From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-188.mta0.migadu.com (out-188.mta0.migadu.com [91.218.175.188]) (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 AD57F3B52EA for ; Thu, 26 Feb 2026 14:22:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.188 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772115763; cv=none; b=rkEWoI0gkcXpHFGyiMC/9uF6IbY9yrknGcT0+Xf3Zr+PH0PBecfTPBrUTNNpgOgCC/vsotlyKS8+QNql4bjFgYh7L7rkRQ+qDJCFTk5bV0VKiy1w4NX5ycggUZtQPQEXGAlvHJqWmYGJ/8U+opug4BMn3zKDBQoSi/wqU7o/52A= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772115763; c=relaxed/simple; bh=RceW3omtq+6jX7rEf3y6VHTawOLP6mPxHBdXOGE79IA=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=Fj+Qb6/kcGh/cWTNsgT3dz2yYRe/GXDV2u85oiTOU/nXcD1qWxLuouI8ZtkVzrgJAWhxEctgBKZFJc+n2EqObnw/hF+m+VmOpt+sHInwC2sXNH+iHMbuHqolFH+qF2PrLeC/oAFOYc8hS3ySE9RRLUXKsra5yA2IuCCB0uceuuk= 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=jKgAMrXK; arc=none smtp.client-ip=91.218.175.188 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="jKgAMrXK" 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 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: 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;