From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 C200439D6C9; Wed, 3 Jun 2026 10:00:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780480858; cv=none; b=KHss4t4WRxfWaa425ksJYIlFoDrUl08/R39iSjeVgKuC/iyB8aeZozVYcxtIKyuud004u2wCgjJIKgHJ6nz/MRFxuozDqtoxcpLHfZ1svXcKXOwqvq9ohMc4SkgMZwqtWBPJ4DPMa4HQFXeRerOhQCiXTEEF5SWCqqReijgo1D0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780480858; c=relaxed/simple; bh=+8LUElc0D1Oo7as6xnx6UefeGOKvOxID+7+71IxAR+s=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=CgEwtfDSrFo3v2e3TnFlkQvSgKC8j7lj+1Wb9XzsnIAatvltLNvcX22jIDu8jMCR7Akvvxuu+ZMSUkwcarl52zA/ZppDgrGzOTgI4NdvkzBxXRKLqFlL2z7pvtxsSWaERY8dS+E8SSqK71NcOuEg3sK78WTNlUK8QbHv4CDik+0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ML4vg+Og; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ML4vg+Og" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D4E421F00893; Wed, 3 Jun 2026 10:00:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1780480855; bh=hRdMcuu42g8NujGeqFbFyl8BzMHa5wjh/TcLvEawNqo=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=ML4vg+Og81CMlnLPvxVs5MrQVqYveAx2EOfh/vz8+WH982gQ4cOdmExulhZkEyb67 6sYPKIdUJXww6AoSUjAUgQd/9avs6hnBswbwhx/7EzRLDIvAM+lHf08TjVoCiV3oWK yyQSxT4rvZtEjS+XxRxCeEkyCHZ6S63bVV+pkXEWa7NH0F4SKWDhp3I9ni1RRt1r4m BVIw1ytGmJ5EmW5Yk+6DvmTGpobmnvrK3208l74upJzInwN1UYlrdzL5davJqxGkff IxrNmd7mlABoVWjVz/0q4tzReon4fotvSoaJiG0O4zizGDgUktuYyUPmKwbwUNK6cE k8ciaPyNs/YfQ== Message-ID: Date: Wed, 3 Jun 2026 12:00:38 +0200 Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH mm-unstable v18 11/14] mm/khugepaged: Introduce mTHP collapse support To: Nico Pache Cc: linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org, aarcange@redhat.com, akpm@linux-foundation.org, anshuman.khandual@arm.com, apopple@nvidia.com, baohua@kernel.org, baolin.wang@linux.alibaba.com, byungchul@sk.com, catalin.marinas@arm.com, cl@gentwo.org, corbet@lwn.net, dave.hansen@linux.intel.com, dev.jain@arm.com, gourry@gourry.net, hannes@cmpxchg.org, hughd@google.com, jack@suse.cz, jackmanb@google.com, jannh@google.com, jglisse@google.com, joshua.hahnjy@gmail.com, kas@kernel.org, lance.yang@linux.dev, liam@infradead.org, ljs@kernel.org, mathieu.desnoyers@efficios.com, matthew.brost@intel.com, mhiramat@kernel.org, mhocko@suse.com, peterx@redhat.com, pfalcato@suse.de, rakie.kim@sk.com, raquini@redhat.com, rdunlap@infradead.org, richard.weiyang@gmail.com, rientjes@google.com, rostedt@goodmis.org, rppt@kernel.org, ryan.roberts@arm.com, shivankg@amd.com, sunnanyong@huawei.com, surenb@google.com, thomas.hellstrom@linux.intel.com, tiwai@suse.de, vbabka@suse.cz, vishal.moola@gmail.com, wangkefeng.wang@huawei.com, will@kernel.org, willy@infradead.org, yang@os.amperecomputing.com, ying.huang@linux.alibaba.com, ziy@nvidia.com, zokeefe@google.com, Usama Arif , usamaarif642@gmail.com References: <20260522150009.121603-1-npache@redhat.com> <20260522150009.121603-12-npache@redhat.com> <19639b08-5bf1-4974-9635-c458d512fa38@redhat.com> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit > next_order: > - if ((BIT(order) - 1) & enabled_orders) { > - const u8 next_order = order - 1; > - const u16 mid_offset = offset + (nr_ptes / 2); > - > - collapse_mthp_stack_push(cc, &stack_size, mid_offset, > - next_order); > - collapse_mthp_stack_push(cc, &stack_size, offset, > - next_order); > + if (order > KHUGEPAGED_MIN_MTHP_ORDER && > + (BIT(order) - 1) & enabled_orders) { Why not a test_bit() ? But, wouldn't you want to skip orders that are not enabled and try with the next smaller one in any case before you advance the offset? -- Cheers, David