From: Peter Zijlstra <peterz@infradead.org>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "Ted Ts'o" <tytso@mit.edu>, Alan Cox <alan@lxorguk.ukuu.org.uk>,
Greg KH <greg@kroah.com>,
linux-kernel <linux-kernel@vger.kernel.org>,
Ingo Molnar <mingo@elte.hu>
Subject: Re: printk() vs tty_io
Date: Fri, 16 Dec 2011 14:25:55 +0100 [thread overview]
Message-ID: <1324041955.18942.97.camel@twins> (raw)
In-Reply-To: <CA+55aFwhFoU5Fp_VTMtVU7XFMZiNvy1J7n7YJsVBu+-k-EH0Nw@mail.gmail.com>
On Thu, 2011-12-15 at 09:08 -0800, Linus Torvalds wrote:
> Peter, why do you want to try to work from under the rq lock?
As Ingo already mentioned, there was no strong reason. The rationale was
reducing surprise lockups like that xtime_lock thing. Also, there are
various WARNs in the scheduler code that could possibly trigger and
cause a deadlock.
Then again, they're not supposed to trigger and mostly if they do we
don't get an insta deadlock (at least not on the consoles I've used),
but there is the possibility of course.
I'm not sure the WARNs are enough reason to invent a new async printk
facility, but if you feel strongly about that I can look into doing it.
next prev parent reply other threads:[~2011-12-16 13:27 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-12-13 19:33 printk() vs tty_io Peter Zijlstra
2011-12-13 23:52 ` Linus Torvalds
2011-12-14 9:38 ` Peter Zijlstra
2011-12-14 10:43 ` Alan Cox
2011-12-14 10:56 ` Peter Zijlstra
2011-12-14 14:05 ` Ted Ts'o
2011-12-14 14:23 ` Peter Zijlstra
2011-12-14 15:54 ` Linus Torvalds
2011-12-15 9:56 ` Peter Zijlstra
2011-12-15 10:32 ` Alan Cox
2011-12-15 10:55 ` Peter Zijlstra
2011-12-15 17:08 ` Linus Torvalds
2011-12-15 18:07 ` Ingo Molnar
2011-12-15 21:22 ` Alan Cox
2011-12-16 13:25 ` Peter Zijlstra [this message]
2011-12-15 19:02 ` Greg KH
2011-12-14 6:59 ` Ingo Molnar
2011-12-14 9:40 ` [PATCH] arch, early_printk: Consolidate early_printk() implementations Peter Zijlstra
2011-12-14 9:41 ` [PATCH] lockdep: Enable earlyprintk output Peter Zijlstra
2011-12-14 9:43 ` printk() vs tty_io Peter Zijlstra
2011-12-14 9:46 ` Ingo Molnar
2011-12-21 12:03 ` Stijn Devriendt
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