LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
* recent patch "x86/acpi: Prevent X2APIC id 0xffffffff from being accounted"
@ 2018-04-27  7:21 Jan Beulich
  2018-04-27  8:32 ` Dou Liyang
  0 siblings, 1 reply; 6+ messages in thread
From: Jan Beulich @ 2018-04-27  7:21 UTC (permalink / raw)
  To: douly.fnst, tglx; +Cc: linux-kernel

Hello,

I've just stumbled across this commit, and I'm wondering if that's actually
correct (I too have at least one system where such IDs are reported in
MADT): For offline/absent CPUs, the firmware may not know the APIC IDs
at the point MADT is built, so I think it is quite reasonable to put ~0 in
there. The ACPID spec specifically calls out that the IDs must not change
across sleep states, which implies to me that they may change across an
offline period of a CPU. IOW I think such entries still need to contribute to
the count of disabled CPUs.

I notice a similar change has been done for the xAPIC case a while ago
by you, Thomas.

Jan

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2018-05-02  8:11 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-04-27  7:21 recent patch "x86/acpi: Prevent X2APIC id 0xffffffff from being accounted" Jan Beulich
2018-04-27  8:32 ` Dou Liyang
2018-04-27 12:09   ` Jan Beulich
2018-05-02  1:56     ` Dou Liyang
2018-05-02  6:39       ` Jan Beulich
2018-05-02  8:10         ` Dou Liyang

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).