pt_clear_entries(9)

💅 pt_clear_entries — a Kernel API Manual moment

okay so bestie, we're in the kernel API manual, and today's main character is pt_clear_entries(9). she's a void function, she returns nothing, and she's here to hand you a freshly emptied run of page-table entries. no cap. ✨

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🌸 NAME 🌸

pt_clear_entries — makes entries empty (non-present). literally just yeets the contents and leaves you with a blank slate, iykyk 🫶

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🎀 SYNOPSIS 🎀

void pt_clear_entries (struct pt_state *pts , unsigned int
num_contig_lg2 );

bestie look at her. void return, two args, no notes. 👑

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🦋 ARGUMENTS 🦋

• pts — the starting table index 💖 like, where the clearing begins. that's the vibe.
• num_contig_lg2 — the number of contiguous items to clear 🌈 (yes it's log2-flavored, the name is telling you that itself, we love a self-documenting parameter).

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🧚 DESCRIPTION 🧚

so what does she actually do? she clears a run of entries. that's it, that's the whole gig. 🔥

here's the part that matters though — a cleared entry will load back as PT_ENTRY_EMPTY, and it does not have any effect on table walking. so the walker just strolls right past it like it's not even there. iconic behavior honestly. 💀

⚠️ okay this is the important bit, don't skip it: the starting index must be aligned to num_contig_lg2. like, that's a hard requirement, not a suggestion. misaligned starting index? that's a you problem, bestie. 😭

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⭐ SEE ALSO ⭐

the kernel file lives at ./drivers/iommu/generic_pt/pt_common.h — that's the whole squad's hangout spot 💜

and here's the full friend group, go say hi:

• pt_attr_from_entry(9)
• pt_can_have_leaf(9)
• pt_can_have_table(9)
• pt_entry_make_write_dirty(9)
• pt_entry_make_write_clean(9)
• pt_entry_is_write_dirty(9)
• pt_dirty_supported(9)
• pt_entry_num_contig_lg2(9)
• pt_entry_oa(9)
• pt_entry_oa_lg2sz(9)
• pt_entry_oa_exact(9)
• pt_full_va_prefix(9)
• pt_has_system_page_size(9)
• pt_install_leaf_entry(9)
• pt_install_table(9)
• pt_item_oa(9)
• pt_load_entry_raw(9)
• pt_max_oa_lg2(9)
• pt_num_items_lg2(9)
• pt_pgsz_lg2_to_level(9)
• pt_possible_sizes(9)
• pt_table_item_lg2sz(9)
• pt_table_oa_lg2sz(9)
• pt_table_pa(9)
• pt_table_ptr(9)
• pt_max_sw_bit(9)
• pt_test_sw_bit_acquire(9)
• pt_set_sw_bit_release(9)
• pt_load_entry(9)

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and that's the page, bestie 🎀 this whole thing ships out of ./drivers/iommu/generic_pt and it's dated October 2026 — so yeah, she's from the future, we stan a forward-thinking queen. periodt. 💅✨