Re: [PATCH v4] sched: automated per session task groups

Ingo Molnar
2010-11-30T14:13:38Z

* Mike Galbraith <efault@gmx.de> wrote:

> On Mon, 2010-11-29 at 20:23 -0800, Paul Turner wrote:
>
> > I've left some machines running tip + fix above + autogroup to see if
> > anything else emerges. Hasn't crashed yet, I'll leave it going
> > overnight.
>
> Thanks. Below is the hopefully final version against tip. The last I
> sent contained a couple remnants.

Note, I removed this chunk:

> kernel/sched_debug.c | 29 ++--

> Index: linux-2.6/kernel/sched_debug.c
> ===================================================================
> --- linux-2.6.orig/kernel/sched_debug.c
> +++ linux-2.6/kernel/sched_debug.c
> @@ -87,6 +87,20 @@ static void print_cfs_group_stats(struct
> }
> #endif
>
> +#if defined(CONFIG_CGROUP_SCHED) && \
> + (defined(CONFIG_FAIR_GROUP_SCHED) || defined(CONFIG_RT_GROUP_SCHED))
> +static void task_group_path(struct task_group *tg, char *buf, int buflen)
> +{
> + /* may be NULL if the underlying cgroup isn't fully-created yet */
> + if (!tg->css.cgroup) {
> + if (!autogroup_path(tg, buf, buflen))
> + buf[0] = '\0';
> + return;
> + }
> + cgroup_path(tg->css.cgroup, buf, buflen);
> +}
> +#endif
> +
> static void
> print_task(struct seq_file *m, struct rq *rq, struct task_struct *p)
> {
> @@ -115,7 +129,7 @@ print_task(struct seq_file *m, struct rq
> char path[64];
>
> rcu_read_lock();
> - cgroup_path(task_group(p)->css.cgroup, path, sizeof(path));
> + task_group_path(task_group(p), path, sizeof(path));
> rcu_read_unlock();
> SEQ_printf(m, " %s", path);
> }
> @@ -147,19 +161,6 @@ static void print_rq(struct seq_file *m,
> read_unlock_irqrestore(&tasklist_lock, flags);
> }
>
> -#if defined(CONFIG_CGROUP_SCHED) && \
> - (defined(CONFIG_FAIR_GROUP_SCHED) || defined(CONFIG_RT_GROUP_SCHED))
> -static void task_group_path(struct task_group *tg, char *buf, int buflen)
> -{
> - /* may be NULL if the underlying cgroup isn't fully-created yet */
> - if (!tg->css.cgroup) {
> - buf[0] = '\0';
> - return;
> - }
> - cgroup_path(tg->css.cgroup, buf, buflen);
> -}
> -#endif
> -
> void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
> {
> s64 MIN_vruntime = -1, min_vruntime, max_vruntime = -1,

Because it didn't build (for obvious reasons - the CONFIG conditions dont match up),
but more importantly it's quite ugly. Some existing 'path' variables are 64 byte,
some are 128 byte - so there's pre-existing damage - i removed it all.

Could we do this debugging code in a bit saner way please? (as a delta patch on top
of the -tip that i'll push out in the next hour or so.)

Thanks,

Ingo