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From: Arthur Chance <freebsd@qeng-ho.org>
Subject: Re: Swap on SSD
To: Frank Leonhardt <frank2@fjl.co.uk>, Robert Huff <roberthuff@rcn.com>
Cc: freebsd-questions@freebsd.org
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Date: Wed, 7 Feb 2018 18:31:13 +0000
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On 07/02/2018 15:01, Frank Leonhardt wrote:
> On 2018-02-05 18:53, Robert Huff wrote:
>> Frank Leonhardt writes:
>>
>>>  FreeBSD doesn't actually swap these days; uses demand paging.
>>
>>     Possible evidence to the contrary:
>>     On a system running:
>>
>> FreeBSD 12.0-CURRENT #0 r326723: Sat Dec  9 12:30:04 EST 2017 amd64
>>
>>     top shows:
>>
>> last pid: 57956;  load averages:  2.02,  2.01,  1.95   up 57+19:09:04 
>> 13:49:29
>> 132 processes: 3 running, 129 sleeping
>> CPU: 38.7% user,  0.4% nice,  7.9% system,  0.0% interrupt, 53.0% idle
>> Mem: 2264M Active, 2303M Inact, 1478M Laundry, 1525M Wired, 761M Buf,
>> 115M Free
>> Swap: 17G Total, 996M Used, 16G Free, 5% Inuse
>>
>>     So ... is "Swap" an incorrect label, or is actual swapping
>> going on?
> 
> Yes, it's an incorrect label.

Pretty much like referring to SSD storage as "disk" when it's all
rectangular slabs. The historical name lingers on long after the
technology becomes obsolete.

-- 
An amusing coincidence: log2(58) = 5.858 (to 0.0003% accuracy).