQ messages netfilter: fix export secctx error handling netfilter: fix the race when initializing nf_ct_expect_hash_rnd ipv4: IP defragmentation must be ECN aware net: r6040: Return proper error for r6040_init_one dcb: use after free in dcb_flushapp() dcb: unlock on error in dcbnl_ieee_get() net: ixp4xx_eth: Return proper error for eth_init_one include/linux/if_ether.h: Add #define ETH_P_LINK_CTL for HPNA and wlan local tunnel net: add POLLPRI to sock_def_readable() af_unix: Avoid socket->sk NULL OOPS in stream connect security hooks. net_sched: pfifo_head_drop problem mac80211: remove stray extern mac80211: implement off-channel TX using hw r-o-c offload mac80211: implement hardware offload for remain-on-channel ...
Diffstat (limited to 'lib')
-rw-r--r--lib/Kconfig3
-rw-r--r--lib/Makefile2
-rw-r--r--lib/average.c61
-rw-r--r--lib/nlattr.c22
4 files changed, 77 insertions, 11 deletions
diff --git a/lib/Kconfig b/lib/Kconfig
index fa9bf2c0619..3116aa631af 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -210,4 +210,7 @@ config GENERIC_ATOMIC64
210config LRU_CACHE 210config LRU_CACHE
211 tristate 211 tristate
212 212
213config AVERAGE
214 bool
215
213endmenu 216endmenu
diff --git a/lib/Makefile b/lib/Makefile
index 9e2db72d128..d7b6e30a3a1 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -106,6 +106,8 @@ obj-$(CONFIG_GENERIC_ATOMIC64) += atomic64.o
106 106
107obj-$(CONFIG_ATOMIC64_SELFTEST) += atomic64_test.o 107obj-$(CONFIG_ATOMIC64_SELFTEST) += atomic64_test.o
108 108
109obj-$(CONFIG_AVERAGE) += average.o
110
109hostprogs-y := gen_crc32table 111hostprogs-y := gen_crc32table
110clean-files := crc32table.h 112clean-files := crc32table.h
111 113
diff --git a/lib/average.c b/lib/average.c
new file mode 100644
index 00000000000..5576c284149
--- /dev/null
+++ b/lib/average.c
@@ -0,0 +1,61 @@
1/*
2 * lib/average.c
3 *
4 * This source code is licensed under the GNU General Public License,
5 * Version 2. See the file COPYING for more details.
6 */
7
8#include <linux/module.h>
9#include <linux/average.h>
10#include <linux/bug.h>
11#include <linux/log2.h>
12
13/**
14 * DOC: Exponentially Weighted Moving Average (EWMA)
15 *
16 * These are generic functions for calculating Exponentially Weighted Moving
17 * Averages (EWMA). We keep a structure with the EWMA parameters and a scaled
18 * up internal representation of the average value to prevent rounding errors.
19 * The factor for scaling up and the exponential weight (or decay rate) have to
20 * be specified thru the init fuction. The structure should not be accessed
21 * directly but only thru the helper functions.
22 */
23
24/**
25 * ewma_init() - Initialize EWMA parameters
26 * @avg: Average structure
27 * @factor: Factor to use for the scaled up internal value. The maximum value
28 * of averages can be ULONG_MAX/(factor*weight). For performance reasons
29 * factor has to be a power of 2.
30 * @weight: Exponential weight, or decay rate. This defines how fast the
31 * influence of older values decreases. For performance reasons weight has
32 * to be a power of 2.
33 *
34 * Initialize the EWMA parameters for a given struct ewma @avg.
35 */
36void ewma_init(struct ewma *avg, unsigned long factor, unsigned long weight)
37{
38 WARN_ON(!is_power_of_2(weight) || !is_power_of_2(factor));
39
40 avg->weight = ilog2(weight);
41 avg->factor = ilog2(factor);
42 avg->internal = 0;
43}
44EXPORT_SYMBOL(ewma_init);
45
46/**
47 * ewma_add() - Exponentially weighted moving average (EWMA)
48 * @avg: Average structure
49 * @val: Current value
50 *
51 * Add a sample to the average.
52 */
53struct ewma *ewma_add(struct ewma *avg, unsigned long val)
54{
55 avg->internal = avg->internal ?
56 (((avg->internal << avg->weight) - avg->internal) +
57 (val << avg->factor)) >> avg->weight :
58 (val << avg->factor);
59 return avg;
60}
61EXPORT_SYMBOL(ewma_add);
diff --git a/lib/nlattr.c b/lib/nlattr.c
index c4706eb98d3..00e8a02681a 100644
--- a/lib/nlattr.c
+++ b/lib/nlattr.c
@@ -15,7 +15,7 @@
15#include <linux/types.h> 15#include <linux/types.h>
16#include <net/netlink.h> 16#include <net/netlink.h>
17 17
18static u16 nla_attr_minlen[NLA_TYPE_MAX+1] __read_mostly = { 18static const u16 nla_attr_minlen[NLA_TYPE_MAX+1] = {
19 [NLA_U8] = sizeof(u8), 19 [NLA_U8] = sizeof(u8),
20 [NLA_U16] = sizeof(u16), 20 [NLA_U16] = sizeof(u16),
21 [NLA_U32] = sizeof(u32), 21 [NLA_U32] = sizeof(u32),
@@ -23,7 +23,7 @@ static u16 nla_attr_minlen[NLA_TYPE_MAX+1] __read_mostly = {
23 [NLA_NESTED] = NLA_HDRLEN, 23 [NLA_NESTED] = NLA_HDRLEN,
24}; 24};
25 25
26static int validate_nla(struct nlattr *nla, int maxtype, 26static int validate_nla(const struct nlattr *nla, int maxtype,
27 const struct nla_policy *policy) 27 const struct nla_policy *policy)
28{ 28{
29 const struct nla_policy *pt; 29 const struct nla_policy *pt;
@@ -115,10 +115,10 @@ static int validate_nla(struct nlattr *nla, int maxtype,
115 * 115 *
116 * Returns 0 on success or a negative error code. 116 * Returns 0 on success or a negative error code.
117 */ 117 */
118int nla_validate(struct nlattr *head, int len, int maxtype, 118int nla_validate(const struct nlattr *head, int len, int maxtype,
119 const struct nla_policy *policy) 119 const struct nla_policy *policy)
120{ 120{
121 struct nlattr *nla; 121 const struct nlattr *nla;
122 int rem, err; 122 int rem, err;
123 123
124 nla_for_each_attr(nla, head, len, rem) { 124 nla_for_each_attr(nla, head, len, rem) {
@@ -173,10 +173,10 @@ nla_policy_len(const struct nla_policy *p, int n)
173 * 173 *
174 * Returns 0 on success or a negative error code. 174 * Returns 0 on success or a negative error code.
175 */ 175 */
176int nla_parse(struct nlattr *tb[], int maxtype, struct nlattr *head, int len, 176int nla_parse(struct nlattr **tb, int maxtype, const struct nlattr *head,
177 const struct nla_policy *policy) 177 int len, const struct nla_policy *policy)
178{ 178{
179 struct nlattr *nla; 179 const struct nlattr *nla;
180 int rem, err; 180 int rem, err;
181 181
182 memset(tb, 0, sizeof(struct nlattr *) * (maxtype + 1)); 182 memset(tb, 0, sizeof(struct nlattr *) * (maxtype + 1));
@@ -191,7 +191,7 @@ int nla_parse(struct nlattr *tb[], int maxtype, struct nlattr *head, int len,
191 goto errout; 191 goto errout;
192 } 192 }
193 193
194 tb[type] = nla; 194 tb[type] = (struct nlattr *)nla;
195 } 195 }
196 } 196 }
197 197
@@ -212,14 +212,14 @@ errout:
212 * 212 *
213 * Returns the first attribute in the stream matching the specified type. 213 * Returns the first attribute in the stream matching the specified type.
214 */ 214 */
215struct nlattr *nla_find(struct nlattr *head, int len, int attrtype) 215struct nlattr *nla_find(const struct nlattr *head, int len, int attrtype)
216{ 216{
217 struct nlattr *nla; 217 const struct nlattr *nla;
218 int rem; 218 int rem;
219 219
220 nla_for_each_attr(nla, head, len, rem) 220 nla_for_each_attr(nla, head, len, rem)
221 if (nla_type(nla) == attrtype) 221 if (nla_type(nla) == attrtype)
222 return nla; 222 return (struct nlattr *)nla;
223 223
224 return NULL; 224 return NULL;
225} 225}