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 D35D4443A9D for ; Thu, 13 Aug 2026 09:57:40 +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=1786615062; cv=none; b=BqO1D47dHSqJhY7jjzNYyEEGGXEs2mYASzzAecUPS4APcn+M7wNVRaO5aRt+AE59bEe40sUm/JPoZJZDJ6MJyphFXXbP/XTf1Opuz5AWSahNLR9nO4moENLStWWU1uVoHWmtJFjmoYWiFtOnQtxEN56E6GHtHE86eaae9yXigI4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786615062; c=relaxed/simple; bh=eNPpBTxYivnfrviy/EV+pDf0YcVnvsby9j06cuqCB+0=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=RbCorPQ+JPIaJnFlWjRYMXmB+DSRZ3kiBblb59QgVwjj+dS7IIjqKRAcMHLuZGtP1Kk73niXFUDvGdDoxgWzlsZjPuhlKf+mfZVNXd8Ny2WxlKAMZ/w0dGjqR+L4fn57jSUrR3KjaP2FXSEW5tw838cw74xm85eXL+vX/l4NnUc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=U4qMIT3A; 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="U4qMIT3A" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D9D721F000E9; Thu, 13 Aug 2026 09:57:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1786615060; bh=uOm/HVQGc0+vyDqcjuSjHJXpyPlAxFtMu2bcfagRXwc=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=U4qMIT3A6rZHjtcyXEEybCh8POXH7dLazzJarsH0hV4h1vlj2vQbELL0fPk55R9lV Rd2v4LECeKnv2Pezfcuo+PLr3J7u8vKEANQ7s/aIfChapu9P38haIjF9oufWLB+ZRS fzgtjGpDR7GQb+8YSs5Wg9s9awF/mdtmMKmVlHMfWbbv3ggR+9wFnQWcVFF1xuVO6n GNNcEL0LNlpFVJCVWF1Oa6AhIjCXqE42XIkMK1FUkpNivMLI7ZjjpOOQx3QcMLNXQH m6tHrgGTmCXch4SBhK1oTlHhT1XsWPZZcdZobnB0i6U37pgaG1TBvz22DRMGI89YYN 09eDLQs37hleQ== Message-ID: Date: Thu, 13 Aug 2026 11:57:30 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 1/7] mm: factor out generic PTE batch detection from swap_pte_batch() To: Shivank Garg , Andrew Morton , Lorenzo Stoakes , Rik van Riel , "Liam R. Howlett" , Vlastimil Babka , Harry Yoo , Jann Horn , Lance Yang , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Zi Yan , Matthew Brost , Joshua Hahn , Rakie Kim , Byungchul Park , Gregory Price , Ying Huang , Alistair Popple Cc: Karim Manaouil , Frank van der Linden , Kinsey Ho , Wei Xu , Bharata B Rao , David Rientjes , Dev Jain , linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20260813-migrate-rmap-batch-v2-0-3c5424c555c7@amd.com> <20260813-migrate-rmap-batch-v2-1-3c5424c555c7@amd.com> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; keydata= xsFNBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzS5EYXZpZCBIaWxk ZW5icmFuZCAoQ3VycmVudCkgPGRhdmlkQGtlcm5lbC5vcmc+wsGQBBMBCAA6AhsDBQkmWAik AgsJBBUKCQgCFgICHgUCF4AWIQQb2cqtc1xMOkYN/MpN3hD3AP+DWgUCaYJt/AIZAQAKCRBN 3hD3AP+DWriiD/9BLGEKG+N8L2AXhikJg6YmXom9ytRwPqDgpHpVg2xdhopoWdMRXjzOrIKD g4LSnFaKneQD0hZhoArEeamG5tyo32xoRsPwkbpIzL0OKSZ8G6mVbFGpjmyDLQCAxteXCLXz ZI0VbsuJKelYnKcXWOIndOrNRvE5eoOfTt2XfBnAapxMYY2IsV+qaUXlO63GgfIOg8RBaj7x 3NxkI3rV0SHhI4GU9K6jCvGghxeS1QX6L/XI9mfAYaIwGy5B68kF26piAVYv/QZDEVIpo3t7 /fjSpxKT8plJH6rhhR0epy8dWRHk3qT5tk2P85twasdloWtkMZ7FsCJRKWscm1BLpsDn6EQ4 jeMHECiY9kGKKi8dQpv3FRyo2QApZ49NNDbwcR0ZndK0XFo15iH708H5Qja/8TuXCwnPWAcJ DQoNIDFyaxe26Rx3ZwUkRALa3iPcVjE0//TrQ4KnFf+lMBSrS33xDDBfevW9+Dk6IISmDH1R HFq2jpkN+FX/PE8eVhV68B2DsAPZ5rUwyCKUXPTJ/irrCCmAAb5Jpv11S7hUSpqtM/6oVESC 3z/7CzrVtRODzLtNgV4r5EI+wAv/3PgJLlMwgJM90Fb3CB2IgbxhjvmB1WNdvXACVydx55V7 LPPKodSTF29rlnQAf9HLgCphuuSrrPn5VQDaYZl4N/7zc2wcWM7BTQRVy5+RARAA59fefSDR 9nMGCb9LbMX+TFAoIQo/wgP5XPyzLYakO+94GrgfZjfhdaxPXMsl2+o8jhp/hlIzG56taNdt VZtPp3ih1AgbR8rHgXw1xwOpuAd5lE1qNd54ndHuADO9a9A0vPimIes78Hi1/yy+ZEEvRkHk /kDa6F3AtTc1m4rbbOk2fiKzzsE9YXweFjQvl9p+AMw6qd/iC4lUk9g0+FQXNdRs+o4o6Qvy iOQJfGQ4UcBuOy1IrkJrd8qq5jet1fcM2j4QvsW8CLDWZS1L7kZ5gT5EycMKxUWb8LuRjxzZ 3QY1aQH2kkzn6acigU3HLtgFyV1gBNV44ehjgvJpRY2cC8VhanTx0dZ9mj1YKIky5N+C0f21 zvntBqcxV0+3p8MrxRRcgEtDZNav+xAoT3G0W4SahAaUTWXpsZoOecwtxi74CyneQNPTDjNg azHmvpdBVEfj7k3p4dmJp5i0U66Onmf6mMFpArvBRSMOKU9DlAzMi4IvhiNWjKVaIE2Se9BY FdKVAJaZq85P2y20ZBd08ILnKcj7XKZkLU5FkoA0udEBvQ0f9QLNyyy3DZMCQWcwRuj1m73D sq8DEFBdZ5eEkj1dCyx+t/ga6x2rHyc8Sl86oK1tvAkwBNsfKou3v+jP/l14a7DGBvrmlYjO 59o3t6inu6H7pt7OL6u6BQj7DoMAEQEAAcLBfAQYAQgAJgIbDBYhBBvZyq1zXEw6Rg38yk3e EPcA/4NaBQJonNqrBQkmWAihAAoJEE3eEPcA/4NaKtMQALAJ8PzprBEXbXcEXwDKQu+P/vts IfUb1UNMfMV76BicGa5NCZnJNQASDP/+bFg6O3gx5NbhHHPeaWz/VxlOmYHokHodOvtL0WCC 8A5PEP8tOk6029Z+J+xUcMrJClNVFpzVvOpb1lCbhjwAV465Hy+NUSbbUiRxdzNQtLtgZzOV Zw7jxUCs4UUZLQTCuBpFgb15bBxYZ/BL9MbzxPxvfUQIPbnzQMcqtpUs21CMK2PdfCh5c4gS sDci6D5/ZIBw94UQWmGpM/O1ilGXde2ZzzGYl64glmccD8e87OnEgKnH3FbnJnT4iJchtSvx yJNi1+t0+qDti4m88+/9IuPqCKb6Stl+s2dnLtJNrjXBGJtsQG/sRpqsJz5x1/2nPJSRMsx9 5YfqbdrJSOFXDzZ8/r82HgQEtUvlSXNaXCa95ez0UkOG7+bDm2b3s0XahBQeLVCH0mw3RAQg r7xDAYKIrAwfHHmMTnBQDPJwVqxJjVNr7yBic4yfzVWGCGNE4DnOW0vcIeoyhy9vnIa3w1uZ 3iyY2Nsd7JxfKu1PRhCGwXzRw5TlfEsoRI7V9A8isUCoqE2Dzh3FvYHVeX4Us+bRL/oqareJ CIFqgYMyvHj7Q06kTKmauOe4Nf0l0qEkIuIzfoLJ3qr5UyXc2hLtWyT9Ir+lYlX9efqh7mOY qIws/H2t In-Reply-To: <20260813-migrate-rmap-batch-v2-1-3c5424c555c7@amd.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 8/13/26 06:23, Shivank Garg wrote: > Factor out the generic PTE batch detection logic from swap_pte_batch() > into softleaf_pte_batch() helper, so that it can be reused by upcoming > patch that adds restore-side batching of migration entries. > > swap_pte_batch() now keeps only its swap-specific concerns and > delegates the batch detection to softleaf_pte_batch(). > > No functional changes intended. > > Signed-off-by: Shivank Garg > --- > mm/internal.h | 36 +++++++++++++++++++++--------------- > 1 file changed, 21 insertions(+), 15 deletions(-) > > diff --git a/mm/internal.h b/mm/internal.h > index a5d0488a54dc..1e1ab53b642e 100644 > --- a/mm/internal.h > +++ b/mm/internal.h > @@ -560,6 +560,26 @@ static inline void set_softleaf_ptes(struct mm_struct *mm, unsigned long addr, > } > } > > +static inline int softleaf_pte_batch(pte_t *start_ptep, int max_nr, pte_t pte) > +{ > + pte_t expected_pte = pte_next_softleaf_offset(pte); > + const pte_t *end_ptep = start_ptep + max_nr; > + pte_t *ptep = start_ptep + 1; > + Wouldn't we want some way to make sure that the softleaf entries actually carry offsets or pfns of sorts? > + VM_WARN_ON(max_nr < 1); > + > + while (ptep < end_ptep) { > + pte = ptep_get(ptep); > + > + if (!pte_same(pte, expected_pte)) > + break; > + expected_pte = pte_next_softleaf_offset(expected_pte); > + ptep++; > + } > + > + return ptep - start_ptep; > +} > + > /** > * swap_pte_batch - detect a PTE batch for a set of contiguous swap entries > * @start_ptep: Page table pointer for the first entry. > @@ -577,23 +597,9 @@ static inline void set_softleaf_ptes(struct mm_struct *mm, unsigned long addr, > */ > static inline int swap_pte_batch(pte_t *start_ptep, int max_nr, pte_t pte) > { > - pte_t expected_pte = pte_next_softleaf_offset(pte); > - const pte_t *end_ptep = start_ptep + max_nr; > - pte_t *ptep = start_ptep + 1; > - > - VM_WARN_ON(max_nr < 1); > VM_WARN_ON(!softleaf_is_swap(softleaf_from_pte(pte))); Any reason we cannot simply rename this thing and drop the VM_WARN_ON? I mean, a caller can just do that. -- Cheers, David