From: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
To: Sebastian Siewior <bigeasy@linutronix.de>
Cc: John Ogness <john.ogness@linutronix.de>,
Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
Petr Mladek <pmladek@suse.com>,
linux-kernel@vger.kernel.org,
Peter Zijlstra <peterz@infradead.org>,
Steven Rostedt <rostedt@goodmis.org>,
Daniel Wang <wonderfly@google.com>,
Andrew Morton <akpm@linux-foundation.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Alan Cox <gnomes@lxorguk.ukuu.org.uk>,
Jiri Slaby <jslaby@suse.com>, Peter Feiner <pfeiner@google.com>,
linux-serial@vger.kernel.org,
Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Subject: Re: [RFC PATCH v1 00/25] printk: new implementation
Date: Wed, 13 Mar 2019 18:27:59 +0900 [thread overview]
Message-ID: <20190313092759.GA10060@jagdpanzerIV> (raw)
In-Reply-To: <20190313084028.f2m4qhxd5sjzzawr@linutronix.de>
On (03/13/19 09:40), Sebastian Siewior wrote:
> On 2019-03-13 09:19:32 [+0100], John Ogness wrote:
> > recursive situation. As you are pointing out, the notification/wake
> > component of printk_safe will still be needed. I will leave that (small)
> > part in printk_safe.c.
>
> Does this mean we keep irq_work part or we bury it and solve it by other
> means?
That's a very good question. Because if we add console_trylock()
to printk(), then we can't invoke ->atomic() consoles when console_sem
is already locked, because one of the registered drivers is currently
being modified by a 3rd party and printk(), thus, must stay away.
Once that modification will be done console_unlock() will print all
pending messages. This is current design. And this conflicts with the
whole idea of ->atomic() consoles.
So may be we need a whole new scheme in this department as well.
For instance [*and this is completely untested idea* !!!]
*May be* we can take a closer look and find cases when ->atomic
consoles don't really depend on console_sem. And *may be* we can
split the console drivers list and somehow forbid removal and
modification (ioctl) of ->atomic consoles under us. Assuming that
this is doable we then can start iterating ->atomic consoles list
with unlocked console_sem.
Non->atomic consoles or consoles which depend on console_sem (VT,
fbcon and so on) will stay in another list, and we will take
console_sem before we iterate that list and invoke those drivers.
One more time - a completely random thought.
-ss
next prev parent reply other threads:[~2019-03-13 9:27 UTC|newest]
Thread overview: 149+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-12 14:29 [RFC PATCH v1 00/25] printk: new implementation John Ogness
2019-02-12 14:29 ` [RFC PATCH v1 01/25] printk-rb: add printk ring buffer documentation John Ogness
2019-02-12 14:45 ` Greg Kroah-Hartman
2019-02-12 14:29 ` [RFC PATCH v1 02/25] printk-rb: add prb locking functions John Ogness
2019-02-13 15:45 ` Petr Mladek
2019-02-13 21:39 ` John Ogness
2019-02-14 10:33 ` Petr Mladek
2019-02-14 12:10 ` John Ogness
2019-02-15 10:26 ` Petr Mladek
2019-02-15 10:56 ` John Ogness
2019-03-07 2:12 ` Sergey Senozhatsky
2019-02-12 14:29 ` [RFC PATCH v1 03/25] printk-rb: define ring buffer struct and initializer John Ogness
2019-02-12 14:46 ` Greg Kroah-Hartman
2019-02-14 12:46 ` Petr Mladek
2019-02-12 14:29 ` [RFC PATCH v1 04/25] printk-rb: add writer interface John Ogness
2019-02-14 15:16 ` Petr Mladek
2019-02-14 23:36 ` John Ogness
2019-02-15 1:19 ` John Ogness
2019-02-15 13:47 ` Petr Mladek
2019-02-17 1:32 ` John Ogness
2019-02-21 13:51 ` Petr Mladek
2019-02-12 14:29 ` [RFC PATCH v1 05/25] printk-rb: add basic non-blocking reading interface John Ogness
2019-02-18 12:54 ` Petr Mladek
2019-02-19 21:44 ` John Ogness
2019-02-21 16:22 ` Petr Mladek
2019-02-12 14:29 ` [RFC PATCH v1 06/25] printk-rb: add blocking reader support John Ogness
2019-02-18 14:05 ` Petr Mladek
2019-02-19 21:47 ` John Ogness
2019-02-12 14:29 ` [RFC PATCH v1 07/25] printk-rb: add functionality required by printk John Ogness
2019-02-12 17:15 ` Linus Torvalds
2019-02-13 9:20 ` John Ogness
2019-02-18 15:59 ` Petr Mladek
2019-02-19 22:08 ` John Ogness
2019-02-22 9:58 ` Petr Mladek
2019-02-12 14:29 ` [RFC PATCH v1 08/25] printk: add ring buffer and kthread John Ogness
2019-02-12 15:47 ` Sergey Senozhatsky
2019-02-19 13:54 ` Petr Mladek
2019-03-04 7:38 ` Sergey Senozhatsky
2019-03-04 10:00 ` Sergey Senozhatsky
2019-03-04 11:07 ` Sergey Senozhatsky
2019-03-05 21:00 ` John Ogness
2019-03-06 15:57 ` Petr Mladek
2019-03-06 21:17 ` John Ogness
2019-03-06 22:22 ` John Ogness
2019-03-07 6:41 ` Sergey Senozhatsky
2019-03-07 6:51 ` Sergey Senozhatsky
2019-03-07 12:50 ` Petr Mladek
2019-03-07 5:15 ` Sergey Senozhatsky
2019-03-11 10:51 ` John Ogness
2019-03-12 9:58 ` Sergey Senozhatsky
2019-03-12 10:30 ` Petr Mladek
2019-03-07 12:06 ` John Ogness
2019-03-08 1:31 ` Sergey Senozhatsky
2019-03-08 10:04 ` Petr Mladek
2019-02-12 14:29 ` [RFC PATCH v1 09/25] printk: remove exclusive console hack John Ogness
2019-02-19 14:03 ` Petr Mladek
2019-02-12 14:29 ` [RFC PATCH v1 10/25] printk: redirect emit/store to new ringbuffer John Ogness
2019-02-20 9:01 ` Petr Mladek
2019-02-20 21:25 ` John Ogness
2019-02-22 14:43 ` Petr Mladek
2019-02-22 15:06 ` John Ogness
2019-02-22 15:25 ` Petr Mladek
2019-02-25 12:11 ` Petr Mladek
2019-02-25 16:41 ` John Ogness
2019-02-26 9:45 ` Petr Mladek
2019-02-12 14:29 ` [RFC PATCH v1 11/25] printk_safe: remove printk safe code John Ogness
2019-02-22 10:37 ` Petr Mladek
2019-02-22 10:37 ` Petr Mladek
2019-02-22 13:38 ` John Ogness
2019-02-22 15:15 ` Petr Mladek
2019-02-12 14:29 ` [RFC PATCH v1 12/25] printk: minimize console locking implementation John Ogness
2019-02-25 13:44 ` Petr Mladek
2019-02-12 14:29 ` [RFC PATCH v1 13/25] printk: track seq per console John Ogness
2019-02-25 14:59 ` Petr Mladek
2019-02-26 8:45 ` John Ogness
2019-02-26 13:11 ` Petr Mladek
2019-02-12 14:29 ` [RFC PATCH v1 14/25] printk: do boot_delay_msec inside printk_delay John Ogness
2019-02-12 14:29 ` [RFC PATCH v1 15/25] printk: print history for new consoles John Ogness
2019-02-26 14:58 ` Petr Mladek
2019-02-26 15:22 ` John Ogness
2019-02-27 9:02 ` Petr Mladek
2019-02-27 10:02 ` John Ogness
2019-02-27 13:12 ` Petr Mladek
2019-03-04 9:24 ` Sergey Senozhatsky
2019-02-12 14:29 ` [RFC PATCH v1 16/25] printk: implement CON_PRINTBUFFER John Ogness
2019-02-26 15:38 ` Petr Mladek
2019-02-12 14:29 ` [RFC PATCH v1 17/25] printk: add processor number to output John Ogness
2019-02-13 22:29 ` John Ogness
2019-02-12 14:29 ` [RFC PATCH v1 18/25] console: add write_atomic interface John Ogness
2019-02-12 14:29 ` [RFC PATCH v1 19/25] printk: introduce emergency messages John Ogness
2019-03-07 7:30 ` Sergey Senozhatsky
2019-03-08 10:31 ` Petr Mladek
2019-03-11 12:04 ` John Ogness
2019-03-12 2:51 ` Sergey Senozhatsky
2019-03-12 2:58 ` Sergey Senozhatsky
2019-02-12 14:29 ` [RFC PATCH v1 20/25] serial: 8250: implement write_atomic John Ogness
2019-02-27 9:46 ` Petr Mladek
2019-02-27 10:32 ` John Ogness
2019-02-27 13:55 ` Petr Mladek
2019-03-08 4:05 ` John Ogness
2019-03-08 4:17 ` John Ogness
2019-03-08 10:28 ` Petr Mladek
2019-02-12 14:29 ` [RFC PATCH v1 21/25] printk: implement KERN_CONT John Ogness
2019-02-12 14:30 ` [RFC PATCH v1 22/25] printk: implement /dev/kmsg John Ogness
2019-02-12 14:30 ` [RFC PATCH v1 23/25] printk: implement syslog John Ogness
2019-02-12 14:30 ` [RFC PATCH v1 24/25] printk: implement kmsg_dump John Ogness
2019-02-12 14:30 ` [RFC PATCH v1 25/25] printk: remove unused code John Ogness
2019-03-08 14:02 ` Sebastian Andrzej Siewior
2019-03-11 2:46 ` Sergey Senozhatsky
2019-03-11 8:18 ` Sebastian Andrzej Siewior
2019-03-12 9:38 ` Petr Mladek
2019-02-13 1:31 ` [RFC PATCH v1 00/25] printk: new implementation Sergey Senozhatsky
2019-02-13 13:43 ` John Ogness
2019-03-04 6:39 ` Sergey Senozhatsky
2019-02-13 1:41 ` Sergey Senozhatsky
2019-02-13 14:15 ` John Ogness
2019-03-04 5:31 ` Sergey Senozhatsky
2019-02-13 2:55 ` Sergey Senozhatsky
2019-02-13 14:43 ` John Ogness
2019-03-04 5:23 ` Sergey Senozhatsky
2019-03-07 9:53 ` John Ogness
2019-03-08 10:00 ` Petr Mladek
2019-03-11 10:54 ` Sergey Senozhatsky
2019-03-12 12:38 ` Petr Mladek
2019-03-12 15:15 ` John Ogness
2019-03-13 2:15 ` Sergey Senozhatsky
2019-03-13 8:19 ` John Ogness
2019-03-13 8:40 ` Sebastian Siewior
2019-03-13 9:27 ` Sergey Senozhatsky [this message]
2019-03-13 10:06 ` Sergey Senozhatsky
2019-03-14 9:27 ` Petr Mladek
2019-03-13 8:46 ` Sergey Senozhatsky
2019-03-14 9:14 ` Petr Mladek
2019-03-14 9:35 ` John Ogness
2019-03-13 2:00 ` Sergey Senozhatsky
2019-02-13 16:54 ` David Laight
2019-02-13 22:20 ` John Ogness
2019-02-13 22:20 ` John Ogness
2020-01-20 23:05 ` Eugeniu Rosca
2020-01-21 23:56 ` John Ogness
2020-01-22 2:34 ` Eugeniu Rosca
2020-01-22 7:31 ` Geert Uytterhoeven
2020-01-22 16:58 ` Eugeniu Rosca
2020-01-22 19:48 ` Geert Uytterhoeven
2020-01-24 16:09 ` Eugeniu Rosca
2020-01-27 12:32 ` Petr Mladek
2020-01-27 13:45 ` Eugeniu Rosca
2020-01-22 10:33 ` John Ogness
2020-01-24 12:13 ` Eugeniu Rosca
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=20190313092759.GA10060@jagdpanzerIV \
--to=sergey.senozhatsky.work@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=bigeasy@linutronix.de \
--cc=gnomes@lxorguk.ukuu.org.uk \
--cc=gregkh@linuxfoundation.org \
--cc=john.ogness@linutronix.de \
--cc=jslaby@suse.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-serial@vger.kernel.org \
--cc=peterz@infradead.org \
--cc=pfeiner@google.com \
--cc=pmladek@suse.com \
--cc=rostedt@goodmis.org \
--cc=sergey.senozhatsky@gmail.com \
--cc=torvalds@linux-foundation.org \
--cc=wonderfly@google.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.