From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 973784B4864 for ; Wed, 16 Sep 2026 22:48:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789598940; cv=none; b=lojwpc/qBcMG+ppFaEdA06/8yUe9iXo67RrWEG/IF9XDjsZsAD2jECCRRnh5NDeNchku7WV0GmN0Tq/5dvy3U5v1TiD5SPnEdWSJAhIQySMQWt4+fbQeUA4KO1h87drfqRFGs3ySdGyIiAtOf6Trmak5bhw5GQs/4KNChXvVAYs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789598940; c=relaxed/simple; bh=73Nb1VTdf3hVEVQPK4VaYNsVpRKM8sb1jRchVjuVhsc=; h=Date:To:From:Subject:Message-Id; b=tKjzyzVCMJ0rKxH/g3dvtkftDBw0/Am9mmrJ89FpYxwbtTLETU6ZHKRAGK/Hrl0ojo7md00TYlAHfcKL4QMysBGIGFq1l6lDulMkEQ64IXoQVwsalBpeHpGOIdJiBp3lV2/23SafDUKncRLt4mXdyRlTH120Gzkub5Ul2uscI5g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=zFrSFTSz; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="zFrSFTSz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E314F1F00899; Wed, 16 Sep 2026 22:48:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1789598929; bh=ZKCG2MJv2FXOm4aGaD0LdiVBF48c+FzfgT/joYuf4lQ=; h=Date:To:From:Subject; b=zFrSFTSznkZ0tHzR7oRIgeLM7DYX4xb6tgEU2ZGH2bjZTOMQo5XQVldJogFCC9Fv4 KciTh/ZwzxovzuCyFV+2BV6n8++VRko+/enodVSOhx2WfpGbEvZLq8DewzjPvTG4Vq JzK/JD6rcOhzYz6ebuyojnp9VjZhwo0l4OR4XyHU= Date: Wed, 16 Sep 2026 15:48:48 -0700 To: mm-commits@vger.kernel.org,kas@kernel.org,akpm@linux-foundation.org From: Andrew Morton Subject: + mm-khugepaged-rename-mthp_present_ptes-bitmap-to-eligible_ptes.patch added to mm-unstable branch Message-Id: <20260916224848.E314F1F00899@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: mm/khugepaged: rename mthp_present_ptes bitmap to eligible_ptes has been added to the -mm mm-unstable branch. Its filename is mm-khugepaged-rename-mthp_present_ptes-bitmap-to-eligible_ptes.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-khugepaged-rename-mthp_present_ptes-bitmap-to-eligible_ptes.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via various branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there most days ------------------------------------------------------ From: "Kiryl Shutsemau (Meta)" Subject: mm/khugepaged: rename mthp_present_ptes bitmap to eligible_ptes Date: Wed, 16 Sep 2026 10:31:30 +0100 The name says less than the bit means. A set bit means not only that the PTE is present, but also that it passed the other checks: uffd, lazyfree, anonymity, sharing. The PTE can be considered a collapse source. mthp_collapse() then reads the bitmap starting at the PMD order, so the bitmap is not specific to mTHP either. Name it for what a set bit means, and update the comments that named it. No functional change. Assisted-by: LLM Link: https://lore.kernel.org/20260916093145.4022188-4-kirill@shutemov.name Signed-off-by: Kiryl Shutsemau (Meta) Signed-off-by: Andrew Morton Reviewed-by: Zi Yan Reviewed-by: Baolin Wang Cc: Barry Song Cc: David Hildenbrand Cc: Dev Jain Cc: Jann Horn Cc: Lance Yang Cc: Liam R. Howlett Cc: Lorenzo Stoakes Cc: Ryan Roberts Cc: Vlastimil Babka --- mm/khugepaged.c | 32 ++++++++++++++++---------------- 1 file changed, 16 insertions(+), 16 deletions(-) --- a/mm/khugepaged.c~mm-khugepaged-rename-mthp_present_ptes-bitmap-to-eligible_ptes +++ a/mm/khugepaged.c @@ -115,8 +115,8 @@ struct collapse_control { /* nodemask for allocation fallback */ nodemask_t alloc_nmask; - /* Each bit represents a single occupied (!none/zero) page. */ - DECLARE_BITMAP(mthp_present_ptes, MAX_PTRS_PER_PTE); + /* Each bit marks a PTE the scan accepted as a collapse source */ + DECLARE_BITMAP(eligible_ptes, MAX_PTRS_PER_PTE); }; /** @@ -627,7 +627,7 @@ static void collapse_control_init_scan(s { memset(cc->node_load, 0, sizeof(cc->node_load)); nodes_clear(cc->alloc_nmask); - bitmap_zero(cc->mthp_present_ptes, MAX_PTRS_PER_PTE); + bitmap_zero(cc->eligible_ptes, MAX_PTRS_PER_PTE); } static void release_pte_folio(struct folio *folio) @@ -1482,15 +1482,15 @@ static unsigned int max_order_from_offse * mthp_collapse() consumes the bitmap that is generated during * collapse_scan_pmd() to determine what regions and mTHP orders fit best. * - * Each bit in cc->mthp_present_ptes represents a single occupied (!none/zero) - * page. We start at the PMD order and check if it is eligible for collapse; + * Each bit in cc->eligible_ptes marks a PTE the scan accepted as a collapse + * source. We start at the PMD order and check if it is eligible for collapse; * if not, we check the left and right halves of the PTE page table we are * examining at a lower order. * - * For each of these, we determine how many PTE entries are occupied in the - * range of PTE entries we propose to collapse, then we compare this to a - * threshold number of PTE entries which would need to be occupied for a - * collapse to be permitted at that order (accounting for max_ptes_none). + * For each of these, we count the eligible PTEs in the range we propose to + * collapse, then we compare this to the number of eligible PTEs the range + * would need for a collapse to be permitted at that order (accounting for + * max_ptes_none). * * If a collapse is permitted, we attempt to collapse the PTE range into a * mTHP. @@ -1499,7 +1499,7 @@ static enum scan_result mthp_collapse(st unsigned long address, int referenced, int unmapped, struct collapse_control *cc, unsigned long enabled_orders) { - unsigned int nr_occupied_ptes, nr_ptes, max_ptes_none; + unsigned int nr_eligible_ptes, nr_ptes, max_ptes_none; enum scan_result last_result = SCAN_FAIL; int collapsed = 0; bool alloc_failed = false; @@ -1514,18 +1514,18 @@ static enum scan_result mthp_collapse(st goto next_order; max_ptes_none = collapse_max_ptes_none(cc, NULL, order); - nr_occupied_ptes = bitmap_weight_from(cc->mthp_present_ptes, offset, + nr_eligible_ptes = bitmap_weight_from(cc->eligible_ptes, offset, offset + nr_ptes); /* * Swap PTEs accepted during the scan are counted in @unmapped, - * not in the present-PTE bitmap. Account them for the PMD-order + * not in cc->eligible_ptes. Account them for the PMD-order * candidate. */ if (is_pmd_order(order)) - nr_occupied_ptes += unmapped; + nr_eligible_ptes += unmapped; - if (nr_occupied_ptes >= nr_ptes - max_ptes_none) { + if (nr_eligible_ptes >= nr_ptes - max_ptes_none) { enum scan_result ret; collapse_address = address + offset * PAGE_SIZE; @@ -1731,8 +1731,8 @@ static enum scan_result collapse_scan_pm } } - /* Set bit for occupied pages */ - __set_bit(i, cc->mthp_present_ptes); + /* The scan accepted this PTE as a collapse source */ + __set_bit(i, cc->eligible_ptes); /* * Record which node the original page is from and save this * information to cc->node_load[]. _ Patches currently in -mm which might be from kas@kernel.org are mm-huge_memory-do-not-touch-frozen-folios-in-deferred_split_isolate.patch mm-huge_memory-dequeue-the-deferred-split-after-the-split-freeze.patch mm-huge_memory-add-folio_reset_partially_mapped.patch mm-khugepaged-drop-redundant-mm_struct-pin-in-madvise_collapse.patch mm-khugepaged-count-collapses-where-khugepaged-makes-them.patch mm-khugepaged-rename-mthp_present_ptes-bitmap-to-eligible_ptes.patch mm-collapse-add-collapseh-for-the-collapse-interface.patch mm-collapse-state-what-a-collapse-may-do-in-the-policy.patch mm-collapse-drop-the-collapse_possible-wrapper.patch mm-collapse-name-the-per-table-scan-reset-for-what-it-resets.patch mm-collapse-separate-scanning-a-pte-table-from-collapsing-it.patch mm-collapse-open-code-collapse_single_pmd-in-its-two-callers.patch mm-collapse-work-out-the-orders-a-vma-allows-once-per-vma.patch mm-collapse-declare-the-collapse-interface-in-collapseh.patch mm-collapse-implement-madv_collapse-in-madvisec.patch