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author | Dave Young <hidave.darkstar@gmail.com> | 2008-04-29 00:59:43 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-04-29 08:06:06 -0700 |
commit | 5f97a5a8799b8d7d0afdb9d68a50a4e0e8298a05 (patch) | |
tree | 03f0a35e50e9a765603fc9249e601b52e043fd0d /lib/ratelimit.c | |
parent | 762873c251b056c6c1b29e83a4dabafb064e5421 (diff) | |
download | kernel_goldelico_gta04-5f97a5a8799b8d7d0afdb9d68a50a4e0e8298a05.zip kernel_goldelico_gta04-5f97a5a8799b8d7d0afdb9d68a50a4e0e8298a05.tar.gz kernel_goldelico_gta04-5f97a5a8799b8d7d0afdb9d68a50a4e0e8298a05.tar.bz2 |
isolate ratelimit from printk.c for other use
Due to the rcupreempt.h WARN_ON trigged, I got 2G syslog file. For some
serious complaining of kernel, we need repeat the warnings, so here I isolate
the ratelimit part of printk.c to a standalone file.
Signed-off-by: Dave Young <hidave.darkstar@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib/ratelimit.c')
-rw-r--r-- | lib/ratelimit.c | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/lib/ratelimit.c b/lib/ratelimit.c new file mode 100644 index 0000000..485e304 --- /dev/null +++ b/lib/ratelimit.c @@ -0,0 +1,51 @@ +/* + * ratelimit.c - Do something with rate limit. + * + * Isolated from kernel/printk.c by Dave Young <hidave.darkstar@gmail.com> + * + * This file is released under the GPLv2. + * + */ + +#include <linux/kernel.h> +#include <linux/jiffies.h> +#include <linux/module.h> + +/* + * __ratelimit - rate limiting + * @ratelimit_jiffies: minimum time in jiffies between two callbacks + * @ratelimit_burst: number of callbacks we do before ratelimiting + * + * This enforces a rate limit: not more than @ratelimit_burst callbacks + * in every ratelimit_jiffies + */ +int __ratelimit(int ratelimit_jiffies, int ratelimit_burst) +{ + static DEFINE_SPINLOCK(ratelimit_lock); + static unsigned toks = 10 * 5 * HZ; + static unsigned long last_msg; + static int missed; + unsigned long flags; + unsigned long now = jiffies; + + spin_lock_irqsave(&ratelimit_lock, flags); + toks += now - last_msg; + last_msg = now; + if (toks > (ratelimit_burst * ratelimit_jiffies)) + toks = ratelimit_burst * ratelimit_jiffies; + if (toks >= ratelimit_jiffies) { + int lost = missed; + + missed = 0; + toks -= ratelimit_jiffies; + spin_unlock_irqrestore(&ratelimit_lock, flags); + if (lost) + printk(KERN_WARNING "%s: %d messages suppressed\n", + __func__, lost); + return 1; + } + missed++; + spin_unlock_irqrestore(&ratelimit_lock, flags); + return 0; +} +EXPORT_SYMBOL(__ratelimit); |