On Mon, 4 Jul 2016 16:24:51 +0200
Borislav Petkov <b...@alien8.de> wrote:
> From: Borislav Petkov <b...@suse.de>
>
> Extend the ratelimiting facility to print the amount of suppressed lines
> when it is being released.
>
> Separated from a previous patch by Linus.
>
> Also, make the ON_RELEASE image not use "callbacks" as it is misleading.
>
> Signed-off-by: Borislav Petkov <b...@suse.de>
> Acked-by: Linus Torvalds <torva...@linux-foundation.org>
> Cc: Andrew Morton <a...@linux-foundation.org>
> Cc: Franck Bui <f...@suse.com>
> Cc: Greg Kroah-Hartman <gre...@linuxfoundation.org>
> Cc: Ingo Molnar <mi...@kernel.org>
> Cc: Linus Torvalds <torva...@linux-foundation.org>
> Cc: Peter Zijlstra <pet...@infradead.org>
> Cc: Steven Rostedt <rost...@goodmis.org>
> Cc: Uwe Kleine-König <u.kleine-koe...@pengutronix.de>
> ---
> include/linux/ratelimit.h | 36 +++++++++++++++++++++++++++++++-----
> lib/ratelimit.c | 6 ++++--
> 2 files changed, 35 insertions(+), 7 deletions(-)
>
> diff --git a/include/linux/ratelimit.h b/include/linux/ratelimit.h
> index 18102529254e..1d8a17ee8395 100644
> --- a/include/linux/ratelimit.h
> +++ b/include/linux/ratelimit.h
> @@ -2,11 +2,15 @@
> #define _LINUX_RATELIMIT_H
>
> #include <linux/param.h>
> +#include <linux/sched.h>
> #include <linux/spinlock.h>
>
> #define DEFAULT_RATELIMIT_INTERVAL (5 * HZ)
> #define DEFAULT_RATELIMIT_BURST 10
>
> +/* issue num suppressed message on exit */
> +#define RATELIMIT_MSG_ON_RELEASE BIT(0)
> +
> struct ratelimit_state {
> raw_spinlock_t lock; /* protect the state */
>
> @@ -15,6 +19,7 @@ struct ratelimit_state {
> int printed;
> int missed;
> unsigned long begin;
> + unsigned long flags;
> };
>
> #define RATELIMIT_STATE_INIT(name, interval_init, burst_init) {
> \
> @@ -34,12 +39,33 @@ struct ratelimit_state {
> static inline void ratelimit_state_init(struct ratelimit_state *rs,
> int interval, int burst)
> {
> + memset(rs, 0, sizeof(*rs));
> +
> raw_spin_lock_init(&rs->lock);
> - rs->interval = interval;
> - rs->burst = burst;
> - rs->printed = 0;
> - rs->missed = 0;
> - rs->begin = 0;
> + rs->interval = interval;
> + rs->burst = burst;
> +}
> +
> +static inline void ratelimit_default_init(struct ratelimit_state *rs)
> +{
> + return ratelimit_state_init(rs, DEFAULT_RATELIMIT_INTERVAL,
> + DEFAULT_RATELIMIT_BURST);
> +}
> +
> +static inline void ratelimit_state_exit(struct ratelimit_state *rs)
> +{
> + if (!(rs->flags & RATELIMIT_MSG_ON_RELEASE))
> + return;
> +
> + if (rs->missed)
> + printk(KERN_WARNING "%s: %d output lines suppressed due to
> ratelimiting\n",
> + current->comm, rs->missed);
Is the comm important? Maybe add the function that called it?
"%pS", _THIS_IP_
Perhaps add __always_inline, as _THIS_IP_ will point into the function
that calls this?
-- Steve
> +}
> +
> +static inline void
> +ratelimit_set_flags(struct ratelimit_state *rs, unsigned long flags)
> +{
> + rs->flags = flags;
> }
>
> extern struct ratelimit_state printk_ratelimit_state;
> diff --git a/lib/ratelimit.c b/lib/ratelimit.c
> index 2c5de86460c5..b753f0cfb00b 100644
> --- a/lib/ratelimit.c
> +++ b/lib/ratelimit.c
> @@ -46,12 +46,14 @@ int ___ratelimit(struct ratelimit_state *rs, const char
> *func)
> rs->begin = jiffies;
>
> if (time_is_before_jiffies(rs->begin + rs->interval)) {
> - if (rs->missed)
> + if (rs->missed && !(rs->flags & RATELIMIT_MSG_ON_RELEASE))
> printk(KERN_WARNING "%s: %d callbacks suppressed\n",
> func, rs->missed);
> rs->begin = jiffies;
> rs->printed = 0;
> - rs->missed = 0;
> +
> + if (!(rs->flags & RATELIMIT_MSG_ON_RELEASE))
> + rs->missed = 0;
> }
> if (rs->burst && rs->burst > rs->printed) {
> rs->printed++;
