From 5f97a5a8799b8d7d0afdb9d68a50a4e0e8298a05 Mon Sep 17 00:00:00 2001 From: Dave Young Date: Tue, 29 Apr 2008 00:59:43 -0700 Subject: 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 Acked-by: Paul E. McKenney Tested-by: Paul E. McKenney Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/Makefile | 2 +- lib/ratelimit.c | 51 +++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 52 insertions(+), 1 deletion(-) create mode 100644 lib/ratelimit.c (limited to 'lib') diff --git a/lib/Makefile b/lib/Makefile index 2d7001b7f5a4..0ae4eb047aac 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -6,7 +6,7 @@ lib-y := ctype.o string.o vsprintf.o cmdline.o \ rbtree.o radix-tree.o dump_stack.o \ idr.o int_sqrt.o extable.o prio_tree.o \ sha1.o irq_regs.o reciprocal_div.o argv_split.o \ - proportions.o prio_heap.o + proportions.o prio_heap.o ratelimit.o lib-$(CONFIG_MMU) += ioremap.o lib-$(CONFIG_SMP) += cpumask.o diff --git a/lib/ratelimit.c b/lib/ratelimit.c new file mode 100644 index 000000000000..485e3040dcd4 --- /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 + * + * This file is released under the GPLv2. + * + */ + +#include +#include +#include + +/* + * __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); -- cgit v1.2.3