From: Asias He <asias@redhat.com>
To: Jens Axboe <axboe@kernel.dk>
Cc: fio@vger.kernel.org
Subject: Re: Why fio triggers reading of device serial number
Date: Fri, 18 May 2012 22:10:03 +0800 [thread overview]
Message-ID: <4FB6583B.4050708@redhat.com> (raw)
In-Reply-To: <4FB61DD8.7020800@kernel.dk>
On 05/18/2012 06:00 PM, Jens Axboe wrote:
> On 05/18/2012 08:28 AM, Asias He wrote:
>> Hi, List
>>
>> I noticed that fio triggers reading of device serial number when fio
>> starts (one read) and stops (lots of read). I was wondering if fio was
>> reading the sysfs attribute directly in fio's code,
>> e.g./sys/block/vda/serial, or it triggered something which make udevd to
>> read it.
>>
>> trace-cmd shows it seems udevd is reading:
>>
>> udevd-6856 [006] xxx: function: dev_attr_show
>> udevd-6856 [006] xxx: function: virtblk_serial_show
>>
>> Any ideas? Thanks.
>
> Probably mtime changing of the special file inode, causing some udev
> rule to attempt to re-read the id/serial. Fio doesn't read the serial
> number.
OK. Thanks, Jens.
--
Asias
prev parent reply other threads:[~2012-05-18 14:10 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <4FB5EA0D.7030402@redhat.com>
2012-05-18 6:28 ` Why fio triggers reading of device serial number Asias He
2012-05-18 10:00 ` Jens Axboe
2012-05-18 14:10 ` Asias He [this message]
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