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
next prev parent reply other threads:[~2021-06-17 10:02 UTC|newest]
Thread overview: 38+ 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 7:36 ` kernel test robot
2021-06-17 8:38 ` Andy Shevchenko
2021-06-17 8:38 ` Andy Shevchenko
2021-06-17 9:39 ` Petr Mladek
2021-06-17 9:39 ` Petr Mladek
2021-06-17 11:57 ` Chris Down
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 11:48 ` kernel test robot
2021-06-18 12:19 ` Chris Down
2021-06-18 12:19 ` Chris Down
2021-06-18 15:00 ` Petr Mladek
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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.