From: Tejun Heo <tj@kernel.org>
To: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>,
Linux PM list <linux-pm@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
horms@verge.net.au, "pavel@ucw.cz" <pavel@ucw.cz>,
Len Brown <lenb@kernel.org>
Subject: Re: [Update][PATCH] PM / Hibernate: Fix s2disk regression related to unlock_system_sleep()
Date: Wed, 18 Jan 2012 08:58:47 -0800 [thread overview]
Message-ID: <CAOS58YPW3hB3ibaYPLBqhu=2jZTAjjF7DZaXO=hK5tookAX7YA@mail.gmail.com> (raw)
In-Reply-To: <4F16F94C.4020000@linux.vnet.ibm.com>
Hello,
On Wed, Jan 18, 2012 at 8:54 AM, Srivatsa S. Bhat
<srivatsa.bhat@linux.vnet.ibm.com> wrote:
> + /*
> + * Don't use freezer_count() because we don't want the call to
> + * try_to_freeze() here.
> + *
> + * Reason:
> + * unlock_system_sleep() gets called in snapshot_read() and
> + * snapshot_write() when the freezing condition is still in effect.
> + * Which means, if we use try_to_freeze() here, it would make them
> + * enter the refrigerator, thus causing suspend-to-disk to lockup.
> + */
Yeap, much better but wouldn't it be better if the description was
higher level? ie. Explain why try_to_freeze() doesn't make sense for
this operation semantically and then, optionally, give an example of
breakage. It usually is lack of proper rationale / reasoning that
confuses people reading the code.
Thank you.
--
tejun
next prev parent reply other threads:[~2012-01-18 16:58 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-17 22:45 [PATCH] PM / Hibernate: Fix s2disk regression related to unlock_system_sleep() Rafael J. Wysocki
2012-01-17 23:15 ` [Update][PATCH] " Rafael J. Wysocki
2012-01-18 12:59 ` Srivatsa S. Bhat
2012-01-18 15:42 ` Tejun Heo
2012-01-18 16:54 ` Srivatsa S. Bhat
2012-01-18 16:58 ` Tejun Heo [this message]
2012-01-18 17:19 ` Srivatsa S. Bhat
2012-01-18 17:30 ` Tejun Heo
2012-01-18 17:33 ` Tejun Heo
2012-01-19 10:37 ` Pavel Machek
2012-01-19 10:55 ` Srivatsa S. Bhat
2012-01-19 17:40 ` Pavel Machek
2012-01-19 18:10 ` Srivatsa S. Bhat
2012-01-18 19:22 ` Srivatsa S. Bhat
2012-01-18 19:30 ` Tejun Heo
2012-01-18 19:46 ` Srivatsa S. Bhat
2012-01-18 20:29 ` Srivatsa S. Bhat
2012-01-18 22:04 ` Tejun Heo
2012-01-18 22:22 ` Rafael J. Wysocki
2012-01-19 14:40 ` Srivatsa S. Bhat
2012-01-19 22:35 ` Rafael J. Wysocki
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