From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 24EDFD2502F for ; Sun, 11 Jan 2026 12:19:51 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 8E6746B0092; Sun, 11 Jan 2026 07:19:50 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 87CFF6B0093; Sun, 11 Jan 2026 07:19:50 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7A8D76B0095; Sun, 11 Jan 2026 07:19:50 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 68E5C6B0092 for ; Sun, 11 Jan 2026 07:19:50 -0500 (EST) Received: from smtpin01.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 2FB471405BF for ; Sun, 11 Jan 2026 12:19:50 +0000 (UTC) X-FDA: 84319589340.01.885A68C Received: from mail-pj1-f49.google.com (mail-pj1-f49.google.com [209.85.216.49]) by imf03.hostedemail.com (Postfix) with ESMTP id 495FA20008 for ; Sun, 11 Jan 2026 12:19:48 +0000 (UTC) Authentication-Results: imf03.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b=kewTNYHz; spf=pass (imf03.hostedemail.com: domain of vernon2gm@gmail.com designates 209.85.216.49 as permitted sender) smtp.mailfrom=vernon2gm@gmail.com; dmarc=pass (policy=none) header.from=gmail.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1768133988; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=TXcEVyCz2mdgQ9fw8ki3ifTfwIPNt8/MvwZFlR641cE=; b=ivra6Lm9MH96fzDxo2Lpzy/YIQ+gne7vgBaAxZ04M52TJ/tuxjR4AXhsJNZmCA6JBeetfs aN0o/ZJl2PDdmhkqtux48/NgzWc39NPPfHnRkYawaBAZ9gvHJA0FXlE6TkAtmtdLqfMEd4 kr3waRNEW3P4Yes+RR5pgUUuRT7IRtU= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1768133988; a=rsa-sha256; cv=none; b=FTfh4HDCytC1Z7n63jNnQR3x0jexVfow6wo9lfsHtey0RFJX9GgISVwIZxELtzNldh/sA1 IOpCxxBZLYEkbtAT9k0Cbalonnhx2VWM3QHgYqZr2f0juWK3RZoxLSzrKYP+rzRO0U7kTS UlrSmZCxhG9eS41SjaJnd48q1Lmb/10= ARC-Authentication-Results: i=1; imf03.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b=kewTNYHz; spf=pass (imf03.hostedemail.com: domain of vernon2gm@gmail.com designates 209.85.216.49 as permitted sender) smtp.mailfrom=vernon2gm@gmail.com; dmarc=pass (policy=none) header.from=gmail.com Received: by mail-pj1-f49.google.com with SMTP id 98e67ed59e1d1-34c71f462d2so4735336a91.0 for ; Sun, 11 Jan 2026 04:19:48 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1768133987; x=1768738787; darn=kvack.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=TXcEVyCz2mdgQ9fw8ki3ifTfwIPNt8/MvwZFlR641cE=; b=kewTNYHzTvWvAWK8y/CQp8xP2j2AAc116kRwRpBQGzZpOIU6Ogh3mU3aXv4pKjBybT ItqoLqwxmeRkyjLpJPVqLEP/dP/nUrVZH8AO4JxVYMV4YrtNYngKEooFGKNzi4Ho74ZF 8t+qDe59tlhd//xi4SGaTuCPAeQYa8KZN04FvjmoB2k3c9y57OhhWrCFW3IGloh5yItq gbO34td01SYTOv/KD/BZQwVj+jckyr5TDTfrZTT5IQpKHERLUmlZzOKDIp/n0NZlmJ7K yOhHfH0Zu2vU+Y1BZm+OiRd029O3KOrh8ByRBs8pU7edKmDakPEDYu5IGLYWOBOHikd8 bDXQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1768133987; x=1768738787; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=TXcEVyCz2mdgQ9fw8ki3ifTfwIPNt8/MvwZFlR641cE=; b=P0SK3uimyinP8X6wHND0NtPc/ff8gh9skRPucIj2HUG2ajmO6SNM6oKdoiDYzfrmep rakd3G5vdnbtEpIinBwziRPsFtrg4KJgMR5l7XpTqqIUPS+V+9dtdlkmjZJvlRcTCgiJ ed6VcmqcMd8VUc2BguVjqTPZoYzR39NRJMas92KSfMbyCw9V1uhP8heHAzft6k52JoG4 Jv0NV3gQLS0h7LDV4Azjna6HZlEaL4jJy+dsAU99OvZZdMHy3IQELS6Bjwzb8UEQIO2a HRnchpbg86NLVIXw6ESAnhN4vDAqW7hW/EobODIhjzasPFboF8XpZNHcxdiUbVnV1YrH 3BBg== X-Forwarded-Encrypted: i=1; AJvYcCXYNrWRmV8hKOHEP8ifRatpIT6mJ36NSElW2V0HL3NxOutlahDu201wwCL7G/2DZePWUzAOMvRKhQ==@kvack.org X-Gm-Message-State: AOJu0Yzc7Z+7QOAmvskrzWB6Ld93IBNIXE3YVYKCh6W7xOMyr325BPl4 rrGQq88BLSU509Ucwj2gEJgUcBNadWIIjnr31eMBVgNm3xadLLge8pZk X-Gm-Gg: AY/fxX7ldX5P0PSWPCN8qoW22B/kD91Pps9fhX1ElKKiVCBfkwHIOoRGhibjhkkdSMI +E12U5SrDRIi+vpDP8ea5Mi7mvMT2emutiRCmWKx2rAymi7s4C88HMjOSGLoNGydbpFfi31BtJy NC9xbziSTlhUycZQz1S/rSqcdpal7SfvumlaBxMFEPazBlGRNG86dM8IPTUSxsGwnG8pvFc6JDd BY1u4d7JIU8zL1u19B+Cc+2+E7e34a2pg4MVFn2uq+NGakPMpwBBPHKntyLq0sak3vUvCjYeev7 e3lfwpsrQCLjnpaR4IXYpoCuxVjT8MPbE0dbLCjICI/yB+9HnCdZwMKnCQUjyQRzS8j0TODffuF sCki3N90TJ3XmUmb0Z0+j5KWpdy4Y9sycxFy2eAIXU1Yo2fXtcE1n5NbrCoGaIq7iscxC0K2Kj8 rriNzT37aFf7rcPeuyW4E2kCRyBglB1g== X-Google-Smtp-Source: AGHT+IGPJhW2ZDBzHgiDmQNFPVyqEA2J/ZIwwfVz+XH/ksrWs4Qx3T634999igMQa6zqSxteeK/3Ug== X-Received: by 2002:a17:90b:2711:b0:349:8184:af8b with SMTP id 98e67ed59e1d1-34f68c7a652mr15922912a91.7.1768133987030; Sun, 11 Jan 2026 04:19:47 -0800 (PST) Received: from localhost.localdomain ([221.227.246.159]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-34f6b07029fsm4877954a91.2.2026.01.11.04.19.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 11 Jan 2026 04:19:46 -0800 (PST) From: Vernon Yang X-Google-Original-From: Vernon Yang To: akpm@linux-foundation.org, david@kernel.org Cc: lorenzo.stoakes@oracle.com, ziy@nvidia.com, dev.jain@arm.com, baohua@kernel.org, lance.yang@linux.dev, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Vernon Yang Subject: [PATCH mm-new v4 2/6] mm: khugepaged: refine scan progress number Date: Sun, 11 Jan 2026 20:19:05 +0800 Message-ID: <20260111121909.8410-3-yanglincheng@kylinos.cn> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20260111121909.8410-1-yanglincheng@kylinos.cn> References: <20260111121909.8410-1-yanglincheng@kylinos.cn> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: 495FA20008 X-Rspam-User: X-Stat-Signature: gi3yak774ugu4btmdw6bufkxhxtdzxfe X-HE-Tag: 1768133988-648748 X-HE-Meta: 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 e3//dy7O qv2+ek21jG/kqlE6WRi8XgBCrT81BJgsVynxn+BxLqk5pmCrdxLR3+dnzHBSWeGqTWtUFARxXmJGI0HID/zh7NxDnYr+g9fPYuld8qP/9uJbhASRoCivbs/ZubhXU1QKL92cExApc19YHUe39bFUsZ0cLmD+sg9XcA1ldyt3G+0dxy+VGE6TUlIuVyCkBhN8cScEq9Pe7mSSiYujo/7nrgWm0seSiNjbrTK3/qvk4hDImAT1Lw9yZ0eF/vJW8Uk/U+jPeQ7CH8bUPbcuBqiEdf8zPS6koG/csWmKCC5BIjGeZkEmBQDW7EJNC7PP+N/uzgWMEMS92KYJSQ6cR6+fb94xwiHrzLw/4FRrY7FEhDFsd5TrhGhWFyfksCH7uZakXzsEzClFsmVLN1eDtapCUMse1R896Z1MFpmxuir2RGrylvRjtc6HxRcuW/w== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Currently, each scan always increases "progress" by HPAGE_PMD_NR, even if only scanning a single pte. This patch does not change the original semantics of "progress", it simply uses the exact number of PTEs counted to replace HPAGE_PMD_NR. Let me provide a detailed example: static int hpage_collapse_scan_pmd() { for (addr = start_addr, _pte = pte; _pte < pte + HPAGE_PMD_NR; _pte++, addr += PAGE_SIZE) { pte_t pteval = ptep_get(_pte); ... if (pte_uffd_wp(pteval)) { <-- first scan hit result = SCAN_PTE_UFFD_WP; goto out_unmap; } } } During the first scan, if pte_uffd_wp(pteval) is true, the loop exits directly. In practice, only one PTE is scanned before termination. Here, "progress += 1" reflects the actual number of PTEs scanned, but previously "progress += HPAGE_PMD_NR" always. Signed-off-by: Vernon Yang --- mm/khugepaged.c | 28 ++++++++++++++++++++++------ 1 file changed, 22 insertions(+), 6 deletions(-) diff --git a/mm/khugepaged.c b/mm/khugepaged.c index 2e570f83778c..5c6015ac7b5e 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -1249,6 +1249,7 @@ static enum scan_result collapse_huge_page(struct mm_struct *mm, unsigned long a static enum scan_result hpage_collapse_scan_pmd(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long start_addr, bool *mmap_locked, + int *cur_progress, struct collapse_control *cc) { pmd_t *pmd; @@ -1264,19 +1265,27 @@ static enum scan_result hpage_collapse_scan_pmd(struct mm_struct *mm, VM_BUG_ON(start_addr & ~HPAGE_PMD_MASK); result = find_pmd_or_thp_or_none(mm, start_addr, &pmd); - if (result != SCAN_SUCCEED) + if (result != SCAN_SUCCEED) { + if (cur_progress) + *cur_progress = HPAGE_PMD_NR; goto out; + } memset(cc->node_load, 0, sizeof(cc->node_load)); nodes_clear(cc->alloc_nmask); pte = pte_offset_map_lock(mm, pmd, start_addr, &ptl); if (!pte) { + if (cur_progress) + *cur_progress = HPAGE_PMD_NR; result = SCAN_NO_PTE_TABLE; goto out; } for (addr = start_addr, _pte = pte; _pte < pte + HPAGE_PMD_NR; _pte++, addr += PAGE_SIZE) { + if (cur_progress) + *cur_progress += 1; + pte_t pteval = ptep_get(_pte); if (pte_none_or_zero(pteval)) { ++none_or_zero; @@ -2297,6 +2306,7 @@ static enum scan_result collapse_file(struct mm_struct *mm, unsigned long addr, static enum scan_result hpage_collapse_scan_file(struct mm_struct *mm, unsigned long addr, struct file *file, pgoff_t start, + int *cur_progress, struct collapse_control *cc) { struct folio *folio = NULL; @@ -2337,6 +2347,9 @@ static enum scan_result hpage_collapse_scan_file(struct mm_struct *mm, unsigned continue; } + if (cur_progress) + *cur_progress += folio_nr_pages(folio); + if (folio_order(folio) == HPAGE_PMD_ORDER && folio->index == start) { /* Maybe PMD-mapped */ @@ -2466,6 +2479,7 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages, enum scan_result while (khugepaged_scan.address < hend) { bool mmap_locked = true; + int cur_progress = 0; cond_resched(); if (unlikely(hpage_collapse_test_exit_or_disable(mm))) @@ -2482,7 +2496,8 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages, enum scan_result mmap_read_unlock(mm); mmap_locked = false; *result = hpage_collapse_scan_file(mm, - khugepaged_scan.address, file, pgoff, cc); + khugepaged_scan.address, file, pgoff, + &cur_progress, cc); fput(file); if (*result == SCAN_PTE_MAPPED_HUGEPAGE) { mmap_read_lock(mm); @@ -2496,7 +2511,8 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages, enum scan_result } } else { *result = hpage_collapse_scan_pmd(mm, vma, - khugepaged_scan.address, &mmap_locked, cc); + khugepaged_scan.address, &mmap_locked, + &cur_progress, cc); } if (*result == SCAN_SUCCEED) @@ -2504,7 +2520,7 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages, enum scan_result /* move to next address */ khugepaged_scan.address += HPAGE_PMD_SIZE; - progress += HPAGE_PMD_NR; + progress += cur_progress; if (!mmap_locked) /* * We released mmap_lock so break loop. Note @@ -2826,11 +2842,11 @@ int madvise_collapse(struct vm_area_struct *vma, unsigned long start, mmap_read_unlock(mm); mmap_locked = false; result = hpage_collapse_scan_file(mm, addr, file, pgoff, - cc); + NULL, cc); fput(file); } else { result = hpage_collapse_scan_pmd(mm, vma, addr, - &mmap_locked, cc); + &mmap_locked, NULL, cc); } if (!mmap_locked) *lock_dropped = true; -- 2.51.0