mirrors/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2025-11-04 02:30:34 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions

ratelimit: extend to print suppressed messages on release

Browse source 
Extend the ratelimiting facility to print the amount of suppressed lines
when it is being released.

This use case is aimed at short-termed, burst-like users for which we
want to output the suppressed lines stats only once, after it has been
disposed of.  For an example, see /dev/kmsg usage in a follow-on patch.

Also, change the printk() line we issue on release to not use
"callbacks" as it is misleading: we're not suppressing callbacks but
printk() calls.

This has been separated from a previous patch by Linus.

Link: http://lkml.kernel.org/r/20160716061745.15795-2-bp@alien8.de
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Dave Young <dyoung@redhat.com>
Cc: Franck Bui <fbui@suse.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Borislav Petkov 2016-08-02 14:04:04 -07:00 committed by Linus Torvalds
parent b5644a153d
commit 6b1d174b0c
2 changed files with 39 additions and 9 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

38
include/linux/ratelimit.h
View file

@ -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 +39,35 @@ 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) {
pr_warn("%s: %d output lines suppressed due to ratelimiting\n",
current->comm, rs->missed);
rs->missed = 0;
}
}
static inline void
ratelimit_set_flags(struct ratelimit_state *rs, unsigned long flags)
{
rs->flags = flags;
}
extern struct ratelimit_state printk_ratelimit_state;

10
lib/ratelimit.c
View file

@ -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)
printk(KERN_WARNING "%s: %d callbacks suppressed\n",
func, rs->missed);
if (rs->missed) {
if (!(rs->flags & RATELIMIT_MSG_ON_RELEASE)) {
pr_warn("%s: %d callbacks suppressed\n", func, rs->missed);
rs->missed = 0;
}
}
rs->begin = jiffies;
rs->printed = 0;
rs->missed = 0;
}
if (rs->burst && rs->burst > rs->printed) {
rs->printed++;