| Message ID | 3fa0ea3a19a51ae2797a25e281763451ad8d2844.1395322529.git.viresh.kumar@linaro.org |
|---|---|
| State | New |
| Headers | show |
Viresh Kumar <viresh.kumar@linaro.org> writes: > migrate_timer() is called when a CPU goes down and its timers are required to be > migrated to some other CPU. Its the responsibility of the users of the timer to > remove it before control reaches to migrate_timers(). > > As these were the pinned timers, the best we can do is: don't migrate these and > report to the user as well. > > That's all this patch does. > > Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> > --- > kernel/timer.c | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > diff --git a/kernel/timer.c b/kernel/timer.c > index fec4ab4..a7f8b99 100644 > --- a/kernel/timer.c > +++ b/kernel/timer.c > @@ -1606,11 +1606,22 @@ static int init_timers_cpu(int cpu) > static void migrate_timer_list(struct tvec_base *new_base, struct list_head *head) > { > struct timer_list *timer; > + int is_pinned; > > while (!list_empty(head)) { > timer = list_first_entry(head, struct timer_list, entry); > /* We ignore the accounting on the dying cpu */ > detach_timer(timer, false); > + > + is_pinned = tbase_get_pinned(timer->base); > + > + /* Check if CPU still has pinned timers */ > + if (is_pinned) { > + pr_warn("%s: can't migrate pinned timer: %p, removing it\n", > + __func__, timer); printk message will be confusing: removing it from what? Kevin > + continue; > + } > + > timer_set_base(timer, new_base); > internal_add_timer(new_base, timer); > } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
On 31 March 2014 21:26, Kevin Hilman <khilman@linaro.org> wrote: > Viresh Kumar <viresh.kumar@linaro.org> writes: >> + if (is_pinned) { >> + pr_warn("%s: can't migrate pinned timer: %p, removing it\n", >> + __func__, timer); > > printk message will be confusing: removing it from what? Hmm.. So, I am looking to do two modifications here. Just need inputs if that would be the right thing to do: - do a WARN() here as these timers should have been already removed - change print to: "can't migrate pinned timer %p, deactivating timer" Looks fine? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Viresh Kumar <viresh.kumar@linaro.org> writes: > On 31 March 2014 21:26, Kevin Hilman <khilman@linaro.org> wrote: >> Viresh Kumar <viresh.kumar@linaro.org> writes: >>> + if (is_pinned) { >>> + pr_warn("%s: can't migrate pinned timer: %p, removing it\n", >>> + __func__, timer); >> >> printk message will be confusing: removing it from what? > > Hmm.. So, I am looking to do two modifications here. Just need inputs > if that would be the right thing to do: > > - do a WARN() here as these timers should have been already removed > - change print to: "can't migrate pinned timer %p, deactivating timer" > > Looks fine? Yes. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
diff --git a/kernel/timer.c b/kernel/timer.c index fec4ab4..a7f8b99 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -1606,11 +1606,22 @@ static int init_timers_cpu(int cpu) static void migrate_timer_list(struct tvec_base *new_base, struct list_head *head) { struct timer_list *timer; + int is_pinned; while (!list_empty(head)) { timer = list_first_entry(head, struct timer_list, entry); /* We ignore the accounting on the dying cpu */ detach_timer(timer, false); + + is_pinned = tbase_get_pinned(timer->base); + + /* Check if CPU still has pinned timers */ + if (is_pinned) { + pr_warn("%s: can't migrate pinned timer: %p, removing it\n", + __func__, timer); + continue; + } + timer_set_base(timer, new_base); internal_add_timer(new_base, timer); }
migrate_timer() is called when a CPU goes down and its timers are required to be migrated to some other CPU. Its the responsibility of the users of the timer to remove it before control reaches to migrate_timers(). As these were the pinned timers, the best we can do is: don't migrate these and report to the user as well. That's all this patch does. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> --- kernel/timer.c | 11 +++++++++++ 1 file changed, 11 insertions(+)