Re: [PATCH 1/8] isdn/gigaset: ratelimit CAPI message dumps
From: Karsten Keil <hidden>
Date: 2012-04-26 06:52:05
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Am 26.04.2012 01:02, schrieb Tilman Schmidt:
Introduce a global ratelimit for CAPI message dumps to protect against possible log flood. Drop the ratelimit for ignored messages which is now covered by the global one.
Hmm, I think the only CAPI messages which would need a ratelimit are related to the DATA_B3 messages. If you need CAPI debug messages in most cases you do not need all of the DATA_B3, but you do not want to miss any other message related to the call control. With a general rate limit you do not have the control, which messages are logged and which are not. And here maybe some cases, when even the DATA_B3 are important (e.g. searching bugs in flow control), so I would make it still conditional to allow to print all messages. And I'm not sure, if this is really something for stable.
quoted hunk ↗ jump to hunk
Signed-off-by: Tilman Schmidt <redacted> CC: stable <stable@kernel.org> --- drivers/isdn/gigaset/capi.c | 22 +++++++++------------- 1 files changed, 9 insertions(+), 13 deletions(-)diff --git a/drivers/isdn/gigaset/capi.c b/drivers/isdn/gigaset/capi.c index 343b5c8..292ca2f 100644 --- a/drivers/isdn/gigaset/capi.c +++ b/drivers/isdn/gigaset/capi.c@@ -14,6 +14,7 @@ #include "gigaset.h" #include <linux/proc_fs.h> #include <linux/seq_file.h> +#include <linux/ratelimit.h> #include <linux/isdn/capilli.h> #include <linux/isdn/capicmd.h> #include <linux/isdn/capiutil.h>@@ -223,10 +224,14 @@ get_appl(struct gigaset_capi_ctr *iif, u16 appl) static inline void dump_cmsg(enum debuglevel level, const char *tag, _cmsg *p) { #ifdef CONFIG_GIGASET_DEBUG + /* dump at most 20 messages in 20 secs */ + static DEFINE_RATELIMIT_STATE(msg_dump_ratelimit, 20 * HZ, 20); _cdebbuf *cdb; if (!(gigaset_debuglevel & level)) return; + if (!___ratelimit(&msg_dump_ratelimit, tag)) + return; cdb = capi_cmsg2str(p); if (cdb) {@@ -2059,12 +2064,6 @@ static void do_reset_b3_req(struct gigaset_capi_ctr *iif, } /* - * dump unsupported/ignored messages at most twice per minute, - * some apps send those very frequently - */ -static unsigned long ignored_msg_dump_time; - -/* * unsupported CAPI message handler */ static void do_unsupported(struct gigaset_capi_ctr *iif,@@ -2073,8 +2072,7 @@ static void do_unsupported(struct gigaset_capi_ctr *iif, { /* decode message */ capi_message2cmsg(&iif->acmsg, skb->data); - if (printk_timed_ratelimit(&ignored_msg_dump_time, 30 * 1000)) - dump_cmsg(DEBUG_CMD, __func__, &iif->acmsg); + dump_cmsg(DEBUG_CMD, __func__, &iif->acmsg); send_conf(iif, ap, skb, CapiMessageNotSupportedInCurrentState); }@@ -2085,11 +2083,9 @@ static void do_nothing(struct gigaset_capi_ctr *iif, struct gigaset_capi_appl *ap, struct sk_buff *skb) { - if (printk_timed_ratelimit(&ignored_msg_dump_time, 30 * 1000)) { - /* decode message */ - capi_message2cmsg(&iif->acmsg, skb->data); - dump_cmsg(DEBUG_CMD, __func__, &iif->acmsg); - } + /* decode message */ + capi_message2cmsg(&iif->acmsg, skb->data); + dump_cmsg(DEBUG_CMD, __func__, &iif->acmsg); dev_kfree_skb_any(skb); }
-- Karsten Keil Linux Kernel Development Tel: +49 175 7249132 Mail: keil@b1-systems.de B1 Systems GmbH Osterfeldstraße 7 / 85088 Vohburg / http://www.b1-systems.de GF: Ralph Dehner / Unternehmenssitz: Vohburg / AG: Ingolstadt,HRB 3537