From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 5EFFE24BD03 for ; Tue, 19 Aug 2025 14:17:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755613025; cv=none; b=hXrocgaFutZZ3PtMwKyMDGvJX0BjTs/wHTORaLCT1bUTgUMIC7Vd45crKAPpA/mg5n74KmTzDnQDzqgDyClvwGi99lFCS7awuMBqzUYny4WsrqSLNqYcqvH97o6JVowar5BkDgIz/hthG/7JYHVgGdUIE31qLV9QznceYwDUNDw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755613025; c=relaxed/simple; bh=fIvuRJk9m8C5l+h2MFh0h7kc9zU68Ycc+a0H4sEdmMo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=NPC0ab6EXkcdEjXOYQB4QTdHs9mDIF6s0QnUFTUHlWK59dTnSVuYbS5gWmoLdNRiBM37XRok/sOpoWcE7Wbp4d/OpxoBvUHvLAA7JS2SPqy9CVY1khIsfIdGnvhJr426gbyxuAxCDf97oua55iougpW8UcDPzdiBKUFhQsEKWqM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=LX9wIL72; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="LX9wIL72" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1755613023; 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: in-reply-to:in-reply-to:references:references; bh=AyWTWLJP6DW1C6EfE8Dr/2WHmv98BO2UL0YW0p387dM=; b=LX9wIL729mZaqxqgGmCsb2DRI7XmBc2kaL+YRY21yFJzKpfDnE5CLE7OU2yu74qWLH2Ix/ HbA2wsa2WAEnK2td0q/kCknebsHv1Vco/zMyslqnVd7UJuePz1FtLXDfmKACdUT9yvM/K4 OPb8pKbS36HmB8K/gnlmyUmxoQ6XnTk= Received: from mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-97-WICi4W53MiWUgZ8wwI-hHQ-1; Tue, 19 Aug 2025 10:17:00 -0400 X-MC-Unique: WICi4W53MiWUgZ8wwI-hHQ-1 X-Mimecast-MFC-AGG-ID: WICi4W53MiWUgZ8wwI-hHQ_1755613012 Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 9BCDA188280A; Tue, 19 Aug 2025 14:16:50 +0000 (UTC) Received: from h1.redhat.com (unknown [10.22.64.137]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 4EBB019560BC; Tue, 19 Aug 2025 14:16:28 +0000 (UTC) From: Nico Pache To: linux-mm@kvack.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org Cc: david@redhat.com, ziy@nvidia.com, baolin.wang@linux.alibaba.com, lorenzo.stoakes@oracle.com, Liam.Howlett@oracle.com, ryan.roberts@arm.com, dev.jain@arm.com, corbet@lwn.net, rostedt@goodmis.org, mhiramat@kernel.org, mathieu.desnoyers@efficios.com, akpm@linux-foundation.org, baohua@kernel.org, willy@infradead.org, peterx@redhat.com, wangkefeng.wang@huawei.com, usamaarif642@gmail.com, sunnanyong@huawei.com, vishal.moola@gmail.com, thomas.hellstrom@linux.intel.com, yang@os.amperecomputing.com, kirill.shutemov@linux.intel.com, aarcange@redhat.com, raquini@redhat.com, anshuman.khandual@arm.com, catalin.marinas@arm.com, tiwai@suse.de, will@kernel.org, dave.hansen@linux.intel.com, jack@suse.cz, cl@gentwo.org, jglisse@google.com, surenb@google.com, zokeefe@google.com, hannes@cmpxchg.org, rientjes@google.com, mhocko@suse.com, rdunlap@infradead.org, hughd@google.com Subject: [PATCH v10 12/13] khugepaged: add per-order mTHP khugepaged stats Date: Tue, 19 Aug 2025 08:16:10 -0600 Message-ID: <20250819141610.626140-1-npache@redhat.com> In-Reply-To: <20250819134205.622806-1-npache@redhat.com> References: <20250819134205.622806-1-npache@redhat.com> Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 With mTHP support inplace, let add the per-order mTHP stats for exceeding NONE, SWAP, and SHARED. Signed-off-by: Nico Pache --- Documentation/admin-guide/mm/transhuge.rst | 17 +++++++++++++++++ include/linux/huge_mm.h | 3 +++ mm/huge_memory.c | 7 +++++++ mm/khugepaged.c | 16 +++++++++++++--- 4 files changed, 40 insertions(+), 3 deletions(-) diff --git a/Documentation/admin-guide/mm/transhuge.rst b/Documentation/admin-guide/mm/transhuge.rst index 7ccb93e22852..b85547ac4fe9 100644 --- a/Documentation/admin-guide/mm/transhuge.rst +++ b/Documentation/admin-guide/mm/transhuge.rst @@ -705,6 +705,23 @@ nr_anon_partially_mapped an anonymous THP as "partially mapped" and count it here, even though it is not actually partially mapped anymore. +collapse_exceed_swap_pte + The number of anonymous THP which contain at least one swap PTE. + Currently khugepaged does not support collapsing mTHP regions that + contain a swap PTE. + +collapse_exceed_none_pte + The number of anonymous THP which have exceeded the none PTE threshold. + With mTHP collapse, a bitmap is used to gather the state of a PMD region + and is then recursively checked from largest to smallest order against + the scaled max_ptes_none count. This counter indicates that the next + enabled order will be checked. + +collapse_exceed_shared_pte + The number of anonymous THP which contain at least one shared PTE. + Currently khugepaged does not support collapsing mTHP regions that + contain a shared PTE. + As the system ages, allocating huge pages may be expensive as the system uses memory compaction to copy data around memory to free a huge page for use. There are some counters in ``/proc/vmstat`` to help diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h index 4ada5d1f7297..6f1593d0b4b5 100644 --- a/include/linux/huge_mm.h +++ b/include/linux/huge_mm.h @@ -144,6 +144,9 @@ enum mthp_stat_item { MTHP_STAT_SPLIT_DEFERRED, MTHP_STAT_NR_ANON, MTHP_STAT_NR_ANON_PARTIALLY_MAPPED, + MTHP_STAT_COLLAPSE_EXCEED_SWAP, + MTHP_STAT_COLLAPSE_EXCEED_NONE, + MTHP_STAT_COLLAPSE_EXCEED_SHARED, __MTHP_STAT_COUNT }; diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 20d005c2c61f..9f0470c3e983 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -639,6 +639,10 @@ DEFINE_MTHP_STAT_ATTR(split_failed, MTHP_STAT_SPLIT_FAILED); DEFINE_MTHP_STAT_ATTR(split_deferred, MTHP_STAT_SPLIT_DEFERRED); DEFINE_MTHP_STAT_ATTR(nr_anon, MTHP_STAT_NR_ANON); DEFINE_MTHP_STAT_ATTR(nr_anon_partially_mapped, MTHP_STAT_NR_ANON_PARTIALLY_MAPPED); +DEFINE_MTHP_STAT_ATTR(collapse_exceed_swap_pte, MTHP_STAT_COLLAPSE_EXCEED_SWAP); +DEFINE_MTHP_STAT_ATTR(collapse_exceed_none_pte, MTHP_STAT_COLLAPSE_EXCEED_NONE); +DEFINE_MTHP_STAT_ATTR(collapse_exceed_shared_pte, MTHP_STAT_COLLAPSE_EXCEED_SHARED); + static struct attribute *anon_stats_attrs[] = { &anon_fault_alloc_attr.attr, @@ -655,6 +659,9 @@ static struct attribute *anon_stats_attrs[] = { &split_deferred_attr.attr, &nr_anon_attr.attr, &nr_anon_partially_mapped_attr.attr, + &collapse_exceed_swap_pte_attr.attr, + &collapse_exceed_none_pte_attr.attr, + &collapse_exceed_shared_pte_attr.attr, NULL, }; diff --git a/mm/khugepaged.c b/mm/khugepaged.c index c13bc583a368..5a3386043f39 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -594,7 +594,9 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma, continue; } else { result = SCAN_EXCEED_NONE_PTE; - count_vm_event(THP_SCAN_EXCEED_NONE_PTE); + if (order == HPAGE_PMD_ORDER) + count_vm_event(THP_SCAN_EXCEED_NONE_PTE); + count_mthp_stat(order, MTHP_STAT_COLLAPSE_EXCEED_NONE); goto out; } } @@ -633,10 +635,17 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma, * shared may cause a future higher order collapse on a * rescan of the same range. */ - if (order != HPAGE_PMD_ORDER || (cc->is_khugepaged && - shared > khugepaged_max_ptes_shared)) { + if (order != HPAGE_PMD_ORDER) { + result = SCAN_EXCEED_SHARED_PTE; + count_mthp_stat(order, MTHP_STAT_COLLAPSE_EXCEED_SHARED); + goto out; + } + + if (cc->is_khugepaged && + shared > khugepaged_max_ptes_shared) { result = SCAN_EXCEED_SHARED_PTE; count_vm_event(THP_SCAN_EXCEED_SHARED_PTE); + count_mthp_stat(order, MTHP_STAT_COLLAPSE_EXCEED_SHARED); goto out; } } @@ -1084,6 +1093,7 @@ static int __collapse_huge_page_swapin(struct mm_struct *mm, * range. */ if (order != HPAGE_PMD_ORDER) { + count_mthp_stat(order, MTHP_STAT_COLLAPSE_EXCEED_SWAP); pte_unmap(pte); mmap_read_unlock(mm); result = SCAN_EXCEED_SWAP_PTE; -- 2.50.1