Le 15/07/2016 12:35, Topi Miettinen a écrit :
> There are many basic ways to control processes, including capabilities,
> cgroups and resource limits. However, there are far fewer ways to find out
> useful values for the limits, except blind trial and error.
>
> Prepare a foundation for resource highwater tracking.
>
> The collected highwater marks for the resources can be seen using
> taskstats netlink interface.
>
> This depends on CONFIG_TASK_XACCT.
>
> Signed-off-by: Topi Miettinen <toiwo...@gmail.com>
> ---
[snip]
> @@ -63,6 +65,8 @@ int print_task_context_switch_counts;
> /* Maximum number of cpus expected to be specified in a cpumask */
> #define MAX_CPUS 32
>
> +#define TASKSTATS_VERSION_WITH_RESOURCE 9
> +
> struct msgtemplate {
> struct nlmsghdr n;
> struct genlmsghdr g;
[snip]
> @@ -252,6 +276,22 @@ static void print_ioacct(struct taskstats *t)
> (unsigned long long)t->cancelled_write_bytes);
> }
>
> +static void print_racct(const struct taskstats *t)
> +{
> + int i;
> +
> + if (t->version < TASKSTATS_VERSION_WITH_RESOURCE) {
> + printf("kernel too old (%d < %d)\n", t->version,
> + TASKSTATS_VERSION_WITH_RESOURCE);
> + return;
> + }
[snip]
> diff --git a/include/uapi/linux/taskstats.h b/include/uapi/linux/taskstats.h
> index 2466e55..8c65194 100644
> --- a/include/uapi/linux/taskstats.h
> +++ b/include/uapi/linux/taskstats.h
> @@ -33,7 +33,7 @@
> */
>
>
> -#define TASKSTATS_VERSION 8
> +#define TASKSTATS_VERSION 9
> #define TS_COMM_LEN 32 /* should be >= TASK_COMM_LEN
> * in linux/sched.h */
>
> @@ -163,6 +163,14 @@ struct taskstats {
> /* Delay waiting for memory reclaim */
> __u64 freepages_count;
> __u64 freepages_delay_total;
> + /* Per-task storage I/O accounting ends */
> +
> +#define TASKSTATS_HAS_LIMIT_ACCOUNTING
> + /* Per-task resource accounting starts */
> + __u64 resource_hiwater[RLIM_NLIMITS]; /* high-watermark of
> + RLIMIT
> + resources */
> + /* Per-task resource accounting ends */
> };
Why playing with version number? It complexifies the (userland) code and
existing applications break when the kernel is updated.
Goal of netlink is to be easily extensible. By adding a new attribute, existing
userspace tools won't break.
Regards,
Nicolas
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