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author | Jeff Garzik <jgarzik@pretzel.yyz.us> | 2005-06-27 22:03:52 -0400 |
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committer | Jeff Garzik <jgarzik@pobox.com> | 2005-06-27 22:03:52 -0400 |
commit | 716b43303df605510399d6da0d0dd4e2ea376e7c (patch) | |
tree | 57412aaf516b7a10b4b81064aeda318514fec168 /Documentation | |
parent | 5696c1944a33b4434a9a1ebb6383b906afd43a10 (diff) | |
parent | c7b645f934e52a54af58142d91fb51f881f8ce26 (diff) |
Merge upstream ieee80211.h with us (us == branch 'ieee80211' of netdev-2.6)
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/block/ioprio.txt | 176 | ||||
-rw-r--r-- | Documentation/cciss.txt | 1 | ||||
-rw-r--r-- | Documentation/kernel-parameters.txt | 2 |
3 files changed, 178 insertions, 1 deletions
diff --git a/Documentation/block/ioprio.txt b/Documentation/block/ioprio.txt new file mode 100644 index 000000000000..96ccf681075e --- /dev/null +++ b/Documentation/block/ioprio.txt | |||
@@ -0,0 +1,176 @@ | |||
1 | Block io priorities | ||
2 | =================== | ||
3 | |||
4 | |||
5 | Intro | ||
6 | ----- | ||
7 | |||
8 | With the introduction of cfq v3 (aka cfq-ts or time sliced cfq), basic io | ||
9 | priorities is supported for reads on files. This enables users to io nice | ||
10 | processes or process groups, similar to what has been possible to cpu | ||
11 | scheduling for ages. This document mainly details the current possibilites | ||
12 | with cfq, other io schedulers do not support io priorities so far. | ||
13 | |||
14 | Scheduling classes | ||
15 | ------------------ | ||
16 | |||
17 | CFQ implements three generic scheduling classes that determine how io is | ||
18 | served for a process. | ||
19 | |||
20 | IOPRIO_CLASS_RT: This is the realtime io class. This scheduling class is given | ||
21 | higher priority than any other in the system, processes from this class are | ||
22 | given first access to the disk every time. Thus it needs to be used with some | ||
23 | care, one io RT process can starve the entire system. Within the RT class, | ||
24 | there are 8 levels of class data that determine exactly how much time this | ||
25 | process needs the disk for on each service. In the future this might change | ||
26 | to be more directly mappable to performance, by passing in a wanted data | ||
27 | rate instead. | ||
28 | |||
29 | IOPRIO_CLASS_BE: This is the best-effort scheduling class, which is the default | ||
30 | for any process that hasn't set a specific io priority. The class data | ||
31 | determines how much io bandwidth the process will get, it's directly mappable | ||
32 | to the cpu nice levels just more coarsely implemented. 0 is the highest | ||
33 | BE prio level, 7 is the lowest. The mapping between cpu nice level and io | ||
34 | nice level is determined as: io_nice = (cpu_nice + 20) / 5. | ||
35 | |||
36 | IOPRIO_CLASS_IDLE: This is the idle scheduling class, processes running at this | ||
37 | level only get io time when no one else needs the disk. The idle class has no | ||
38 | class data, since it doesn't really apply here. | ||
39 | |||
40 | Tools | ||
41 | ----- | ||
42 | |||
43 | See below for a sample ionice tool. Usage: | ||
44 | |||
45 | # ionice -c<class> -n<level> -p<pid> | ||
46 | |||
47 | If pid isn't given, the current process is assumed. IO priority settings | ||
48 | are inherited on fork, so you can use ionice to start the process at a given | ||
49 | level: | ||
50 | |||
51 | # ionice -c2 -n0 /bin/ls | ||
52 | |||
53 | will run ls at the best-effort scheduling class at the highest priority. | ||
54 | For a running process, you can give the pid instead: | ||
55 | |||
56 | # ionice -c1 -n2 -p100 | ||
57 | |||
58 | will change pid 100 to run at the realtime scheduling class, at priority 2. | ||
59 | |||
60 | ---> snip ionice.c tool <--- | ||
61 | |||
62 | #include <stdio.h> | ||
63 | #include <stdlib.h> | ||
64 | #include <errno.h> | ||
65 | #include <getopt.h> | ||
66 | #include <unistd.h> | ||
67 | #include <sys/ptrace.h> | ||
68 | #include <asm/unistd.h> | ||
69 | |||
70 | extern int sys_ioprio_set(int, int, int); | ||
71 | extern int sys_ioprio_get(int, int); | ||
72 | |||
73 | #if defined(__i386__) | ||
74 | #define __NR_ioprio_set 289 | ||
75 | #define __NR_ioprio_get 290 | ||
76 | #elif defined(__ppc__) | ||
77 | #define __NR_ioprio_set 273 | ||
78 | #define __NR_ioprio_get 274 | ||
79 | #elif defined(__x86_64__) | ||
80 | #define __NR_ioprio_set 251 | ||
81 | #define __NR_ioprio_get 252 | ||
82 | #elif defined(__ia64__) | ||
83 | #define __NR_ioprio_set 1274 | ||
84 | #define __NR_ioprio_get 1275 | ||
85 | #else | ||
86 | #error "Unsupported arch" | ||
87 | #endif | ||
88 | |||
89 | _syscall3(int, ioprio_set, int, which, int, who, int, ioprio); | ||
90 | _syscall2(int, ioprio_get, int, which, int, who); | ||
91 | |||
92 | enum { | ||
93 | IOPRIO_CLASS_NONE, | ||
94 | IOPRIO_CLASS_RT, | ||
95 | IOPRIO_CLASS_BE, | ||
96 | IOPRIO_CLASS_IDLE, | ||
97 | }; | ||
98 | |||
99 | enum { | ||
100 | IOPRIO_WHO_PROCESS = 1, | ||
101 | IOPRIO_WHO_PGRP, | ||
102 | IOPRIO_WHO_USER, | ||
103 | }; | ||
104 | |||
105 | #define IOPRIO_CLASS_SHIFT 13 | ||
106 | |||
107 | const char *to_prio[] = { "none", "realtime", "best-effort", "idle", }; | ||
108 | |||
109 | int main(int argc, char *argv[]) | ||
110 | { | ||
111 | int ioprio = 4, set = 0, ioprio_class = IOPRIO_CLASS_BE; | ||
112 | int c, pid = 0; | ||
113 | |||
114 | while ((c = getopt(argc, argv, "+n:c:p:")) != EOF) { | ||
115 | switch (c) { | ||
116 | case 'n': | ||
117 | ioprio = strtol(optarg, NULL, 10); | ||
118 | set = 1; | ||
119 | break; | ||
120 | case 'c': | ||
121 | ioprio_class = strtol(optarg, NULL, 10); | ||
122 | set = 1; | ||
123 | break; | ||
124 | case 'p': | ||
125 | pid = strtol(optarg, NULL, 10); | ||
126 | break; | ||
127 | } | ||
128 | } | ||
129 | |||
130 | switch (ioprio_class) { | ||
131 | case IOPRIO_CLASS_NONE: | ||
132 | ioprio_class = IOPRIO_CLASS_BE; | ||
133 | break; | ||
134 | case IOPRIO_CLASS_RT: | ||
135 | case IOPRIO_CLASS_BE: | ||
136 | break; | ||
137 | case IOPRIO_CLASS_IDLE: | ||
138 | ioprio = 7; | ||
139 | break; | ||
140 | default: | ||
141 | printf("bad prio class %d\n", ioprio_class); | ||
142 | return 1; | ||
143 | } | ||
144 | |||
145 | if (!set) { | ||
146 | if (!pid && argv[optind]) | ||
147 | pid = strtol(argv[optind], NULL, 10); | ||
148 | |||
149 | ioprio = ioprio_get(IOPRIO_WHO_PROCESS, pid); | ||
150 | |||
151 | printf("pid=%d, %d\n", pid, ioprio); | ||
152 | |||
153 | if (ioprio == -1) | ||
154 | perror("ioprio_get"); | ||
155 | else { | ||
156 | ioprio_class = ioprio >> IOPRIO_CLASS_SHIFT; | ||
157 | ioprio = ioprio & 0xff; | ||
158 | printf("%s: prio %d\n", to_prio[ioprio_class], ioprio); | ||
159 | } | ||
160 | } else { | ||
161 | if (ioprio_set(IOPRIO_WHO_PROCESS, pid, ioprio | ioprio_class << IOPRIO_CLASS_SHIFT) == -1) { | ||
162 | perror("ioprio_set"); | ||
163 | return 1; | ||
164 | } | ||
165 | |||
166 | if (argv[optind]) | ||
167 | execvp(argv[optind], &argv[optind]); | ||
168 | } | ||
169 | |||
170 | return 0; | ||
171 | } | ||
172 | |||
173 | ---> snip ionice.c tool <--- | ||
174 | |||
175 | |||
176 | March 11 2005, Jens Axboe <axboe@suse.de> | ||
diff --git a/Documentation/cciss.txt b/Documentation/cciss.txt index d599beb9df8a..c8f9a73111da 100644 --- a/Documentation/cciss.txt +++ b/Documentation/cciss.txt | |||
@@ -17,6 +17,7 @@ This driver is known to work with the following cards: | |||
17 | * SA P600 | 17 | * SA P600 |
18 | * SA P800 | 18 | * SA P800 |
19 | * SA E400 | 19 | * SA E400 |
20 | * SA E300 | ||
20 | 21 | ||
21 | If nodes are not already created in the /dev/cciss directory, run as root: | 22 | If nodes are not already created in the /dev/cciss directory, run as root: |
22 | 23 | ||
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index f44bb5567c5b..89cd417651e0 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt | |||
@@ -1115,7 +1115,7 @@ running once the system is up. | |||
1115 | See Documentation/ramdisk.txt. | 1115 | See Documentation/ramdisk.txt. |
1116 | 1116 | ||
1117 | psmouse.proto= [HW,MOUSE] Highest PS2 mouse protocol extension to | 1117 | psmouse.proto= [HW,MOUSE] Highest PS2 mouse protocol extension to |
1118 | probe for (bare|imps|exps). | 1118 | probe for (bare|imps|exps|lifebook|any). |
1119 | psmouse.rate= [HW,MOUSE] Set desired mouse report rate, in reports | 1119 | psmouse.rate= [HW,MOUSE] Set desired mouse report rate, in reports |
1120 | per second. | 1120 | per second. |
1121 | psmouse.resetafter= | 1121 | psmouse.resetafter= |