From: Dave Jones <davej@redhat.com>
To: Wu Fengguang <fengguang.wu@intel.com>
Cc: Thomas Renninger <trenn@suse.de>, LKML <linux-kernel@vger.kernel.org>
Subject: Re: [BUGFIX] cpufreq: dont BUG_ON uninitialized policy cpu
Date: Wed, 13 Jan 2010 01:32:46 -0500 [thread overview]
Message-ID: <20100113063246.GA20803@redhat.com> (raw)
In-Reply-To: <20100113051438.GA32519@localhost>
On Wed, Jan 13, 2010 at 01:14:38PM +0800, Wu Fengguang wrote:
> Remove a BUG_ON which is always triggered here after commit 0b19a310eebb93:
>
> --- linux-mm.orig/drivers/cpufreq/cpufreq.c 2010-01-13 13:06:03.000000000 +0800
> +++ linux-mm/drivers/cpufreq/cpufreq.c 2010-01-13 13:06:57.000000000 +0800
> @@ -72,7 +72,8 @@ int lock_policy_rwsem_##mode \
> (int cpu) \
> { \
> int policy_cpu = per_cpu(cpufreq_policy_cpu, cpu); \
> - BUG_ON(policy_cpu == -1); \
> + if (policy_cpu == -1) \
> + return -1; \
> down_##mode(&per_cpu(cpu_policy_rwsem, policy_cpu)); \
> if (unlikely(!cpu_online(cpu))) { \
> up_##mode(&per_cpu(cpu_policy_rwsem, policy_cpu)); \
So instead of always BUG'ing, we'll always fail to get the lock ?
How can this be correct ?
This makes no sense. cpufreq_update_policy shouldn't be called without
an existing policy. Can someone send me the full trace ?
Andrew cc'd me on a revert of Thomas's last patch to this file,
but again, no trace, and I can't find the mails he refers to.
Dave
next prev parent reply other threads:[~2010-01-13 6:32 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-01-13 5:14 [BUGFIX] cpufreq: dont BUG_ON uninitialized policy cpu Wu Fengguang
2010-01-13 6:32 ` Dave Jones [this message]
2010-01-13 12:42 ` Thomas Renninger
2010-01-13 12:48 ` Wu Fengguang
2010-01-13 15:59 ` Dave Jones
2010-01-14 2:42 ` Wu Fengguang
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=20100113063246.GA20803@redhat.com \
--to=davej@redhat.com \
--cc=fengguang.wu@intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=trenn@suse.de \
/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.