From: Tejun Heo <tj@kernel.org>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Petr Mladek <pmladek@suse.com>,
Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
Jan Kara <jack@suse.cz>,
Andrew Morton <akpm@linux-foundation.org>,
Peter Zijlstra <peterz@infradead.org>,
Rafael Wysocki <rjw@rjwysocki.net>, Pavel Machek <pavel@ucw.cz>,
Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>,
linux-kernel@vger.kernel.org,
Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Subject: Re: [RFC][PATCHv6 00/12] printk: introduce printing kernel thread
Date: Tue, 9 Jan 2018 14:17:05 -0800 [thread overview]
Message-ID: <20180109221705.GU3668920@devbig577.frc2.facebook.com> (raw)
In-Reply-To: <20180109170847.28b41eec@vmware.local.home>
Hello, Steven.
On Tue, Jan 09, 2018 at 05:08:47PM -0500, Steven Rostedt wrote:
> The scenario you listed would affect multiple CPUs and multiple CPUs
> would be flooding printk. In that case my patch WILL help. Because the
> current method, the first CPU to do the printk will get stuck doing the
> printk for ALL OTHER CPUs. With my patch, the printk load will migrate
> around and there will not be a single CPU that is stuck.
Maybe it can break out eventually but that can take a really long
time. It's OOM. Most of userland is waiting for reclaim. There
isn't all that much going on outside that and there can only be one
CPU which is OOMing. The kernel isn't gonna be all that chatty.
Thanks.
--
tejun
next prev parent reply other threads:[~2018-01-09 22:17 UTC|newest]
Thread overview: 79+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-04 13:48 [RFC][PATCHv6 00/12] printk: introduce printing kernel thread Sergey Senozhatsky
2017-12-04 13:48 ` [RFC][PATCHv6 01/12] printk: move printk_pending out of per-cpu Sergey Senozhatsky
2017-12-04 13:48 ` [RFC][PATCHv6 02/12] printk: introduce printing kernel thread Sergey Senozhatsky
2017-12-04 13:48 ` [RFC][PATCHv6 03/12] printk: consider watchdogs thresholds for offloading Sergey Senozhatsky
2017-12-04 13:48 ` [RFC][PATCHv6 04/12] printk: add sync printk_emergency API Sergey Senozhatsky
2017-12-04 13:48 ` [RFC][PATCHv6 05/12] printk: enable printk offloading Sergey Senozhatsky
2017-12-04 13:48 ` [RFC][PATCHv6 06/12] PM: switch between printk emergency modes Sergey Senozhatsky
2017-12-04 13:48 ` [RFC][PATCHv6 07/12] printk: register syscore notifier Sergey Senozhatsky
2017-12-04 13:48 ` [RFC][PATCHv6 08/12] printk: force printk_kthread to offload printing Sergey Senozhatsky
2017-12-04 13:48 ` [RFC][PATCHv6 09/12] printk: do not cond_resched() when we can offload Sergey Senozhatsky
2017-12-04 13:48 ` [RFC][PATCHv6 10/12] printk: move offloading logic to per-cpu Sergey Senozhatsky
2017-12-04 13:48 ` [RFC][PATCHv6 11/12] printk: add offloading watchdog API Sergey Senozhatsky
2017-12-04 13:48 ` [RFC][PATCHv6 12/12] printk: improve printk offloading mechanism Sergey Senozhatsky
2017-12-04 13:53 ` [PATCH 0/4] printk: offloading testing module/trace events Sergey Senozhatsky
2017-12-04 13:53 ` [PATCH 1/4] printk/lib: add offloading trace events and test_printk module Sergey Senozhatsky
2017-12-04 13:53 ` [PATCH 2/4] printk/lib: simulate slow consoles Sergey Senozhatsky
2017-12-04 13:53 ` [PATCH 3/4] printk: add offloading takeover traces Sergey Senozhatsky
2017-12-04 13:53 ` [PATCH 4/4] printk: add task name and CPU to console messages Sergey Senozhatsky
2017-12-14 14:27 ` [RFC][PATCHv6 00/12] printk: introduce printing kernel thread Petr Mladek
2017-12-14 14:39 ` Sergey Senozhatsky
2017-12-15 15:55 ` Steven Rostedt
2017-12-14 15:25 ` Tejun Heo
2017-12-14 17:55 ` Steven Rostedt
2017-12-14 18:11 ` Tejun Heo
2017-12-14 18:21 ` Steven Rostedt
2017-12-22 0:09 ` Tejun Heo
2017-12-22 4:19 ` Steven Rostedt
2017-12-28 6:48 ` Sergey Senozhatsky
2017-12-28 10:07 ` Sergey Senozhatsky
2017-12-29 13:59 ` Tetsuo Handa
2017-12-31 1:44 ` Sergey Senozhatsky
2018-01-09 20:06 ` Tejun Heo
2018-01-09 22:08 ` Tetsuo Handa
2018-01-09 22:17 ` Tejun Heo
2018-01-11 11:14 ` Tetsuo Handa
2018-01-09 22:08 ` Steven Rostedt
2018-01-09 22:17 ` Tejun Heo [this message]
2018-01-09 22:47 ` Steven Rostedt
2018-01-09 22:53 ` Tejun Heo
2018-01-10 7:18 ` Steven Rostedt
2018-01-10 14:04 ` Tejun Heo
2017-12-15 2:10 ` Sergey Senozhatsky
2017-12-15 3:18 ` Steven Rostedt
2017-12-15 5:06 ` Sergey Senozhatsky
2017-12-15 6:52 ` Sergey Senozhatsky
2017-12-15 15:39 ` Steven Rostedt
2017-12-15 8:31 ` Petr Mladek
2017-12-15 8:42 ` Sergey Senozhatsky
2017-12-15 9:08 ` Petr Mladek
2017-12-15 15:47 ` Steven Rostedt
2017-12-18 9:36 ` Sergey Senozhatsky
2017-12-18 10:36 ` Sergey Senozhatsky
2017-12-18 12:35 ` Sergey Senozhatsky
2017-12-18 13:51 ` Petr Mladek
2017-12-18 13:31 ` Petr Mladek
2017-12-18 13:39 ` Sergey Senozhatsky
2017-12-18 14:13 ` Petr Mladek
2017-12-18 17:46 ` Steven Rostedt
2017-12-19 1:03 ` Sergey Senozhatsky
2017-12-19 1:08 ` Steven Rostedt
2017-12-19 1:24 ` Sergey Senozhatsky
2017-12-19 2:03 ` Steven Rostedt
2017-12-19 2:46 ` Sergey Senozhatsky
2017-12-19 3:38 ` Steven Rostedt
2017-12-19 4:58 ` Sergey Senozhatsky
2017-12-19 14:40 ` Steven Rostedt
2017-12-20 7:46 ` Sergey Senozhatsky
2017-12-19 14:31 ` Michal Hocko
2017-12-20 7:10 ` Sergey Senozhatsky
2017-12-20 12:06 ` Tetsuo Handa
2017-12-21 6:52 ` Sergey Senozhatsky
2017-12-19 4:36 ` Sergey Senozhatsky
2017-12-18 14:10 ` Petr Mladek
2017-12-19 1:09 ` Sergey Senozhatsky
2017-12-15 15:42 ` Steven Rostedt
2017-12-15 15:19 ` Steven Rostedt
2017-12-19 0:52 ` Sergey Senozhatsky
2017-12-19 1:03 ` Steven Rostedt
2018-01-05 2:54 ` Sergey Senozhatsky
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=20180109221705.GU3668920@devbig577.frc2.facebook.com \
--to=tj@kernel.org \
--cc=akpm@linux-foundation.org \
--cc=jack@suse.cz \
--cc=linux-kernel@vger.kernel.org \
--cc=pavel@ucw.cz \
--cc=penguin-kernel@I-love.SAKURA.ne.jp \
--cc=peterz@infradead.org \
--cc=pmladek@suse.com \
--cc=rjw@rjwysocki.net \
--cc=rostedt@goodmis.org \
--cc=sergey.senozhatsky.work@gmail.com \
--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.