Commit 4fe5934d authored by Gautham R. Shenoy's avatar Gautham R. Shenoy Committed by Rafael J. Wysocki
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ACPI: CPPC: Detect preferred core availability on online CPUs 



Commit 279f838a ("x86/amd: Detect preferred cores in
amd_get_boost_ratio_numerator()") introduced the ability to detect the
preferred core on AMD platforms by checking if there at least two
distinct highest_perf values.

However, it uses for_each_present_cpu() to iterate through all the
CPUs in the platform, which is problematic when the kernel is booted
with "nosmt=force" commandline option.

Hence limit the search to only the online CPUs.

Fixes: 279f838a ("x86/amd: Detect preferred cores in amd_get_boost_ratio_numerator()")
Reported-by: default avatarChristopher Harris <chris.harris79@gmail.com>
Closes: https://lore.kernel.org/lkml/CAM+eXpdDT7KjLV0AxEwOLkSJ2QtrsvGvjA2cCHvt1d0k2_C4Cw@mail.gmail.com/


Reviewed-by: default avatar"Mario Limonciello (AMD) (kernel.org)" <superm1@kernel.org>
Tested-by: default avatarChrisopher Harris <chris.harris79@gmail.com>
Signed-off-by: default avatarGautham R. Shenoy <gautham.shenoy@amd.com>
Link: https://patch.msgid.link/20251107074145.2340-2-gautham.shenoy@amd.com


Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 1642fabf

arch/x86/kernel/acpi/cppc.c

+1 −1
Original line number Diff line number Diff line
@@ -196,7 +196,7 @@ int amd_detect_prefcore(bool *detected) 
		break;

	}



	for_each_present_cpu(cpu) {

	for_each_online_cpu(cpu) {

		u32 tmp;

		int ret;