Re: kern/56550: swapctl: SWAP_STATS different to SWAP_NSWAP (1 != 3)

[Michael Cheponis <michael.cheponis%gmail.com@localhost>]

The following reply was made to PR bin/56550; it has been noted by GNATS.

From: Michael Cheponis <michael.cheponis%gmail.com@localhost>
To: gnats-bugs%netbsd.org@localhost
Cc: gnats-admin%netbsd.org@localhost, netbsd-bugs%netbsd.org@localhost, mac%culver.net@localhost
Subject: Re: kern/56550: swapctl: SWAP_STATS different to SWAP_NSWAP (1 != 3)
Date: Sun, 26 Dec 2021 14:32:57 -0800

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 I'm not sure I can do that because the error only happens intermittently.
 If I start the system with 1 swapfile, then add e.g. 3 more, then
 *sometimes* I get that  1 != 4 message from "sysctl -l"   And, oddly, I can
 keep trying "sysctl -l" and it works, and then, suddenly, I will get one
 that says  1 != 4 again.
 
 I do not know how to reliably 'trigger' this.   And, it is 'transitory' in
 that I would guess I get maybe one 1 != 4 every 50 successful "sysctl -l"
 operations.
 
 I will try to get this to happen more frequently so I can catch it with
 ktrace.  (which options do you suggest?  I'm thinking "ktrace -d -p
 <shell-pid>" )
 
 Thanks for looking at this,
 -Mike
 
 
 On Sun, Dec 26, 2021 at 1:55 PM Taylor R Campbell <riastradh%netbsd.org@localhost>
 wrote:
 
 > The following reply was made to PR bin/56550; it has been noted by GNATS.
 >
 > From: Taylor R Campbell <riastradh%NetBSD.org@localhost>
 > To: mac%culver.net@localhost
 > Cc: gnats-bugs%NetBSD.org@localhost
 > Subject: Re: kern/56550: swapctl: SWAP_STATS different to SWAP_NSWAP (1 !=
 > 3)
 > Date: Sun, 26 Dec 2021 21:53:51 +0000
 >
 >  Can you share ktrace output, from a working swapctl run and a
 >  nonworking swapctl run?
 >
 >
 
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 <div dir=3D"ltr"><div class=3D"gmail_default" style=3D"font-family:arial,he=
 lvetica,sans-serif;font-size:small">I&#39;m not sure I can do that because =
 the error only happens intermittently.=C2=A0 If I start the system with 1 s=
 wapfile, then add e.g. 3 more, then *sometimes* I get that=C2=A0 1 !=3D 4 m=
 essage from &quot;sysctl -l&quot;=C2=A0 =C2=A0And, oddly, I can keep trying=
  &quot;sysctl -l&quot; and it works, and then, suddenly, I will get one tha=
 t says=C2=A0 1 !=3D 4 again.</div><div class=3D"gmail_default" style=3D"fon=
 t-family:arial,helvetica,sans-serif;font-size:small"><br></div><div class=
 =3D"gmail_default" style=3D"font-family:arial,helvetica,sans-serif;font-siz=
 e:small">I do not know how to reliably &#39;trigger&#39; this.=C2=A0 =C2=A0=
 And, it is &#39;transitory&#39; in that I would guess I get maybe one 1 !=
 =3D 4 every 50 successful &quot;sysctl -l&quot; operations.</div><div class=
 =3D"gmail_default" style=3D"font-family:arial,helvetica,sans-serif;font-siz=
 e:small"><br></div><div class=3D"gmail_default" style=3D"font-family:arial,=
 helvetica,sans-serif;font-size:small">I will try to get this to happen more=
  frequently so I can catch it with ktrace.=C2=A0 (which options do you sugg=
 est?=C2=A0 I&#39;m thinking &quot;ktrace -d -p &lt;shell-pid&gt;&quot; )</d=
 iv><div class=3D"gmail_default" style=3D"font-family:arial,helvetica,sans-s=
 erif;font-size:small"><br></div><div class=3D"gmail_default" style=3D"font-=
 family:arial,helvetica,sans-serif;font-size:small">Thanks for looking at th=
 is,</div><div class=3D"gmail_default" style=3D"font-family:arial,helvetica,=
 sans-serif;font-size:small">-Mike</div><div class=3D"gmail_default" style=
 =3D"font-family:arial,helvetica,sans-serif;font-size:small"><br></div></div=
 ><br><div class=3D"gmail_quote"><div dir=3D"ltr" class=3D"gmail_attr">On Su=
 n, Dec 26, 2021 at 1:55 PM Taylor R Campbell &lt;<a href=3D"mailto:riastrad=
 h%netbsd.org@localhost">riastradh%netbsd.org@localhost</a>&gt; wrote:<br></div><blockquote clas=
 s=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;border-left:1px solid r=
 gb(204,204,204);padding-left:1ex">The following reply was made to PR bin/56=
 550; it has been noted by GNATS.<br>
 <br>
 From: Taylor R Campbell &lt;riastradh%NetBSD.org@localhost&gt;<br>
 To: <a href=3D"mailto:mac%culver.net@localhost"; target=3D"_blank">mac%culver.net@localhost</a><=
 br>
 Cc: gnats-bugs%NetBSD.org@localhost<br>
 Subject: Re: kern/56550: swapctl: SWAP_STATS different to SWAP_NSWAP (1 !=
 =3D 3)<br>
 Date: Sun, 26 Dec 2021 21:53:51 +0000<br>
 <br>
 =C2=A0Can you share ktrace output, from a working swapctl run and a<br>
 =C2=A0nonworking swapctl run?<br>
 <br>
 </blockquote></div>
 
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