Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753065Ab1F1TSY (ORCPT ); Tue, 28 Jun 2011 15:18:24 -0400 Received: from mail-pv0-f174.google.com ([74.125.83.174]:33934 "EHLO mail-pv0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750883Ab1F1TSS convert rfc822-to-8bit (ORCPT ); Tue, 28 Jun 2011 15:18:18 -0400 MIME-Version: 1.0 In-Reply-To: <1309244992-2305-10-git-send-email-jim.cromie@gmail.com> References: <1309244992-2305-1-git-send-email-jim.cromie@gmail.com> <1309244992-2305-10-git-send-email-jim.cromie@gmail.com> From: Jim Cromie Date: Tue, 28 Jun 2011 13:17:48 -0600 Message-ID: Subject: Re: [PATCH 09/11] dynamic_debug: add_to_pending() saves non-matching queries for later. To: linux-kernel@vger.kernel.org Cc: gnb@fmeh.org, jbaron@redhat.com, bvanassche@acm.org, gregkh@suse.de, Jim Cromie Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3550 Lines: 93 On Tue, Jun 28, 2011 at 1:09 AM, Jim Cromie wrote: > When a query/rule doesnt match, call add_to_pending(new function) > to copy the query off the stack, into a (new) struct pending_query, > and add to pending_queries (new) list. > > Patch adds: /sys/module/dynamic_debug/parameters/ > ?verbose - rw, added previously, here for completeness > ?pending_ct - ro, shows current count of pending queries > ?pending_max - rw, set max pending, further pending queries are rejected > > With this and previous patches, queries added on the boot-line which > do not match (because module is not built-in, and thus not present yet) > are added to pending_queries. > > IE, with these boot-line additions: > ?dynamic_debug.verbose=1 ddebug_query="module scx200_hrt +p" > > Kernel will log the following: > > ddebug_exec_queries: query 0: "module scx200_hrt +p" > ddebug_tokenize: split into words: "module" "scx200_hrt" "+p" > ddebug_parse_query: parsed q->function="(null)" q->filename="(null)" q->module="scx200_hrt" q->format="(null)" q->lineno=0-0 > ddebug_parse_flags: op='+' > ddebug_parse_flags: flags=0x1 > ddebug_parse_flags: *flagsp=0x1 *maskp=0xffffffff > ddebug_exec_query: nfound 0 on q->function="(null)" q->filename="(null)" q->module="scx200_hrt" q->format="(null)" q->lineno=0-0 > ddebug_add_to_pending: add to pending: q->function="(null)" q->filename="(null)" q->module="scx200_hrt" q->format="(null)" q->lineno=0-0 > ddebug_add_to_pending: ddebug: query saved as pending 1 > > Signed-off-by: Jim Cromie > --- > ?lib/dynamic_debug.c | ? 78 +++++++++++++++++++++++++++++++++++++++++++++++---- > ?1 files changed, 72 insertions(+), 6 deletions(-) > > diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c > index 9b8b1e8..37d0275 100644 > --- a/lib/dynamic_debug.c > +++ b/lib/dynamic_debug.c > @@ -53,6 +53,16 @@ struct ddebug_query { > ? ? ? ?unsigned int first_lineno, last_lineno; > ?}; > > +struct pending_query { > + ? ? ? struct list_head link; > + ? ? ? struct ddebug_query query; > + ? ? ? char filename[100]; > + ? ? ? char module[30]; > + ? ? ? char function[50]; > + ? ? ? char format[200]; > + ? ? ? unsigned int flags, mask; > +}; > + > ?struct ddebug_iter { > ? ? ? ?struct ddebug_table *table; > ? ? ? ?unsigned int idx; > @@ -61,7 +71,13 @@ struct ddebug_iter { > ?static DEFINE_MUTEX(ddebug_lock); > ?static LIST_HEAD(ddebug_tables); > ?static int verbose = 0; > -module_param(verbose, int, 0744); > +module_param(verbose, int, 0644); > + > +/* legal but inapplicable queries, save and test against new modules */ > +static LIST_HEAD(pending_queries); > +static int pending_ct, pending_max = 100; > +module_param(pending_ct, int, 0444); > +module_param(pending_max, int, 0644); > > ?/* Return the last part of a pathname */ > ?static inline const char *basename(const char *path) > @@ -96,6 +112,56 @@ static char *ddebug_describe_flags(struct _ddebug *dp, char *buf, > ? ? ? ?return buf; > ?} > > +static char prbuf_query[300]; > + > +static char *show_ddebug_query(const struct ddebug_query *q) > +{ this part (the static fixed-length var) gives me some heartburn. I almost went with macros using pr_info to replace the 2 show_*_query fns, but a