From: Michal Hocko <mhocko@kernel.org>
To: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: Petr Mladek <pmladek@suse.com>,
Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
Steven Rostedt <rostedt@goodmis.org>,
John Ogness <john.ogness@linutronix.de>,
Andrew Morton <akpm@linux-foundation.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
linux-kernel@vger.kernel.org
Subject: Re: [RFC PATCH] printk: Introduce "store now but print later" prefix.
Date: Tue, 5 Mar 2019 13:57:22 +0100 [thread overview]
Message-ID: <20190305125722.GG28468@dhcp22.suse.cz> (raw)
In-Reply-To: <201903050123.x251N312025685@www262.sakura.ne.jp>
On Tue 05-03-19 10:23:03, Tetsuo Handa wrote:
[...]
> Also, both nopage_rs in warn_alloc() and oom_rs in oom_kill_process() are not
> working well. This is because ___ratelimit() function assumes that operations
> to be ratelimited complete fast enough to be able to repeat many times within
> a second. If one operation to be ratelimited takes many seconds (or even
> minutes), ___ratelimit() becomes always true and can not ratelimit at all.
And this is a fundamental problem of the ratelimiting and something to
think about and address. The underlying assumption of the ratelimit
implementation that the throttled operation is mostly too short to
consider is just wrong in this and potentially many other cases. Well
basically whenever the API is used for printing. So rather than working
around this and complicating the code around I would focus on making
ratelimit implementation more robust for long taking operations.
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2019-03-05 12:57 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-23 4:42 [RFC PATCH] printk: Introduce "store now but print later" prefix Tetsuo Handa
2019-03-04 3:22 ` Sergey Senozhatsky
2019-03-04 11:40 ` Tetsuo Handa
2019-03-04 12:09 ` Sergey Senozhatsky
2019-03-04 14:23 ` Petr Mladek
2019-03-04 14:37 ` Sergey Senozhatsky
2019-03-05 1:23 ` Tetsuo Handa
2019-03-05 7:52 ` Sergey Senozhatsky
2019-03-05 12:57 ` Michal Hocko [this message]
2019-03-06 10:04 ` Petr Mladek
2019-03-06 14:27 ` Sergey Senozhatsky
2019-03-06 18:24 ` Tetsuo Handa
2019-03-15 10:49 ` Tetsuo Handa
2019-03-20 15:04 ` Petr Mladek
2019-03-20 15:25 ` ratelimit API: was: " Petr Mladek
2019-03-21 8:13 ` Tetsuo Handa
2019-03-21 8:49 ` Michal Hocko
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=20190305125722.GG28468@dhcp22.suse.cz \
--to=mhocko@kernel.org \
--cc=akpm@linux-foundation.org \
--cc=john.ogness@linutronix.de \
--cc=linux-kernel@vger.kernel.org \
--cc=penguin-kernel@i-love.sakura.ne.jp \
--cc=pmladek@suse.com \
--cc=rostedt@goodmis.org \
--cc=sergey.senozhatsky.work@gmail.com \
--cc=sergey.senozhatsky@gmail.com \
--cc=torvalds@linux-foundation.org \
/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.