pcc_data_alloc(9)

💅 pcc_data_alloc — the kernel API manual, bestie edition 🎀

okay so real talk, this is the man page for pcc_data_alloc(9) from the Kernel API Manual, and it's lowkey iconic for such a tiny function. sit down, grab a strawberry, we're getting into it 🍓

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✨ NAME ✨

pcc_data_alloc — literally just allocates the pcc_data memory for the pcc subspace. that's it. that's the whole vibe. no cap. 💖

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🦋 SYNOPSIS 🦋

int pcc_data_alloc (int pcc_ss_id );

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🌸 ARGUMENTS 🌸

• pcc_ss_id — the PCC Subspace index, exactly as it shows up in the PCC client ACPI package. that's the number it wants, bestie 🫶

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👑 DESCRIPTION 👑

so what this function actually does is check and allocate the cppc_pcc_data memory. 💅

here's the tea tho — on some processor configurations it's fully possible that the same subspace is shared between multiple CPUs. and this is seen especially in CPUs with hardware multi-threading support. the way that happens 😭 like yes, multiple CPUs, one subspace, they're sharing, they're collaborating, main character energy for the whole package ngl 🔥

so yeah, it checks first, then allocates. it's giving responsible. it's giving "did you check before you committed." we love to see it ✨

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⭐ RETURN ⭐

0 for success, errno for failure. periodt. 💀

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🌈 SEE ALSO 🌈

Kernel file ./drivers/acpi/cppc_acpi.c — and honestly the whole friend group showed up for this one, look at this squad:

• acpi_get_psd_map(9)
• cpc_ffh_supported(9)
• cpc_supported_by_cpu(9)
• acpi_cppc_processor_probe(9)
• acpi_cppc_processor_exit(9)
• cpc_read_ffh(9)
• cpc_read_ffh_fb_ctrs(9)
• cpc_write_ffh(9)
• cppc_get_desired_perf(9)
• cppc_get_nominal_perf(9)
• cppc_get_highest_perf(9)
• cppc_get_epp_perf(9)
• cppc_get_perf_caps(9)
• cppc_perf_ctrs_in_pcc_cpu(9)
• cppc_perf_ctrs_in_pcc(9)
• cppc_get_perf_ctrs(9)
• cppc_set_epp(9)
• cppc_get_auto_act_window(9)
• cppc_set_auto_act_window(9)
• cppc_get_auto_sel(9)
• cppc_set_auto_sel(9)
• cppc_set_enable(9)
• cppc_get_perf(9)
• cppc_set_perf(9)
• cppc_get_perf_limited(9)
• cppc_set_perf_limited(9)
• cppc_get_transition_latency(9)

iykyk 😌💜

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ok real talk, go check those out if you wanna understand the whole CPPC/ACPI ecosystem — this page is just the one little memory-allocation bestie holding it down in ./drivers/acpi. 🧚‍♀️

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and that's the page, bestie! this one lives under ./drivers/acpi, comes to you from October 2026, and slays the pcc_data_alloc(9) era of the Kernel API Manual. mwah 💋🎀💖