kern/181632: 9.2-RC3 - on resume from suspend, disk operations are slower

[Mike Harding]

The following reply was made to PR kern/181632; it has been noted by GNATS.

From: Mike Harding <mvharding at gmail.com>
To: bug-followup at FreeBSD.org
Cc:  
Subject: Re: kern/181632: 9.2-RC3 - on resume from suspend, disk operations
 are slower
Date: Sat, 31 Aug 2013 10:12:00 -0700

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 I reverted the single line at
 
 http://svnweb.freebsd.org/base/stable/9/sys/dev/acpica/acpi_cpu.c?annotate=244616&pathrev=244616#l978
 
 to the previous version which was just
 
 ACPI_ENABLE_IRQS();
 
 instead of
 
 acpi_cpu_c1();
 
 and the problem does not occur.  The second line does 'sti; hlt' and the
 former just does 'sti'.
 
 Given that the code says
 
 /* If disabled, take the safe path. */  977 if (is_idle_disabled(sc)) {  978
 acpi_cpu_c1();  979 return;  980 }
 and then does a 'hlt' or idle if idle is disabled, this might be a problem.
 
 --001a11c388b2efa98404e5416fa7
 Content-Type: text/html; charset=ISO-8859-1
 Content-Transfer-Encoding: quoted-printable
 
 <div dir=3D"ltr"><div class=3D""><img class=3D"" id=3D":2re" src=3D"https:/=
 /mail.google.com/mail/u/0/images/cleardot.gif" alt=3D""></div><div><div>I r=
 everted the single line at<br><br><a href=3D"http://svnweb.freebsd.org/base=
 /stable/9/sys/dev/acpica/acpi_cpu.c?annotate=3D244616&pathrev=3D244616#=
 l978" target=3D"_blank">http://svnweb.freebsd.org/base/stable/9/sys/dev/acp=
 ica/acpi_cpu.c?annotate=3D244616&pathrev=3D244616#l978</a><br>
 
 <br></div>to the previous version which was just<br><br>ACPI_ENABLE_IRQS();=
 <br><br></div><div>instead of<br><br>acpi_cpu_c1();<br><br></div><div>and t=
 he problem does not occur.=A0 The second line does 'sti; hlt' and t=
 he former just does 'sti'.<br>
 
 <br></div><div>Given that the code says<br></div><div><br></div><div class=
 =3D"gmail_extra"><table cellpadding=3D"0" cellspacing=3D"0"><tbody><tr><td>=
     /* If disabled, take the safe path. */</td>
 </tr>
 
 
 
 
 <tr>
 <td>977</td>
 
 <td>    if (is_idle_disabled(sc)) {</td>
 </tr>
 
 
 
 
 <tr>
 <td>978</td>
 
 <td>        acpi_cpu_c1();</td>
 </tr>
 
 
 
 
 <tr>
 <td>979</td>
 
 <td>        return;</td>
 </tr>
 
 
 
 
 <tr>
 <td>980</td>
 
 <td>    }</td></tr></tbody></table><br></div>and then does a 'hlt' =
 or idle if idle is disabled, this might be a problem.</div>
 
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