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Diffstat (limited to 'Documentation/accounting/taskstats.rst')
| -rw-r--r-- | Documentation/accounting/taskstats.rst | 54 |
1 files changed, 28 insertions, 26 deletions
diff --git a/Documentation/accounting/taskstats.rst b/Documentation/accounting/taskstats.rst index 2a28b7f55c10..173c1e7bf5ef 100644 --- a/Documentation/accounting/taskstats.rst +++ b/Documentation/accounting/taskstats.rst @@ -76,41 +76,43 @@ The messages are in the format:: The taskstats payload is one of the following three kinds: 1. Commands: Sent from user to kernel. Commands to get data on -a pid/tgid consist of one attribute, of type TASKSTATS_CMD_ATTR_PID/TGID, -containing a u32 pid or tgid in the attribute payload. The pid/tgid denotes -the task/process for which userspace wants statistics. - -Commands to register/deregister interest in exit data from a set of cpus -consist of one attribute, of type -TASKSTATS_CMD_ATTR_REGISTER/DEREGISTER_CPUMASK and contain a cpumask in the -attribute payload. The cpumask is specified as an ascii string of -comma-separated cpu ranges e.g. to listen to exit data from cpus 1,2,3,5,7,8 -the cpumask would be "1-3,5,7-8". If userspace forgets to deregister interest -in cpus before closing the listening socket, the kernel cleans up its interest -set over time. However, for the sake of efficiency, an explicit deregistration -is advisable. + a pid/tgid consist of one attribute, of type TASKSTATS_CMD_ATTR_PID/TGID, + containing a u32 pid or tgid in the attribute payload. The pid/tgid denotes + the task/process for which userspace wants statistics. + + Commands to register/deregister interest in exit data from a set of cpus + consist of one attribute, of type + TASKSTATS_CMD_ATTR_REGISTER/DEREGISTER_CPUMASK and contain a cpumask in the + attribute payload. The cpumask is specified as an ascii string of + comma-separated cpu ranges e.g. to listen to exit data from cpus 1,2,3,5,7,8 + the cpumask would be "1-3,5,7-8". If userspace forgets to deregister + interest in cpus before closing the listening socket, the kernel cleans up + its interest set over time. However, for the sake of efficiency, an explicit + deregistration is advisable. 2. Response for a command: sent from the kernel in response to a userspace -command. The payload is a series of three attributes of type: + command. The payload is a series of three attributes of type: -a) TASKSTATS_TYPE_AGGR_PID/TGID : attribute containing no payload but indicates -a pid/tgid will be followed by some stats. + a) TASKSTATS_TYPE_AGGR_PID/TGID: attribute containing no payload but + indicates a pid/tgid will be followed by some stats. -b) TASKSTATS_TYPE_PID/TGID: attribute whose payload is the pid/tgid whose stats -are being returned. + b) TASKSTATS_TYPE_PID/TGID: attribute whose payload is the pid/tgid whose + stats are being returned. -c) TASKSTATS_TYPE_STATS: attribute with a struct taskstats as payload. The -same structure is used for both per-pid and per-tgid stats. + c) TASKSTATS_TYPE_STATS: attribute with a struct taskstats as payload. The + same structure is used for both per-pid and per-tgid stats. 3. New message sent by kernel whenever a task exits. The payload consists of a series of attributes of the following type: -a) TASKSTATS_TYPE_AGGR_PID: indicates next two attributes will be pid+stats -b) TASKSTATS_TYPE_PID: contains exiting task's pid -c) TASKSTATS_TYPE_STATS: contains the exiting task's per-pid stats -d) TASKSTATS_TYPE_AGGR_TGID: indicates next two attributes will be tgid+stats -e) TASKSTATS_TYPE_TGID: contains tgid of process to which task belongs -f) TASKSTATS_TYPE_STATS: contains the per-tgid stats for exiting task's process + a) TASKSTATS_TYPE_AGGR_PID: indicates next two attributes will be pid+stats + b) TASKSTATS_TYPE_PID: contains exiting task's pid + c) TASKSTATS_TYPE_STATS: contains the exiting task's per-pid stats + d) TASKSTATS_TYPE_AGGR_TGID: indicates next two attributes will be + tgid+stats + e) TASKSTATS_TYPE_TGID: contains tgid of process to which task belongs + f) TASKSTATS_TYPE_STATS: contains the per-tgid stats for exiting task's + process per-tgid stats |