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From: ersatz splatt <ersatzsplatt@gmail.com>
To: Jack Wang <jack_wang@usish.com>
Cc: lindar_liu@usish.com, linux-scsi@vger.kernel.org
Subject: Re: pm8001 performance degradation?
Date: Mon, 11 Jul 2011 19:46:25 -0700	[thread overview]
Message-ID: <CAHQAjVFm95Czhz=P7r_OX1NUuw_nipubn=imaKAsT+a0R5sVuw@mail.gmail.com> (raw)
In-Reply-To: <CAHQAjVG_cvvEX99A4ma5waSMs6hjWB_Bgy0oDZ4LgyzwwOpcjQ@mail.gmail.com>

Please let me know if you would like any more details.

Can you point to the degradation reference in earlier mail?



On Mon, Jul 11, 2011 at 7:44 PM, ersatz splatt <ersatzsplatt@gmail.com> wrote:
> I have one HBA connected directly to 4 SAS drives ... using a single 1
> to four cable.
>
>
> On Mon, Jul 11, 2011 at 6:27 PM, Jack Wang <jack_wang@usish.com> wrote:
>>> Hello Jack Wang and Lindar Liu,
>>>
>>>
>>> I am running the pm8001 driver (on applicable hardware including a
>>> several core SMP server).
>>>
>>> When I run on an older kernel -- e.g. 2.6.34.7 -- I get about 73Kiops
>>> via an fio test.
>>>
>>> When I run a current kernel -- e.g. 2.6.39.2 -- on the same system and
>>> same storage I get about 15Kiops running the same fio test.
>>>
>>> Perhaps something has changes in the kernel that is not being accounted
>> for?
>>> Are you two still maintaining this driver?
>>>
>>>
>>> Regards,
>>> David
>> [Jack Wang]  Could you give your detailed topology, I will later try to
>> investigate the performance issue, but as I remember an Intel developer
>> reports in mailist some changes in block layer lead to JBOD performance
>> degradation.
>>
>>
>
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  reply	other threads:[~2011-07-12  2:46 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-07-11 19:06 pm8001 performance degradation? ersatz splatt
2011-07-12  1:27 ` Jack Wang
2011-07-12  2:44   ` ersatz splatt
2011-07-12  2:46     ` ersatz splatt [this message]
2011-07-12  4:18     ` Jack Wang
2011-07-12 19:34       ` ersatz splatt
2011-07-13  3:15         ` ersatz splatt
2011-07-13  4:08           ` Jack Wang

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