From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-171.mta0.migadu.com (out-171.mta0.migadu.com [91.218.175.171]) (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 2356A2FD69A for ; Wed, 15 Jul 2026 06:22:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.171 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784096528; cv=none; b=NDYybt0jpOvDT9pm/snQHlsK8fUvBiLQSFsAXbht3fK3LFXFTuBPgNqVIq1L0lkm9cefLWr1l9t9Kzs0XsKEgeQhS5JXAa7q2sYYStflQA3HOnYXBddQn71gcv836ARNP9ITAfLVFWTVjX5YxWYXhgVKhSV/vKDp3S+2JwjXpKI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784096528; c=relaxed/simple; bh=9s9v3FFpioUADExen8jnQnpehBWz643Fcs14xODkY9A=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=iAANAsVzXLoEj0B5g1cJnfWRr5251GDcR19c2pc5gIbNfM+MwYDKw3rQ5t7ERq5TBpqbgsPr1Et/2TFq64fHK9OQYzLgmnfSASLE1o8JtYBfb2okFI+oz+tAM3T0zf65NYAPMF7PmQh/0Vh/PVbp3/VC1qy3izl/ewKag1irK60= 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=XPPDoyqE; arc=none smtp.client-ip=91.218.175.171 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="XPPDoyqE" 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=1784096524; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=aAFhDqjKlrdLoyRX5Ba32oyx14stfmQIpQ5GnCFRx88=; b=XPPDoyqEiL4pLZweZiL7WIIYM0vNWGZvhuduNYlL5+L7HdkMekCQkS7tz8QR6NtqZqhQQO GvJDsZaPLD27kye1PPfcXvSyS5WrbqfLnHhRz1OP4sTpozKJ945TVnwdmhzFmkn6I3Nm3w /jTU7p3xB8tT9uMG5id+urAN3kY0f9Y= From: Ye Liu To: Andrew Morton , David Hildenbrand , Lorenzo Stoakes Cc: Ye Liu , Zi Yan , Baolin Wang , "Liam R. Howlett" , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Usama Arif , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH] mm/thp: support mTHP in thp_underused() Date: Wed, 15 Jul 2026 14:21:49 +0800 Message-ID: <20260715062150.114757-1-ye.liu@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT From: Ye Liu When khugepaged_max_ptes_none is configured to a non-default value, scale it for non-PMD-mappable folios to match the logic in collapse_max_ptes_none(), so mTHP can be classified as underused instead of being silently skipped due to unscaled PMD-sized thresholds. Signed-off-by: Ye Liu --- mm/huge_memory.c | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 25612af72dca..c642bec967fa 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -4489,24 +4489,29 @@ static unsigned long deferred_split_count(struct shrinker *shrink, static bool thp_underused(struct folio *folio) { int num_zero_pages = 0, num_filled_pages = 0; + unsigned int max_ptes_none = khugepaged_max_ptes_none; + unsigned int folio_nr = folio_nr_pages(folio); int i; - if (khugepaged_max_ptes_none == HPAGE_PMD_NR - 1) + if (!folio_test_pmd_mappable(folio)) { + if (max_ptes_none == HPAGE_PMD_NR - 1) + max_ptes_none = folio_nr - 1; + else if (max_ptes_none) + return false; + } + + if (max_ptes_none == folio_nr - 1) return false; if (folio_contain_hwpoisoned_page(folio)) return false; - for (i = 0; i < folio_nr_pages(folio); i++) { + for (i = 0; i < folio_nr; i++) { if (pages_identical(folio_page(folio, i), ZERO_PAGE(0))) { - if (++num_zero_pages > khugepaged_max_ptes_none) + if (++num_zero_pages > max_ptes_none) return true; } else { - /* - * Another path for early exit once the number - * of non-zero filled pages exceeds threshold. - */ - if (++num_filled_pages >= HPAGE_PMD_NR - khugepaged_max_ptes_none) + if (++num_filled_pages >= folio_nr - max_ptes_none) return false; } } -- 2.43.0