Messages in this thread Patch in this message |  | | Date | Mon, 10 Mar 2008 14:31:15 +0800 | From | Dave Young <> | Subject | [PATCH RFC] [1/3] isolate ratelimit from printk.c for other use |
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This series include 3 patch, they need to be applied in order. 1) isolate ratelimit from printk.c 2) add WARN_ON_SECS macro 3) use WARN_ON_SECS macro in rcupreempt.h
Please give some comments and suggestions for improvement, thanks.
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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>
--- include/linux/kernel.h | 1 kernel/printk.c | 26 ------------------------ lib/Makefile | 2 - lib/ratelimit.c | 51 +++++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 54 insertions(+), 26 deletions(-)
diff -uprN linux/include/linux/kernel.h linux.new/include/linux/kernel.h --- linux/include/linux/kernel.h 2008-03-10 13:41:18.000000000 +0800 +++ linux.new/include/linux/kernel.h 2008-03-10 13:42:06.000000000 +0800 @@ -188,6 +188,7 @@ extern int log_buf_copy(char *dest, int extern int printk_ratelimit_jiffies; extern int printk_ratelimit_burst; extern int printk_ratelimit(void); +extern int __ratelimit(int ratelimit_jiffies, int ratelimit_burst); extern int __printk_ratelimit(int ratelimit_jiffies, int ratelimit_burst); extern bool printk_timed_ratelimit(unsigned long *caller_jiffies, unsigned int interval_msec); diff -uprN linux/kernel/printk.c linux.new/kernel/printk.c --- linux/kernel/printk.c 2008-03-10 13:41:37.000000000 +0800 +++ linux.new/kernel/printk.c 2008-03-10 13:42:19.000000000 +0800 @@ -1261,31 +1261,7 @@ void tty_write_message(struct tty_struct */ int __printk_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 "printk: %d messages suppressed.\n", lost); - return 1; - } - missed++; - spin_unlock_irqrestore(&ratelimit_lock, flags); - return 0; + return __ratelimit(ratelimit_jiffies, ratelimit_burst); } EXPORT_SYMBOL(__printk_ratelimit); diff -uprN linux/lib/Makefile linux.new/lib/Makefile --- linux/lib/Makefile 2008-03-10 13:43:57.000000000 +0800 +++ linux.new/lib/Makefile 2008-03-10 13:42:38.000000000 +0800 @@ -6,7 +6,7 @@ lib-y := ctype.o string.o vsprintf.o cmd 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 -uprN linux/lib/ratelimit.c linux.new/lib/ratelimit.c --- linux/lib/ratelimit.c 1970-01-01 07:00:00.000000000 +0700 +++ linux.new/lib/ratelimit.c 2008-03-10 13:42:46.000000000 +0800 @@ -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 too 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 "__ratelimit: %d messages" + " suppressed.\n", lost); + return 1; + } + missed++; + spin_unlock_irqrestore(&ratelimit_lock, flags); + return 0; +} +EXPORT_SYMBOL(__ratelimit);
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