Pollers are meant to be running for a short duration. A poller that runs longer than 20 milliseconds probably deserves a closer look.
Let's print a one time warning in this case and have the poller command output report how many times the condition occurred. Signed-off-by: Ahmad Fatoum <[email protected]> --- common/poller.c | 35 ++++++++++++++++++++++++++++++++--- include/poller.h | 3 ++- 2 files changed, 34 insertions(+), 4 deletions(-) diff --git a/common/poller.c b/common/poller.c index 0409d3cf8111..77d93ae8ccdf 100644 --- a/common/poller.c +++ b/common/poller.c @@ -3,6 +3,8 @@ * Copyright (C) 2010 Marc Kleine-Budde <[email protected]> */ +#define pr_fmt(fmt) "poller: " fmt + #include <common.h> #include <driver.h> #include <malloc.h> @@ -10,6 +12,13 @@ #include <param.h> #include <poller.h> #include <clock.h> +#include <linux/ktime.h> + +/* + * Pollers are meant to poll and quickly execute actions. + * Exceeding the maximum runtime below triggers a one-time warning. + */ +#define POLLER_MAX_RUNTIME_MS 20 static LIST_HEAD(poller_list); static int __poller_active; @@ -116,9 +125,23 @@ void poller_call(void) __poller_active = 1; - list_for_each_entry_safe(poller, tmp, &poller_list, list) + list_for_each_entry_safe(poller, tmp, &poller_list, list) { + ktime_t start = ktime_get(); + s64 duration_ms; + poller->func(poller); + duration_ms = ktime_ms_delta(ktime_get(), start); + if (duration_ms > POLLER_MAX_RUNTIME_MS) { + if (!poller->overtime) + pr_warn("'%s' took unexpectedly long: %llums\n", + poller->name, duration_ms); + + if (poller->overtime < U16_MAX) + poller->overtime++; + } + } + __poller_active = 0; } @@ -155,8 +178,14 @@ static void poller_info(void) return; } - list_for_each_entry(poller, &poller_list, list) - printf("%s\n", poller->name); + list_for_each_entry(poller, &poller_list, list) { + printf("%s", poller->name); + if (poller->overtime) + printf(": overtime %s%u", + poller->overtime == U16_MAX ? ">= " : "", + poller->overtime); + printf("\n"); + } } BAREBOX_CMD_HELP_START(poller) diff --git a/include/poller.h b/include/poller.h index 6e51a0613356..31db907ba5b8 100644 --- a/include/poller.h +++ b/include/poller.h @@ -11,7 +11,8 @@ struct poller_struct { void (*func)(struct poller_struct *poller); - int registered; + u16 registered:1; + u16 overtime; struct list_head list; char *name; }; -- 2.39.2
