From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-186.mta0.migadu.com (out-186.mta0.migadu.com [91.218.175.186]) (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 799AF3B8930 for ; Tue, 4 Aug 2026 19:25:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.186 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785871535; cv=none; b=Snkss/YPtUjmYWtQmWHYdIK4rJhM6H0R5fqrqmfVm7NIdy14HcF7gdS42MM54GJE6QKxnjqLboOy+/t+8OP6gVuo5rgMoMn7kxWjr4GXn47e/lcC9Wq2iq2tDHvlkixCLF/XyD6yW6W5uS9QMubicU2TiLHmTysJMgFxv/7Lp2c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785871535; c=relaxed/simple; bh=C9KrXbUFI/wTtvIMDZPEqxUqUQDs+7HwRf1I3BaFkk0=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=q0w2dAQnAgEDiQ1DDIS344Q829YyJcbBbTyGXzxdlu6xxjIrsx+Qor9Jl8riesngwoIMUOtnS11m33rKIFfp/BskK/RR0YQ7PUZpIhR8Kd0V1aj7Utm82P//E66UFFLk0J9DFmmK81ztEbsxhcEvTfassXAYEykV3KI+vpWO6w0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=u2G6hqEi; arc=none smtp.client-ip=91.218.175.186 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="u2G6hqEi" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1785871531; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=geBTcCptRliUmzhkX/SVMpzDuh58iStAuLW+HnKYxWU=; b=u2G6hqEi51nhf0mr0uDzHxvKicocCqA6MAzaVDI4UjoE1Ie6BmiaQpyPM/o6o0cAU4xnKi Ou0JgTb+njRMLuI2VrHhPphBJrcIf3hd3lWV0/VwUHHFcLtPVpZNBc55Xum4DioltpPCd+ mTeeHNr4k6j0TzYke7FIaxBSitAhOzc= From: "Nico Pache (Red Hat)" Date: Tue, 04 Aug 2026 13:25:01 -0600 Subject: [PATCH v3 3/7] mm/khugepaged: introduce a count_collapse_event() helper Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260804-khugepaged_pte_refactor-v3-3-0364cad642a0@linux.dev> References: <20260804-khugepaged_pte_refactor-v3-0-0364cad642a0@linux.dev> In-Reply-To: <20260804-khugepaged_pte_refactor-v3-0-0364cad642a0@linux.dev> To: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org Cc: Andrew Morton , David Hildenbrand , Lorenzo Stoakes , Zi Yan , Baolin Wang , "Liam R. Howlett" , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Usama Arif , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Jonathan Corbet , Shuah Khan , "Nico Pache (Red Hat)" X-Migadu-Flow: FLOW_OUT Provide a simple helper function to help reduce a often used, and duplicate pattern across the khugepaged code. When collapsing to a PMD we need to record a vm_event and the mTHP_stat event. When doing mTHP collapse we only update the mTHP stat. Reviewed-by: Baolin Wang Acked-by: Usama Arif Signed-off-by: Nico Pache (Red Hat) --- mm/khugepaged.c | 42 +++++++++++++++++++++--------------------- 1 file changed, 21 insertions(+), 21 deletions(-) diff --git a/mm/khugepaged.c b/mm/khugepaged.c index 9b15c1740943..a2691587a510 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -689,6 +689,14 @@ static inline bool pte_is_referenced(struct collapse_control *cc, pte_t pteval, mmu_notifier_test_young(vma->vm_mm, addr)); } +static void count_collapse_event(unsigned int order, enum vm_event_item vm_event, + enum mthp_stat_item mthp_event) +{ + if (is_pmd_order(order)) + count_vm_event(vm_event); + count_mthp_stat(order, mthp_event); +} + static enum scan_result __collapse_huge_page_isolate(struct vm_area_struct *vma, unsigned long start_addr, pte_t *pte, struct collapse_control *cc, unsigned int order, struct list_head *compound_pagelist) @@ -709,9 +717,8 @@ static enum scan_result __collapse_huge_page_isolate(struct vm_area_struct *vma, if (pte_none_or_zero(pteval)) { if (++none_or_zero > max_ptes_none) { result = SCAN_EXCEED_NONE_PTE; - if (is_pmd_order(order)) - count_vm_event(THP_SCAN_EXCEED_NONE_PTE); - count_mthp_stat(order, MTHP_STAT_COLLAPSE_EXCEED_NONE); + count_collapse_event(order, THP_SCAN_EXCEED_NONE_PTE, + MTHP_STAT_COLLAPSE_EXCEED_NONE); goto out; } continue; @@ -753,9 +760,8 @@ static enum scan_result __collapse_huge_page_isolate(struct vm_area_struct *vma, */ if (++shared > max_ptes_shared) { result = SCAN_EXCEED_SHARED_PTE; - if (is_pmd_order(order)) - count_vm_event(THP_SCAN_EXCEED_SHARED_PTE); - count_mthp_stat(order, MTHP_STAT_COLLAPSE_EXCEED_SHARED); + count_collapse_event(order, THP_SCAN_EXCEED_SHARED_PTE, + MTHP_STAT_COLLAPSE_EXCEED_SHARED); goto out; } } @@ -1264,15 +1270,12 @@ static enum scan_result alloc_charge_folio(struct folio **foliop, struct mm_stru folio = __folio_alloc(gfp, order, node, &cc->alloc_nmask); if (!folio) { *foliop = NULL; - if (is_pmd_order(order)) - count_vm_event(THP_COLLAPSE_ALLOC_FAILED); - count_mthp_stat(order, MTHP_STAT_COLLAPSE_ALLOC_FAILED); + count_collapse_event(order, THP_COLLAPSE_ALLOC_FAILED, + MTHP_STAT_COLLAPSE_ALLOC_FAILED); return SCAN_ALLOC_HUGE_PAGE_FAIL; } - if (is_pmd_order(order)) - count_vm_event(THP_COLLAPSE_ALLOC); - count_mthp_stat(order, MTHP_STAT_COLLAPSE_ALLOC); + count_collapse_event(order, THP_COLLAPSE_ALLOC, MTHP_STAT_COLLAPSE_ALLOC); if (unlikely(mem_cgroup_charge(folio, mm, gfp))) { folio_put(folio); @@ -1662,9 +1665,8 @@ static enum scan_result collapse_scan_pmd(struct mm_struct *mm, if (pte_none_or_zero(pteval)) { if (++none_or_zero > max_ptes_none) { result = SCAN_EXCEED_NONE_PTE; - count_vm_event(THP_SCAN_EXCEED_NONE_PTE); - count_mthp_stat(HPAGE_PMD_ORDER, - MTHP_STAT_COLLAPSE_EXCEED_NONE); + count_collapse_event(HPAGE_PMD_ORDER, THP_SCAN_EXCEED_NONE_PTE, + MTHP_STAT_COLLAPSE_EXCEED_NONE); goto out_unmap; } continue; @@ -1672,9 +1674,8 @@ static enum scan_result collapse_scan_pmd(struct mm_struct *mm, if (!pte_present(pteval)) { if (++unmapped > max_ptes_swap) { result = SCAN_EXCEED_SWAP_PTE; - count_vm_event(THP_SCAN_EXCEED_SWAP_PTE); - count_mthp_stat(HPAGE_PMD_ORDER, - MTHP_STAT_COLLAPSE_EXCEED_SWAP); + count_collapse_event(HPAGE_PMD_ORDER, THP_SCAN_EXCEED_SWAP_PTE, + MTHP_STAT_COLLAPSE_EXCEED_SWAP); goto out_unmap; } /* @@ -1731,9 +1732,8 @@ static enum scan_result collapse_scan_pmd(struct mm_struct *mm, if (folio_maybe_mapped_shared(folio)) { if (++shared > max_ptes_shared) { result = SCAN_EXCEED_SHARED_PTE; - count_vm_event(THP_SCAN_EXCEED_SHARED_PTE); - count_mthp_stat(HPAGE_PMD_ORDER, - MTHP_STAT_COLLAPSE_EXCEED_SHARED); + count_collapse_event(HPAGE_PMD_ORDER, THP_SCAN_EXCEED_SHARED_PTE, + MTHP_STAT_COLLAPSE_EXCEED_SHARED); goto out_unmap; } } -- 2.55.0