[ale] Ouch

[Alex Carver]

This also appears to extend to ARM64 as well:
https://lwn.net/Articles/740393/

That sucks more given how many ARM-based processors are around
(including phones) and can't exactly handle a 20-30% performance hit.



On 2018-01-03 07:04, Jim Kinney via Ale wrote:
> Good data. Thanks. 
> 
> On Wed, 2018-01-03 at 07:47 -0500, Solomon Peachy via Ale wrote:
>> On Tue, Jan 02, 2018 at 10:24:07PM -0500, Raj Wurttemberg via Ale
>> wrote:
>>> Ohh.. yeah... Ouch!!  A 30% performance hit?!?!  
>>
>> It's actually not _that_ bad -- it's a significant performance hit
>> on 
>> making system calls -- the only measurements I've seen have shown a
>> 38% 
>> increase in the overhead to read() --actual processing is unaffected.
>>
>> On the other hand, I/O intensive workloads are the most heavily 
>> impacted.  The PostgreSQL folks have done some preliminary
>> benchmarks 
>> and it's not pretty:
>>
>>   https://www.postgresql.org/message-id/20180102222354.qikjmf7dvnjgbk
>> xe at alap3.anarazel.de
>>
>>  - Solomon