Re: RFC: doubling IO_BUFSIZE

[Jim Meyering]

On Sun, May 25, 2014 at 4:51 AM, Pádraig Brady <address@hidden> wrote:
> On 05/24/2014 05:21 PM, Jim Meyering wrote:
>> On Sat, May 24, 2014 at 1:59 AM, Pádraig Brady <address@hidden> wrote:
>>> On 05/24/2014 06:32 AM, Jim Meyering wrote:
>>>> It looks like it makes sense to double IO_BUFSIZE once again.
>>>> What do you think?
>>>
>>> +1
>>>
>>> Significant enough to bump up I think,
>>> and we never saw regressions with this size.
>>>
>>> Please amend the date etc. at the top of the comment too.
>>> Here are the results from non x86 worth adding I think:
>>
>> Good point.  Done.
>>
>>> POWER7 3.55GHz, revision 2.1 IBM,8231-E2B
>>>    1024=1.3 GB/s
>>>    2048=2.5 GB/s
>>>    4096=4.8 GB/s
>>>    8192=9.2 GB/s
>>>   16384=16.8 GB/s
>>>   32768=28.0 GB/s
>>>   65536=41.4 GB/s
>>>  131072=54.8 GB/s
>>>  262144=40.0 GB/s
>>>  524288=34.5 GB/s
>>> 1048576=36.5 GB/s
>>
>> Nice numbers. It'd be interesting to see power consumption :-)
>> Can you determine RAM type and speed for that system?
>
> dmidecode is not available on this linux ppc system,
> though looking at specs for IBM Power 730 it says it takes
> 1066 MHz DDR3
>
> The numbers above are over the throughput of that though,
> so we're in cache land here anyway which each core on this system has:
> L3(4MB), L2(256KB), L1d(32KB), L1i(32KB)

Good point.  Adjusted and pushed.