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 lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 4B05AFCE08E for ; Thu, 26 Feb 2026 14:23:06 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [127.0.0.1]) by lists.ozlabs.org (Postfix) with ESMTP id 4fMDFh4HqPz2yFc; Fri, 27 Feb 2026 01:23:04 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; arc=none smtp.remote-ip=91.218.175.174 ARC-Seal: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1772115784; cv=none; b=ESgM5PQ3rbGf63tsWbGkUoTzW6r0m2TJQsaFtZowUDDN51fjsdIiktQzXM7SU3y8B153o23eoiR5g7JiCVS2q0aQnQUdMnJ7mwPM2cPJGC7akdcqgFbh1eMh7D+sefWBVpABvIk51QUapUPFkmu2+uxPDwcU9Kp3cXMiTtGK9TVqNUvGBxFsCDl5rCkKn+H85rlIjPQxFMgMPFUXNXST4msGAdhBcBfzsE4LKV/4BvItcOwALA4P8ODAFMB39/kehcxggU6cMRv6LDkcENm/1Pdq9Hmiw36kBKKwNFqUhhBV6osGMtqjZBo7y2fRXZ3DntsgPoC1Qr4Wg1XZGVtsDQ== ARC-Message-Signature: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1772115784; c=relaxed/relaxed; bh=jb9YPiWuPBlQARNsplGopujxVA0bSVtV2JHBgzvaymY=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=mBHKwXcm0DXDUq2mYKL9xlDIg6HYNEXfAbj3deiMjCLuyYvwyzFTIFEV7mxsDEQAsvOjv8mbeACSWLS7WMJYi+gNNrVadnj6Xl6DTjgvouwDkKsvX5DUFy4IvKVddDVPkwVikeynyJ1uNAFHF2LjrizTpSadugyZY701aY0VRXYooDbtG9ghis4CsLM4acHu6myGu9VGXURbW0RBvmPD3Swav/Vd2ocXPxA6eYl+1Gymbw2VNvwnA2p2HMElnePdo7I8FJa5lSCEeWw+kCQlnJtmKojHVwSk8fsnhlXyNySF+Dre2B/LeWtP5Alh2aHT1I6tKoRN+N8dlY1MiinZWA== ARC-Authentication-Results: i=1; lists.ozlabs.org; dmarc=pass (p=none dis=none) header.from=linux.dev; dkim=pass (1024-bit key; unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=jKgAMrXK; dkim-atps=neutral; spf=pass (client-ip=91.218.175.174; helo=out-174.mta0.migadu.com; envelope-from=usama.arif@linux.dev; receiver=lists.ozlabs.org) smtp.mailfrom=linux.dev Authentication-Results: lists.ozlabs.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: lists.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=jKgAMrXK; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=linux.dev (client-ip=91.218.175.174; helo=out-174.mta0.migadu.com; envelope-from=usama.arif@linux.dev; receiver=lists.ozlabs.org) Received: from out-174.mta0.migadu.com (out-174.mta0.migadu.com [91.218.175.174]) (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 lists.ozlabs.org (Postfix) with ESMTPS id 4fMDFd5llzz2xHX for ; Fri, 27 Feb 2026 01:23:00 +1100 (AEDT) Message-ID: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1772115759; 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=jb9YPiWuPBlQARNsplGopujxVA0bSVtV2JHBgzvaymY=; b=jKgAMrXKDp/fFQ5Qy0F4SHLZDHjfhKJDxbbLLtY+pveidJYQS4BwYY5icSGR6bqLh7c5yL dRolPPiOmwgxNE75HXCcD1jdE8X5lC5Ks2p9bLaV8lOOd+HsPb3Y+wLrYQFX6TZc3A8yHY 9Srq/4+a9GOfDAKt9fJHnlcntrkPyq0= Date: Thu, 26 Feb 2026 14:22:35 +0000 X-Mailing-List: linuxppc-dev@lists.ozlabs.org List-Id: List-Help: List-Owner: List-Post: List-Archive: , List-Subscribe: , , List-Unsubscribe: Precedence: list MIME-Version: 1.0 Subject: Re: [RFC v2 16/21] mm: thp: add THP_SPLIT_PMD_FAILED counter Content-Language: en-GB To: Andrew Morton , david@kernel.org, lorenzo.stoakes@oracle.com, willy@infradead.org, linux-mm@kvack.org Cc: fvdl@google.com, hannes@cmpxchg.org, riel@surriel.com, shakeel.butt@linux.dev, kas@kernel.org, baohua@kernel.org, dev.jain@arm.com, baolin.wang@linux.alibaba.com, npache@redhat.com, Liam.Howlett@oracle.com, ryan.roberts@arm.com, Vlastimil Babka , lance.yang@linux.dev, linux-kernel@vger.kernel.org, kernel-team@meta.com, maddy@linux.ibm.com, mpe@ellerman.id.au, linuxppc-dev@lists.ozlabs.org, hca@linux.ibm.com, gor@linux.ibm.com, agordeev@linux.ibm.com, borntraeger@linux.ibm.com, svens@linux.ibm.com, linux-s390@vger.kernel.org References: <20260226113233.3987674-1-usama.arif@linux.dev> <20260226113233.3987674-17-usama.arif@linux.dev> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Usama Arif In-Reply-To: <20260226113233.3987674-17-usama.arif@linux.dev> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT On 26/02/2026 11:23, Usama Arif wrote: > diff --git a/mm/rmap.c b/mm/rmap.c > index 2519d579bc1d8..2dae46fff08ae 100644 > --- a/mm/rmap.c > +++ b/mm/rmap.c > @@ -2067,8 +2067,10 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma, > pgtable_t pgtable = prealloc_pte; > > prealloc_pte = NULL; > + > if (!arch_needs_pgtable_deposit() && !pgtable && > vma_is_anonymous(vma)) { > + count_vm_event(THP_SPLIT_PMD_FAILED); > page_vma_mapped_walk_done(&pvmw); > ret = false; > break; > @@ -2471,6 +2473,7 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma, > prealloc_pte = NULL; > if (!arch_needs_pgtable_deposit() && !pgtable && > vma_is_anonymous(vma)) { > + count_vm_event(THP_SPLIT_PMD_FAILED); > page_vma_mapped_walk_done(&pvmw); > ret = false; > break; This will need to be guarded by CONFIG_TRANSPARENT_HUGEPAGE. Will need below diff in next series.. diff --git a/mm/rmap.c b/mm/rmap.c index 2dae46fff08ae..9d74600951cf6 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -2070,7 +2070,9 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma, if (!arch_needs_pgtable_deposit() && !pgtable && vma_is_anonymous(vma)) { +#if defined(CONFIG_TRANSPARENT_HUGEPAGE) count_vm_event(THP_SPLIT_PMD_FAILED); +#endif page_vma_mapped_walk_done(&pvmw); ret = false; break; @@ -2473,7 +2475,9 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma, prealloc_pte = NULL; if (!arch_needs_pgtable_deposit() && !pgtable && vma_is_anonymous(vma)) { +#if defined(CONFIG_TRANSPARENT_HUGEPAGE) count_vm_event(THP_SPLIT_PMD_FAILED); +#endif page_vma_mapped_walk_done(&pvmw); ret = false; break;