From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out30-111.freemail.mail.aliyun.com (out30-111.freemail.mail.aliyun.com [115.124.30.111]) (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 8D00727EFE3; Fri, 12 Sep 2025 09:24:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.111 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757669101; cv=none; b=pn7SlpOXJ+T5MHoCPSjTttvD4Cj3uaUPCNrG8Qcf4hTbdfn1//Yx74YCfQlfjzkCmjOPf1iexa+KhlFARhQKtx3mDCVwni8XV0isdU4pE4cw78mtSjHir+odK9yqtxVbImwdozCl820eS3BWuBzQoEyVug6YSdycsXY1L8LZK9A= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757669101; c=relaxed/simple; bh=GmEAPbFMXpczpVM7DQb8d28PRbScKAo5q6THwLy4XlM=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=d2AqHL2w2cUPLiLLEt9f46h7dxrdBaGwfGIRQHiNiBbYZII5OvfAx/VChP7qdLYm9PG8LiJ3bgHkvXDezc2SrDWhvYo9wbZuoN/YVw2dfL87kXVLEpPyGnZCOKtKZvQv8I5BndGdFqFEFSdGlEaJcjOg6y3ooJ0th/AWbdnLeqw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=FC5rw6ix; arc=none smtp.client-ip=115.124.30.111 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="FC5rw6ix" DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1757669095; h=Message-ID:Date:MIME-Version:Subject:To:From:Content-Type; bh=yeQuxM0fjpmIe4g0xUTHddlrE41HXqCqb25Ih/uw2qU=; b=FC5rw6ixR5LazE+N3z4/dTcrJQMWug331XVyZltsj007wwaIMcbYk1MIz7HngLF0s48iJ7+quRnMaADJDkw5FAgDSKcC/7EV7t1PcFZAU7rVMv77wrKs5veqVYDtymV6+emOeD/vU/Fp/dzr9mc5ojNrdmEOPVrDVkd25W2SiMw= Received: from 30.74.144.122(mailfrom:baolin.wang@linux.alibaba.com fp:SMTPD_---0WnqpgPM_1757669090 cluster:ay36) by smtp.aliyun-inc.com; Fri, 12 Sep 2025 17:24:52 +0800 Message-ID: <50305e9f-ad03-4ce9-9ae7-0c657bd87ef0@linux.alibaba.com> Date: Fri, 12 Sep 2025 17:24:50 +0800 Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v11 11/15] khugepaged: introduce collapse_allowable_orders helper function To: Nico Pache , 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, 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, kas@kernel.org, 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, richard.weiyang@gmail.com, lance.yang@linux.dev, vbabka@suse.cz, rppt@kernel.org, jannh@google.com, pfalcato@suse.de References: <20250912032810.197475-1-npache@redhat.com> <20250912032810.197475-12-npache@redhat.com> From: Baolin Wang In-Reply-To: <20250912032810.197475-12-npache@redhat.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 2025/9/12 11:28, Nico Pache wrote: > Add collapse_allowable_orders() to generalize THP order eligibility. The > function determines which THP orders are permitted based on collapse > context (khugepaged vs madv_collapse). > > This consolidates collapse configuration logic and provides a clean > interface for future mTHP collapse support where the orders may be > different. > > Signed-off-by: Nico Pache LGTM. Reviewed-by: Baolin Wang > --- > mm/khugepaged.c | 15 ++++++++++++--- > 1 file changed, 12 insertions(+), 3 deletions(-) > > diff --git a/mm/khugepaged.c b/mm/khugepaged.c > index 5b45ef575446..d224fa97281a 100644 > --- a/mm/khugepaged.c > +++ b/mm/khugepaged.c > @@ -485,7 +485,16 @@ static int collapse_max_ptes_none(unsigned int order) > else > max_ptes_none = khugepaged_max_ptes_none; > return max_ptes_none >> (HPAGE_PMD_ORDER - order); > +} > + > +/* Check what orders are allowed based on the vma and collapse type */ > +static unsigned long collapse_allowable_orders(struct vm_area_struct *vma, > + vm_flags_t vm_flags, bool is_khugepaged) > +{ > + enum tva_type tva_flags = is_khugepaged ? TVA_KHUGEPAGED : TVA_FORCED_COLLAPSE; > + unsigned long orders = BIT(HPAGE_PMD_ORDER); > > + return thp_vma_allowable_orders(vma, vm_flags, tva_flags, orders); > } > > void khugepaged_enter_vma(struct vm_area_struct *vma, > @@ -493,7 +502,7 @@ void khugepaged_enter_vma(struct vm_area_struct *vma, > { > if (!mm_flags_test(MMF_VM_HUGEPAGE, vma->vm_mm) && > hugepage_pmd_enabled()) { > - if (thp_vma_allowable_order(vma, vm_flags, TVA_KHUGEPAGED, PMD_ORDER)) > + if (collapse_allowable_orders(vma, vm_flags, true)) > __khugepaged_enter(vma->vm_mm); > } > } > @@ -2557,7 +2566,7 @@ static unsigned int collapse_scan_mm_slot(unsigned int pages, int *result, > progress++; > break; > } > - if (!thp_vma_allowable_order(vma, vma->vm_flags, TVA_KHUGEPAGED, PMD_ORDER)) { > + if (!collapse_allowable_orders(vma, vma->vm_flags, true)) { > skip: > progress++; > continue; > @@ -2865,7 +2874,7 @@ int madvise_collapse(struct vm_area_struct *vma, unsigned long start, > BUG_ON(vma->vm_start > start); > BUG_ON(vma->vm_end < end); > > - if (!thp_vma_allowable_order(vma, vma->vm_flags, TVA_FORCED_COLLAPSE, PMD_ORDER)) > + if (!collapse_allowable_orders(vma, vma->vm_flags, false)) > return -EINVAL; > > cc = kmalloc(sizeof(*cc), GFP_KERNEL);