linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Petr Mladek <pmladek@suse.com>
To: Chris Down <chris@chrisdown.name>
Cc: linux-kernel@vger.kernel.org, Jessica Yu <jeyu@kernel.org>,
	Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
	John Ogness <john.ogness@linutronix.de>,
	Steven Rostedt <rostedt@goodmis.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Johannes Weiner <hannes@cmpxchg.org>,
	Kees Cook <keescook@chromium.org>,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	Rasmus Villemoes <linux@rasmusvillemoes.dk>,
	kernel-team@fb.com
Subject: Re: [PATCH v7 5/5] printk: index: Add indexing support to dev_printk
Date: Thu, 17 Jun 2021 12:02:31 +0200	[thread overview]
Message-ID: <YMsdtyJxuSzcfD3H@alley> (raw)
In-Reply-To: <959c7aed1017cb2c9de922e0a820d397e29c6a5a.1623775748.git.chris@chrisdown.name>

On Tue 2021-06-15 17:52:56, Chris Down wrote:
> While for most kinds of issues we have counters, tracepoints, or metrics
> with a stable interface which can reliably be used to indicate issues,
> in order to react to production issues quickly we sometimes need to work
> with the interface which most kernel developers naturally use when
> developing: printk, and printk-esques like dev_printk.
> 
> dev_printk is by far the most likely custom subsystem printk to benefit
> from the printk indexing infrastructure, since niche device issues
> brought about by production changes, firmware upgrades, and the like are
> one of the most common things that we need printk infrastructure's
> assistance to monitor.
> 
> Often these errors were never expected to practically manifest in
> reality, and exhibit in code without extensive (or any) metrics present.
> As such, there are typically very few options for issue detection
> available to those with large fleets at the time the incident happens,
> and we thus benefit strongly from monitoring netconsole in these
> instances.
> 
> As such, add the infrastructure for dev_printk to be indexed in the
> printk index. Even on a minimal kernel config, the coverage of the base
> kernel's printk index is significantly improved:
> 
> Before:
> 
>     [root@ktst ~]# wc -l /sys/kernel/debug/printk/index/vmlinux
>     4497 /sys/kernel/debug/printk/index/vmlinux
> 
> After:
> 
>     [root@ktst ~]# wc -l /sys/kernel/debug/printk/index/vmlinux
>     5573 /sys/kernel/debug/printk/index/vmlinux
> 
> In terms of implementation, in order to trivially disambiguate them,
> dev_printk is now a macro which wraps _dev_printk.
> 
> Signed-off-by: Chris Down <chris@chrisdown.name>

Reviewed-by: Petr Mladek <pmladek@suse.com>
Tested-by: Petr Mladek <pmladek@suse.com>

Best Regards,
Petr

  reply	other threads:[~2021-06-17 10:02 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-15 16:52 [PATCH v7 0/5] printk: Userspace format indexing support Chris Down
2021-06-15 16:52 ` [PATCH v7 1/5] string_helpers: Escape double quotes in escape_special Chris Down
2021-06-15 21:42   ` Andy Shevchenko
2021-06-16  0:00     ` Chris Down
2021-06-16  2:05       ` Randy Dunlap
2021-06-16  8:08         ` Andy Shevchenko
2021-06-16 13:30           ` Steven Rostedt
2021-06-15 16:52 ` [PATCH v7 2/5] printk: Straighten out log_flags into printk_info_flags Chris Down
2021-06-15 16:52 ` [PATCH v7 3/5] printk: Rework parse_prefix into printk_parse_prefix Chris Down
2021-06-17  8:02   ` Petr Mladek
2021-06-15 16:52 ` [PATCH v7 4/5] printk: Userspace format indexing support Chris Down
2021-06-17  7:36   ` kernel test robot
2021-06-17  8:38     ` Andy Shevchenko
2021-06-17  9:39       ` Petr Mladek
2021-06-17 11:57       ` Chris Down
2021-06-17  9:43   ` Petr Mladek
2021-06-18 11:48   ` kernel test robot
2021-06-18 12:19     ` Chris Down
2021-06-18 15:00       ` Petr Mladek
2021-06-15 16:52 ` [PATCH v7 5/5] printk: index: Add indexing support to dev_printk Chris Down
2021-06-17 10:02   ` Petr Mladek [this message]
2021-06-17 10:10 ` [PATCH v7 0/5] printk: Userspace format indexing support Petr Mladek
2021-06-17 12:33   ` Andy Shevchenko
2021-06-17 14:50     ` Chris Down
2021-06-17 14:52       ` Chris Down
2021-06-17 12:36   ` Jessica Yu
2021-06-21  8:54   ` Petr Mladek
2021-06-23 21:08     ` Andrew Morton
2021-06-25  9:35       ` Petr Mladek
2021-07-19 13:06         ` Petr Mladek
2021-07-19 13:08           ` Petr Mladek

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=YMsdtyJxuSzcfD3H@alley \
    --to=pmladek@suse.com \
    --cc=andriy.shevchenko@linux.intel.com \
    --cc=chris@chrisdown.name \
    --cc=gregkh@linuxfoundation.org \
    --cc=hannes@cmpxchg.org \
    --cc=jeyu@kernel.org \
    --cc=john.ogness@linutronix.de \
    --cc=keescook@chromium.org \
    --cc=kernel-team@fb.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux@rasmusvillemoes.dk \
    --cc=rostedt@goodmis.org \
    --cc=sergey.senozhatsky@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).