From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-182.mta1.migadu.com (mta1.migadu.com [37.59.57.117]) (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 7A15E23393C for ; Tue, 11 Aug 2026 12:49:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=37.59.57.117 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786452570; cv=none; b=P2BnPeJb8k7/g+x48UlaYHG55R5fzSaFWLYhAZ/bQDdO6q0+zwwJMlM+bxLQdA/SuJlYNuQrE4ryoBRfpw/1e2TsLQoBAMPEzTX86ezVCbd97HssuNkOX/jcgfOSPcFgPioQuEFE7jyhf9QzLpuf6a++aJwD6Y18aThRQ/61xHY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786452570; c=relaxed/simple; bh=Z3PB4X2OBZOkl/XgGCCvYNW3YfKW3AK94uc3wgOPwDA=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=W/LQsKvEQGSTe/8qeK+g3NawJ3VhNNE8hhoqcKZBtSXmrbg1MWHf/WlgSs+p7XvPHucpuy+0PvWcnWd3J7UVZzk5MFqYvNkzQDdEVcXLWnHZejgrd5QF59ZyNaUVB/LdSAG/lBc2EIgW9sX78EKsGXpB4ei11uNe1KDqOx7BUeY= 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=FgdY7UQX; arc=none smtp.client-ip=37.59.57.117 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="FgdY7UQX" 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=1786452566; 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=u47oBE0boWW/Z9dLtIXQCCcO1q1VmCr6ZGR13oxSM8M=; b=FgdY7UQX5jyHRSntUu1pa2fX7kXHK/7n4g3HTWKzTQpjBGwG+w/wrlSQSj49FudTxWFf+r XrMx6KwhrTRWa52ehzMVQuysYiE1aWwAs8vUq/QGgWH73ReM9iXo9obMgICamB7q/4+jC+ xkS0/ArToShMHtFz9eOiWyP4/ng0B18= From: "Nico Pache (Red Hat)" Date: Tue, 11 Aug 2026 06:48:35 -0600 Subject: [PATCH v4 3/7] mm/khugepaged: introduce a count_collapse_event() helper Precedence: bulk X-Mailing-List: linux-kernel@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: <20260811-khugepaged_pte_refactor-v4-3-ddac39d61c4a@linux.dev> References: <20260811-khugepaged_pte_refactor-v4-0-ddac39d61c4a@linux.dev> In-Reply-To: <20260811-khugepaged_pte_refactor-v4-0-ddac39d61c4a@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: David Hildenbrand (Arm) 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 8babd4c97db6..cae510aa2914 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -688,6 +688,14 @@ static inline bool folio_pte_referenced(struct folio *folio, return pte_young(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) @@ -708,9 +716,8 @@ 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; @@ -752,9 +759,8 @@ 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