From 4fe5934db4a7187d358f1af1b3ef9b6dd59bce58 Mon Sep 17 00:00:00 2001 From: "Gautham R. Shenoy" Date: Fri, 7 Nov 2025 13:11:41 +0530 Subject: [PATCH] ACPI: CPPC: Detect preferred core availability on online CPUs Commit 279f838a61f9 ("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: 279f838a61f9 ("x86/amd: Detect preferred cores in amd_get_boost_ratio_numerator()") Reported-by: Christopher Harris Closes: https://lore.kernel.org/lkml/CAM+eXpdDT7KjLV0AxEwOLkSJ2QtrsvGvjA2cCHvt1d0k2_C4Cw@mail.gmail.com/ Reviewed-by: "Mario Limonciello (AMD) (kernel.org)" Tested-by: Chrisopher Harris Signed-off-by: Gautham R. Shenoy Link: https://patch.msgid.link/20251107074145.2340-2-gautham.shenoy@amd.com Signed-off-by: Rafael J. Wysocki --- arch/x86/kernel/acpi/cppc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kernel/acpi/cppc.c b/arch/x86/kernel/acpi/cppc.c index 7047124490f6..d7c8ef1e354d 100644 --- a/arch/x86/kernel/acpi/cppc.c +++ b/arch/x86/kernel/acpi/cppc.c @@ -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; -- 2.47.3