diff options
Diffstat (limited to 'debian/patches-rt/0250-watchdog-prevent-deferral-of-watchdogd-wakeup-on-RT.patch')
| -rw-r--r-- | debian/patches-rt/0250-watchdog-prevent-deferral-of-watchdogd-wakeup-on-RT.patch | 81 |
1 files changed, 0 insertions, 81 deletions
diff --git a/debian/patches-rt/0250-watchdog-prevent-deferral-of-watchdogd-wakeup-on-RT.patch b/debian/patches-rt/0250-watchdog-prevent-deferral-of-watchdogd-wakeup-on-RT.patch deleted file mode 100644 index c9d461226..000000000 --- a/debian/patches-rt/0250-watchdog-prevent-deferral-of-watchdogd-wakeup-on-RT.patch +++ /dev/null @@ -1,81 +0,0 @@ -From 2536bb24992f08158455b5ad1434f439f6543db5 Mon Sep 17 00:00:00 2001 -From: Julia Cartwright <julia@ni.com> -Date: Fri, 28 Sep 2018 21:03:51 +0000 -Subject: [PATCH 250/347] watchdog: prevent deferral of watchdogd wakeup on RT -Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patches-4.19.246-rt110.tar.xz - -When PREEMPT_RT_FULL is enabled, all hrtimer expiry functions are -deferred for execution into the context of ktimersoftd unless otherwise -annotated. - -Deferring the expiry of the hrtimer used by the watchdog core, however, -is a waste, as the callback does nothing but queue a kthread work item -and wakeup watchdogd. - -It's worst then that, too: the deferral through ktimersoftd also means -that for correct behavior a user must adjust the scheduling parameters -of both watchdogd _and_ ktimersoftd, which is unnecessary and has other -side effects (like causing unrelated expiry functions to execute at -potentially elevated priority). - -Instead, mark the hrtimer used by the watchdog core as being _HARD to -allow it's execution directly from hardirq context. The work done in -this expiry function is well-bounded and minimal. - -A user still must adjust the scheduling parameters of the watchdogd -to be correct w.r.t. their application needs. - -Cc: Guenter Roeck <linux@roeck-us.net> -Reported-and-tested-by: Steffen Trumtrar <s.trumtrar@pengutronix.de> -Reported-by: Tim Sander <tim@krieglstein.org> -Signed-off-by: Julia Cartwright <julia@ni.com> -Acked-by: Guenter Roeck <linux@roeck-us.net> -[bigeasy: use only HRTIMER_MODE_REL_HARD] -Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> ---- - drivers/watchdog/watchdog_dev.c | 8 ++++---- - 1 file changed, 4 insertions(+), 4 deletions(-) - -diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c -index 8fe59b7d8eec..516782cff8d2 100644 ---- a/drivers/watchdog/watchdog_dev.c -+++ b/drivers/watchdog/watchdog_dev.c -@@ -145,7 +145,7 @@ static inline void watchdog_update_worker(struct watchdog_device *wdd) - ktime_t t = watchdog_next_keepalive(wdd); - - if (t > 0) -- hrtimer_start(&wd_data->timer, t, HRTIMER_MODE_REL); -+ hrtimer_start(&wd_data->timer, t, HRTIMER_MODE_REL_HARD); - } else { - hrtimer_cancel(&wd_data->timer); - } -@@ -164,7 +164,7 @@ static int __watchdog_ping(struct watchdog_device *wdd) - if (ktime_after(earliest_keepalive, now)) { - hrtimer_start(&wd_data->timer, - ktime_sub(earliest_keepalive, now), -- HRTIMER_MODE_REL); -+ HRTIMER_MODE_REL_HARD); - return 0; - } - -@@ -959,7 +959,7 @@ static int watchdog_cdev_register(struct watchdog_device *wdd) - dev_set_name(&wd_data->dev, "watchdog%d", wdd->id); - - kthread_init_work(&wd_data->work, watchdog_ping_work); -- hrtimer_init(&wd_data->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); -+ hrtimer_init(&wd_data->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD); - wd_data->timer.function = watchdog_timer_expired; - - if (wdd->id == 0) { -@@ -1007,7 +1007,7 @@ static int watchdog_cdev_register(struct watchdog_device *wdd) - __module_get(wdd->ops->owner); - get_device(&wd_data->dev); - if (handle_boot_enabled) -- hrtimer_start(&wd_data->timer, 0, HRTIMER_MODE_REL); -+ hrtimer_start(&wd_data->timer, 0, HRTIMER_MODE_REL_HARD); - else - pr_info("watchdog%d running and kernel based pre-userspace handler disabled\n", - wdd->id); --- -2.36.1 - |