| Date | Mon, 13 Nov 2023 10:03:17 +1000 | Subject | Re: [PATCH RFC 02/22] x86: intel_epb: Don't rely on link order | From | Gavin Shan <> |
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On 11/7/23 20:29, Russell King (Oracle) wrote: > From: James Morse <james.morse@arm.com> > > intel_epb_init() is called as a subsys_initcall() to register cpuhp > callbacks. The callbacks make use of get_cpu_device() which will return > NULL unless register_cpu() has been called. register_cpu() is called > from topology_init(), which is also a subsys_initcall(). > > This is fragile. Moving the register_cpu() to a different > subsys_initcall() leads to a NULL dereference during boot. > > Make intel_epb_init() a late_initcall(), user-space can't provide a > policy before this point anyway. > > Signed-off-by: James Morse <james.morse@arm.com> > Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> > --- > subsys_initcall_sync() would be an option, but moving the register_cpu() > calls into ACPI also means adding a safety net for CPUs that are online > but not described properly by firmware. This lives in subsys_initcall_sync(). > --- > arch/x86/kernel/cpu/intel_epb.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) >
Reviewed-by: Gavin Shan <gshan@redhat.com>
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