diff options
Diffstat (limited to 'Documentation/cgroups/cgroups.txt')
-rw-r--r-- | Documentation/cgroups/cgroups.txt | 60 |
1 files changed, 36 insertions, 24 deletions
diff --git a/Documentation/cgroups/cgroups.txt b/Documentation/cgroups/cgroups.txt index 0ed99f08f1f3..cd67e90003c0 100644 --- a/Documentation/cgroups/cgroups.txt +++ b/Documentation/cgroups/cgroups.txt | |||
@@ -138,11 +138,11 @@ With the ability to classify tasks differently for different resources | |||
138 | the admin can easily set up a script which receives exec notifications | 138 | the admin can easily set up a script which receives exec notifications |
139 | and depending on who is launching the browser he can | 139 | and depending on who is launching the browser he can |
140 | 140 | ||
141 | # echo browser_pid > /mnt/<restype>/<userclass>/tasks | 141 | # echo browser_pid > /sys/fs/cgroup/<restype>/<userclass>/tasks |
142 | 142 | ||
143 | With only a single hierarchy, he now would potentially have to create | 143 | With only a single hierarchy, he now would potentially have to create |
144 | a separate cgroup for every browser launched and associate it with | 144 | a separate cgroup for every browser launched and associate it with |
145 | approp network and other resource class. This may lead to | 145 | appropriate network and other resource class. This may lead to |
146 | proliferation of such cgroups. | 146 | proliferation of such cgroups. |
147 | 147 | ||
148 | Also lets say that the administrator would like to give enhanced network | 148 | Also lets say that the administrator would like to give enhanced network |
@@ -153,9 +153,9 @@ apps enhanced CPU power, | |||
153 | With ability to write pids directly to resource classes, it's just a | 153 | With ability to write pids directly to resource classes, it's just a |
154 | matter of : | 154 | matter of : |
155 | 155 | ||
156 | # echo pid > /mnt/network/<new_class>/tasks | 156 | # echo pid > /sys/fs/cgroup/network/<new_class>/tasks |
157 | (after some time) | 157 | (after some time) |
158 | # echo pid > /mnt/network/<orig_class>/tasks | 158 | # echo pid > /sys/fs/cgroup/network/<orig_class>/tasks |
159 | 159 | ||
160 | Without this ability, he would have to split the cgroup into | 160 | Without this ability, he would have to split the cgroup into |
161 | multiple separate ones and then associate the new cgroups with the | 161 | multiple separate ones and then associate the new cgroups with the |
@@ -310,21 +310,24 @@ subsystem, this is the case for the cpuset. | |||
310 | To start a new job that is to be contained within a cgroup, using | 310 | To start a new job that is to be contained within a cgroup, using |
311 | the "cpuset" cgroup subsystem, the steps are something like: | 311 | the "cpuset" cgroup subsystem, the steps are something like: |
312 | 312 | ||
313 | 1) mkdir /dev/cgroup | 313 | 1) mount -t tmpfs cgroup_root /sys/fs/cgroup |
314 | 2) mount -t cgroup -ocpuset cpuset /dev/cgroup | 314 | 2) mkdir /sys/fs/cgroup/cpuset |
315 | 3) Create the new cgroup by doing mkdir's and write's (or echo's) in | 315 | 3) mount -t cgroup -ocpuset cpuset /sys/fs/cgroup/cpuset |
316 | the /dev/cgroup virtual file system. | 316 | 4) Create the new cgroup by doing mkdir's and write's (or echo's) in |
317 | 4) Start a task that will be the "founding father" of the new job. | 317 | the /sys/fs/cgroup virtual file system. |
318 | 5) Attach that task to the new cgroup by writing its pid to the | 318 | 5) Start a task that will be the "founding father" of the new job. |
319 | /dev/cgroup tasks file for that cgroup. | 319 | 6) Attach that task to the new cgroup by writing its pid to the |
320 | 6) fork, exec or clone the job tasks from this founding father task. | 320 | /sys/fs/cgroup/cpuset/tasks file for that cgroup. |
321 | 7) fork, exec or clone the job tasks from this founding father task. | ||
321 | 322 | ||
322 | For example, the following sequence of commands will setup a cgroup | 323 | For example, the following sequence of commands will setup a cgroup |
323 | named "Charlie", containing just CPUs 2 and 3, and Memory Node 1, | 324 | named "Charlie", containing just CPUs 2 and 3, and Memory Node 1, |
324 | and then start a subshell 'sh' in that cgroup: | 325 | and then start a subshell 'sh' in that cgroup: |
325 | 326 | ||
326 | mount -t cgroup cpuset -ocpuset /dev/cgroup | 327 | mount -t tmpfs cgroup_root /sys/fs/cgroup |
327 | cd /dev/cgroup | 328 | mkdir /sys/fs/cgroup/cpuset |
329 | mount -t cgroup cpuset -ocpuset /sys/fs/cgroup/cpuset | ||
330 | cd /sys/fs/cgroup/cpuset | ||
328 | mkdir Charlie | 331 | mkdir Charlie |
329 | cd Charlie | 332 | cd Charlie |
330 | /bin/echo 2-3 > cpuset.cpus | 333 | /bin/echo 2-3 > cpuset.cpus |
@@ -345,7 +348,7 @@ Creating, modifying, using the cgroups can be done through the cgroup | |||
345 | virtual filesystem. | 348 | virtual filesystem. |
346 | 349 | ||
347 | To mount a cgroup hierarchy with all available subsystems, type: | 350 | To mount a cgroup hierarchy with all available subsystems, type: |
348 | # mount -t cgroup xxx /dev/cgroup | 351 | # mount -t cgroup xxx /sys/fs/cgroup |
349 | 352 | ||
350 | The "xxx" is not interpreted by the cgroup code, but will appear in | 353 | The "xxx" is not interpreted by the cgroup code, but will appear in |
351 | /proc/mounts so may be any useful identifying string that you like. | 354 | /proc/mounts so may be any useful identifying string that you like. |
@@ -354,23 +357,32 @@ Note: Some subsystems do not work without some user input first. For instance, | |||
354 | if cpusets are enabled the user will have to populate the cpus and mems files | 357 | if cpusets are enabled the user will have to populate the cpus and mems files |
355 | for each new cgroup created before that group can be used. | 358 | for each new cgroup created before that group can be used. |
356 | 359 | ||
360 | As explained in section `1.2 Why are cgroups needed?' you should create | ||
361 | different hierarchies of cgroups for each single resource or group of | ||
362 | resources you want to control. Therefore, you should mount a tmpfs on | ||
363 | /sys/fs/cgroup and create directories for each cgroup resource or resource | ||
364 | group. | ||
365 | |||
366 | # mount -t tmpfs cgroup_root /sys/fs/cgroup | ||
367 | # mkdir /sys/fs/cgroup/rg1 | ||
368 | |||
357 | To mount a cgroup hierarchy with just the cpuset and memory | 369 | To mount a cgroup hierarchy with just the cpuset and memory |
358 | subsystems, type: | 370 | subsystems, type: |
359 | # mount -t cgroup -o cpuset,memory hier1 /dev/cgroup | 371 | # mount -t cgroup -o cpuset,memory hier1 /sys/fs/cgroup/rg1 |
360 | 372 | ||
361 | To change the set of subsystems bound to a mounted hierarchy, just | 373 | To change the set of subsystems bound to a mounted hierarchy, just |
362 | remount with different options: | 374 | remount with different options: |
363 | # mount -o remount,cpuset,blkio hier1 /dev/cgroup | 375 | # mount -o remount,cpuset,blkio hier1 /sys/fs/cgroup/rg1 |
364 | 376 | ||
365 | Now memory is removed from the hierarchy and blkio is added. | 377 | Now memory is removed from the hierarchy and blkio is added. |
366 | 378 | ||
367 | Note this will add blkio to the hierarchy but won't remove memory or | 379 | Note this will add blkio to the hierarchy but won't remove memory or |
368 | cpuset, because the new options are appended to the old ones: | 380 | cpuset, because the new options are appended to the old ones: |
369 | # mount -o remount,blkio /dev/cgroup | 381 | # mount -o remount,blkio /sys/fs/cgroup/rg1 |
370 | 382 | ||
371 | To Specify a hierarchy's release_agent: | 383 | To Specify a hierarchy's release_agent: |
372 | # mount -t cgroup -o cpuset,release_agent="/sbin/cpuset_release_agent" \ | 384 | # mount -t cgroup -o cpuset,release_agent="/sbin/cpuset_release_agent" \ |
373 | xxx /dev/cgroup | 385 | xxx /sys/fs/cgroup/rg1 |
374 | 386 | ||
375 | Note that specifying 'release_agent' more than once will return failure. | 387 | Note that specifying 'release_agent' more than once will return failure. |
376 | 388 | ||
@@ -379,17 +391,17 @@ when the hierarchy consists of a single (root) cgroup. Supporting | |||
379 | the ability to arbitrarily bind/unbind subsystems from an existing | 391 | the ability to arbitrarily bind/unbind subsystems from an existing |
380 | cgroup hierarchy is intended to be implemented in the future. | 392 | cgroup hierarchy is intended to be implemented in the future. |
381 | 393 | ||
382 | Then under /dev/cgroup you can find a tree that corresponds to the | 394 | Then under /sys/fs/cgroup/rg1 you can find a tree that corresponds to the |
383 | tree of the cgroups in the system. For instance, /dev/cgroup | 395 | tree of the cgroups in the system. For instance, /sys/fs/cgroup/rg1 |
384 | is the cgroup that holds the whole system. | 396 | is the cgroup that holds the whole system. |
385 | 397 | ||
386 | If you want to change the value of release_agent: | 398 | If you want to change the value of release_agent: |
387 | # echo "/sbin/new_release_agent" > /dev/cgroup/release_agent | 399 | # echo "/sbin/new_release_agent" > /sys/fs/cgroup/rg1/release_agent |
388 | 400 | ||
389 | It can also be changed via remount. | 401 | It can also be changed via remount. |
390 | 402 | ||
391 | If you want to create a new cgroup under /dev/cgroup: | 403 | If you want to create a new cgroup under /sys/fs/cgroup/rg1: |
392 | # cd /dev/cgroup | 404 | # cd /sys/fs/cgroup/rg1 |
393 | # mkdir my_cgroup | 405 | # mkdir my_cgroup |
394 | 406 | ||
395 | Now you want to do something with this cgroup. | 407 | Now you want to do something with this cgroup. |