From: Stefan Raspl <raspl@linux.vnet.ibm.com>
To: Li Zefan <lizf@cn.fujitsu.com>
Cc: linux-btrace@vger.kernel.org, Jens Axboe <jens.axboe@oracle.com>,
linux-kernel@vger.kernel.org, schwidefsky@de.ibm.com,
heiko.carstens@de.ibm.com
Subject: Re: [Patch] blktrace: remove debugfs entries on bad path
Date: Tue, 19 May 2009 06:46:57 +0000 [thread overview]
Message-ID: <4A1255E1.1060301@linux.vnet.ibm.com> (raw)
In-Reply-To: <4A1207DE.4000409@cn.fujitsu.com>
Li Zefan wrote:
> A better title:
> [Patch] blktrace: remove debugfs entries on bad path
>
> Stefan Raspl wrote:
>> debugfs directory entries for devices are not removed on bad path.
>
> Can you be more elaborate on how to reproduce this issue?
It can happen for most bad pathes within do_blk_trace_setup(). One
way to trigger is to set the Vmalloc space via the respective kernel
parameter to a value that is so small that it will not suffice for
the 2MB per device and cpu that is required. For instance, set
vmalloc\x10M and start blktrace on a system with 2 cpus on 7 devices.
Depending on how much Vmalloc space is still free, the final 2 or 3
devices will fail with a message like this:
BLKTRACESETUP(2) /dev/sdu failed: 5/Input/output error
Best regards,
Stefan Raspl
WARNING: multiple messages have this Message-ID (diff)
From: Stefan Raspl <raspl@linux.vnet.ibm.com>
To: Li Zefan <lizf@cn.fujitsu.com>
Cc: linux-btrace@vger.kernel.org, Jens Axboe <jens.axboe@oracle.com>,
linux-kernel@vger.kernel.org, schwidefsky@de.ibm.com,
heiko.carstens@de.ibm.com
Subject: Re: [Patch] blktrace: remove debugfs entries on bad path
Date: Tue, 19 May 2009 08:46:57 +0200 [thread overview]
Message-ID: <4A1255E1.1060301@linux.vnet.ibm.com> (raw)
In-Reply-To: <4A1207DE.4000409@cn.fujitsu.com>
Li Zefan wrote:
> A better title:
> [Patch] blktrace: remove debugfs entries on bad path
>
> Stefan Raspl wrote:
>> debugfs directory entries for devices are not removed on bad path.
>
> Can you be more elaborate on how to reproduce this issue?
It can happen for most bad pathes within do_blk_trace_setup(). One
way to trigger is to set the Vmalloc space via the respective kernel
parameter to a value that is so small that it will not suffice for
the 2MB per device and cpu that is required. For instance, set
vmalloc=10M and start blktrace on a system with 2 cpus on 7 devices.
Depending on how much Vmalloc space is still free, the final 2 or 3
devices will fail with a message like this:
BLKTRACESETUP(2) /dev/sdu failed: 5/Input/output error
Best regards,
Stefan Raspl
next prev parent reply other threads:[~2009-05-19 6:46 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-05-18 12:59 [Patch] Remove debugfs entries on bad path Stefan Raspl
2009-05-18 12:59 ` Stefan Raspl
2009-05-19 1:14 ` Li Zefan
2009-05-19 1:14 ` Li Zefan
2009-05-19 6:46 ` Stefan Raspl [this message]
2009-05-19 6:46 ` [Patch] blktrace: remove " Stefan Raspl
2009-05-19 7:07 ` Li Zefan
2009-05-19 7:07 ` Li Zefan
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