From: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
To: Petr Mladek <pmladek@suse.com>
Cc: John Ogness <john.ogness@linutronix.de>,
lijiang <lijiang@redhat.com>,
Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
Peter Zijlstra <peterz@infradead.org>,
Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
Steven Rostedt <rostedt@goodmis.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Andrea Parri <parri.andrea@gmail.com>,
Thomas Gleixner <tglx@linutronix.de>,
kexec@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 0/2] printk: replace ringbuffer
Date: Fri, 14 Feb 2020 10:07:55 +0900 [thread overview]
Message-ID: <20200214010755.GA13877@google.com> (raw)
In-Reply-To: <20200213130720.j4e5qv37am2bapup@pathway.suse.cz>
On (20/02/13 14:07), Petr Mladek wrote:
> On Wed 2020-02-05 17:12:12, John Ogness wrote:
> > On 2020-02-05, lijiang <lijiang@redhat.com> wrote:
> > > Do you have any suggestions about the size of CONFIG_LOG_* and
> > > CONFIG_PRINTK_* options by default?
> >
> > The new printk implementation consumes more than double the memory that
> > the current printk implementation requires. This is because dictionaries
> > and meta-data are now stored separately.
> >
> > If the old defaults (LOG_BUF_SHIFT=17 LOG_CPU_MAX_BUF_SHIFT=12) were
> > chosen because they are maximally acceptable defaults, then the defaults
> > should be reduced by 1 so that the final size is "similar" to the
> > current implementation.
> >
> > If instead the defaults are left as-is, a machine with less than 64 CPUs
> > will reserve 336KiB for printk information (128KiB text, 128KiB
> > dictionary, 80KiB meta-data).
> >
> > It might also be desirable to reduce the dictionary size (maybe 1/4 the
> > size of text?).
>
> Good questions. It would be great to check the usage on some real
> systems.
[..]
> I wish the dictionaries were never added ;-) They complicate the code
> and nobody knows how many people actually use the information.
Maybe we can have CONFIG_PRINTK_EXTRA_PAYLOAD [for dicts] so people can
compile it out if it's not needed. This can save several bytes here and
there.
-ss
next prev parent reply other threads:[~2020-02-14 1:07 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-28 16:19 [PATCH 0/2] printk: replace ringbuffer John Ogness
2020-01-28 16:19 ` [PATCH 1/2] printk: add lockless buffer John Ogness
2020-01-29 3:53 ` Steven Rostedt
2020-02-21 11:54 ` more barriers: " Petr Mladek
2020-02-27 12:04 ` John Ogness
2020-03-04 15:08 ` Petr Mladek
2020-03-13 10:13 ` John Ogness
2020-02-21 12:05 ` misc nits " Petr Mladek
2020-03-02 10:38 ` John Ogness
2020-03-02 12:17 ` Joe Perches
2020-03-02 12:32 ` Petr Mladek
2020-03-02 13:43 ` John Ogness
2020-03-03 9:47 ` Petr Mladek
2020-03-03 15:42 ` John Ogness
2020-03-04 10:09 ` Petr Mladek
2020-03-04 9:40 ` Petr Mladek
2020-01-28 16:19 ` [PATCH 2/2] printk: use the lockless ringbuffer John Ogness
2020-02-13 9:07 ` Sergey Senozhatsky
2020-02-13 9:42 ` John Ogness
2020-02-13 11:59 ` Sergey Senozhatsky
2020-02-13 22:36 ` John Ogness
2020-02-14 1:41 ` Sergey Senozhatsky
2020-02-14 2:09 ` Sergey Senozhatsky
2020-02-14 9:48 ` John Ogness
2020-02-14 13:29 ` lijiang
2020-02-14 13:50 ` John Ogness
2020-02-15 4:15 ` lijiang
2020-02-17 15:40 ` crashdump: " Petr Mladek
2020-02-17 16:14 ` John Ogness
2020-02-17 14:41 ` misc details: " Petr Mladek
2020-02-25 20:11 ` John Ogness
2020-02-26 9:54 ` Petr Mladek
2020-02-05 4:25 ` [PATCH 0/2] printk: replace ringbuffer lijiang
2020-02-05 4:42 ` Sergey Senozhatsky
2020-02-05 4:48 ` Sergey Senozhatsky
2020-02-05 5:02 ` Sergey Senozhatsky
2020-02-05 5:38 ` lijiang
2020-02-05 6:36 ` Sergey Senozhatsky
2020-02-05 9:00 ` John Ogness
2020-02-05 9:28 ` Sergey Senozhatsky
2020-02-05 10:19 ` lijiang
2020-02-05 16:12 ` John Ogness
2020-02-06 9:12 ` lijiang
2020-02-13 13:07 ` Petr Mladek
2020-02-14 1:07 ` Sergey Senozhatsky [this message]
2020-02-05 11:07 ` Sergey Senozhatsky
2020-02-05 15:48 ` John Ogness
2020-02-05 19:29 ` Joe Perches
2020-02-06 6:31 ` Sergey Senozhatsky
2020-02-06 7:30 ` lijiang
2020-02-07 1:40 ` Steven Rostedt
2020-02-07 7:43 ` John Ogness
2020-02-14 15:56 ` Petr Mladek
2020-02-17 11:13 ` John Ogness
2020-02-17 14:50 ` Petr Mladek
2020-02-25 19:27 ` John Ogness
2020-02-05 9:36 ` lijiang
2020-02-06 9:21 ` lijiang
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