From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 7F191325726 for ; Thu, 2 Apr 2026 08:24:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775118253; cv=none; b=lajPj+tgtkcyK4/0ug8o0dWx6WUL5/cdX/fahMyUJA5Lictf1sUUgu9Fx67qHzedcDhJ+V8lr67RwoTDMTD36Asq38su6Rq0fqpLk19D4V8Jq2m1yfAM3gs+Axm0omax8R+hza4PCYlZZmlEmKanhXFm5USPGRkTLY09iFBCDKM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775118253; c=relaxed/simple; bh=jA06gc5Pe4IVkLtx5H9gdixrMkeAfECyoYC1fHc//zc=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=agqrI6p8/V0lVIdyHixtA4WPqD7Yz3ssHWeA+jTMB1h07hImRFb3i7FSymh+QwoxQNA3PER1fSwGie+eyDayW22Jbi47vpKSdVamTiWg7zJP1gT9p1qJQv1zDL+PIectZON2QRIccADwKNEdS5wOTcZVdyL828NL5s7uTSeLmG4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=jmhBxman; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="jmhBxman" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AD7F0C116C6; Thu, 2 Apr 2026 08:24:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1775118253; bh=jA06gc5Pe4IVkLtx5H9gdixrMkeAfECyoYC1fHc//zc=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=jmhBxmanWyjZ1Wdt4K2SJ1STrNnEm6Izu97jH+1vmNyGxmieonjfDmBr7jnOoKerf pwkHp9SgetcYJti68BD+aTcNPmX54eNkuRRWzzesZbjkBpySTA7TR2g6M8i5UcszOv CJ0gBkHXn8J+f7jyl88XtEW9BejRvQBE48ev7Z5OdMndlU1MB++oYxK7ELFDlCFA6T NeBCKxIrJh6mWhBW/v9wlq7Og9obDAxq8xK/ZNOS4NZnSfZZBFwnXOi3ww1QVbFOQa xnM2DPM2UtqtfwqGnsJuXwcAuKBhZdWcfnZjjzbIi6Oyc1KhNW++F4rAoDsxESMSTW zTyLUSwi2wWMw== Message-ID: <03686997-f3d2-4e6a-b4a8-99543a9f8a27@kernel.org> Date: Thu, 2 Apr 2026 10:24:06 +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 2/2] mm: huge_memory: refactor defrag_show() to use defrag_flags[] To: Breno Leitao , Andrew Morton , Lorenzo Stoakes , Zi Yan , Baolin Wang , "Liam R. Howlett" , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-team@meta.com References: <20260320-thp_defrag-v1-0-6ab15d0d26eb@debian.org> <20260320-thp_defrag-v1-2-6ab15d0d26eb@debian.org> 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: <20260320-thp_defrag-v1-2-6ab15d0d26eb@debian.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 3/20/26 17:05, Breno Leitao wrote: > Replace the hardcoded if/else chain of test_bit() calls and string > literals in defrag_show() with a loop over defrag_flags[] and > defrag_mode_strings[] arrays introduced in the previous commit. > > This makes defrag_show() consistent with defrag_store() and eliminates > the duplicated mode name strings. > > Signed-off-by: Breno Leitao > --- > mm/huge_memory.c | 38 ++++++++++++++++++++++---------------- > 1 file changed, 22 insertions(+), 16 deletions(-) > > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > index 4843e2154038f..eaa6623fa49e2 100644 > --- a/mm/huge_memory.c > +++ b/mm/huge_memory.c > @@ -447,24 +447,30 @@ static const enum transparent_hugepage_flag defrag_flags[] = { > static ssize_t defrag_show(struct kobject *kobj, > struct kobj_attribute *attr, char *buf) > { > - const char *output; > + int active = DEFRAG_NEVER; > + int len = 0; > + int i; > > - if (test_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, > - &transparent_hugepage_flags)) > - output = "[always] defer defer+madvise madvise never"; > - else if (test_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, > - &transparent_hugepage_flags)) > - output = "always [defer] defer+madvise madvise never"; > - else if (test_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, > - &transparent_hugepage_flags)) > - output = "always defer [defer+madvise] madvise never"; > - else if (test_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, > - &transparent_hugepage_flags)) > - output = "always defer defer+madvise [madvise] never"; > - else > - output = "always defer defer+madvise madvise [never]"; > + for (i = 0; i < ARRAY_SIZE(defrag_flags); i++) { > + if (test_bit(defrag_flags[i], &transparent_hugepage_flags)) { > + active = i; > + break; > + } > + } > > - return sysfs_emit(buf, "%s\n", output); > + for (i = 0; i < ARRAY_SIZE(defrag_mode_strings); i++) { > + if (i == active) > + len += sysfs_emit_at(buf, len, "[%s] ", > + defrag_mode_strings[i]); > + else > + len += sysfs_emit_at(buf, len, "%s ", > + defrag_mode_strings[i]); > + } > + > + /* Replace trailing space with newline */ > + buf[len - 1] = '\n'; > + > + return len; The old code was certainly way easier to get. But this one here looks good to me. Acked-by: David Hildenbrand (Arm) -- Cheers, David