From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5FFE1CA0EE4 for ; Sat, 16 Aug 2025 07:50:01 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id EA9A58E023E; Sat, 16 Aug 2025 03:50:00 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id E5A568E000B; Sat, 16 Aug 2025 03:50:00 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D49138E023E; Sat, 16 Aug 2025 03:50:00 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id C301D8E000B for ; Sat, 16 Aug 2025 03:50:00 -0400 (EDT) Received: from smtpin11.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 651E358C9E for ; Sat, 16 Aug 2025 07:50:00 +0000 (UTC) X-FDA: 83781846960.11.435014D Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by imf26.hostedemail.com (Postfix) with ESMTP id ECC6514000A for ; Sat, 16 Aug 2025 07:49:57 +0000 (UTC) Authentication-Results: imf26.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b="YT5WM/+n"; spf=pass (imf26.hostedemail.com: domain of david@redhat.com designates 170.10.129.124 as permitted sender) smtp.mailfrom=david@redhat.com; dmarc=pass (policy=quarantine) header.from=redhat.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1755330598; h=from:from:sender: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:dkim-signature; bh=17PhsuAKsSKCbFAc67SwRG6K2FiDsT7yekkoNHVBnxE=; b=OBB77d0GLC/oYR+dYJ9D9JwETDdtOWYH+awoEIy6VYlWjO6pZk1zhhSYcTNmejr0ivxAhV UvJqyc6cbNK2E0LmbctSZN9DMf1KmOpAsvTiXIWUqM2Huq3BYTun8iIuRBwXe1Jlm2OryB PvB7tjOKUH9IkO+Svxaflhu0ZCViHVk= ARC-Authentication-Results: i=1; imf26.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b="YT5WM/+n"; spf=pass (imf26.hostedemail.com: domain of david@redhat.com designates 170.10.129.124 as permitted sender) smtp.mailfrom=david@redhat.com; dmarc=pass (policy=quarantine) header.from=redhat.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1755330598; a=rsa-sha256; cv=none; b=bQBMZKROv3+/lcp5zayeyNr0H4Jb+hE8j3IFIDGGaYHGId6DwUa7aK4MosX6Twe0Y/nmt6 ehLmrn30Xz8c1qOEAIj9CYoXYMKxiWsIlrCqu2wjoL/uC777DMz9RwMyxQrz+7UsBOLiz3 Nm/KLu2v1AVlCj4QRR0sJS8BaIJpeD0= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1755330597; 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:autocrypt:autocrypt; bh=17PhsuAKsSKCbFAc67SwRG6K2FiDsT7yekkoNHVBnxE=; b=YT5WM/+nakEIQeBpBCROqr6sWdEOISVSM9SyL9yxfbPyOOgyUXP9/FAs6/8GS3i8gr/lZf oze4xNsk/QSm9zY5t/MB/us8MpMcNj6Y4irKA7j+RWx5QWpPZFP+kHhw8nPt7LQf8U8G0M z6HNSdliavlPtgvSPQVCvSpg9bsEsp0= Received: from mail-wr1-f71.google.com (mail-wr1-f71.google.com [209.85.221.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-341-Zn-MHR19PE2lZ4WCvgOkVQ-1; Sat, 16 Aug 2025 03:49:55 -0400 X-MC-Unique: Zn-MHR19PE2lZ4WCvgOkVQ-1 X-Mimecast-MFC-AGG-ID: Zn-MHR19PE2lZ4WCvgOkVQ_1755330594 Received: by mail-wr1-f71.google.com with SMTP id ffacd0b85a97d-3b9d41b779aso1656608f8f.0 for ; Sat, 16 Aug 2025 00:49:55 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1755330594; x=1755935394; h=content-transfer-encoding:in-reply-to:autocrypt:content-language :from:references:cc:to:subject:user-agent:mime-version:date :message-id:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=17PhsuAKsSKCbFAc67SwRG6K2FiDsT7yekkoNHVBnxE=; b=U0mtsPbbb8xf3Xj2xk6zbeyCMpWsmweEIJQI06QkqPYLv4aw4uWOM+A+WW4S0t7IXk iOjpldUqJ4f3TCrUQUSOMUCYr1mURJYklooD9Q2+pm2JMKWy0ImPmsDPnVBEjgdmbDtA 1893euduHZGCplff1pkrdx2YX8iTd6PtggtKGb/NQnGRVkdz8EC1DAanQU4+R2xgKgPH 43NI40vgpKxvtYrOWFlNuMoXFlxmVNJdo/PPfEHpyG7PK/m3L6gPv/kpewG4Gcya+Tjy MeYiVDjodrXl4mhvDjvU3GseACwV9qSu1ZBDainQ1LHEmEvAnifAIX8K47eVk23ftqvY QVrQ== X-Forwarded-Encrypted: i=1; AJvYcCUnucsR8cFCtZ0G5MWOEzTTPEnWL+uks3EY2CgpAGsEeZSGw7Z1K2K3TbC1F7KdlIGzTKLrCEoJWg==@kvack.org X-Gm-Message-State: AOJu0Yz2VRBOFxekauySoh3YZihTrVIS/xVTBo+Zykz+/1ffYHIsb/+4 3FPXCUfq4n1PO8ne2YWrxVjOxKIWz8nO3tcBMTEtxOkUzb2wdtKjRHLUYzDgXH6mimiMc3G1uNN 3rDZT0mv1b8FE1q2PR12vDa1Gx79nd9wKr7EYIi4TlhF7LeQJz8kp X-Gm-Gg: ASbGncuqRPZWcvnKNbnwoJoifVqH5TAuLU+X1yoRSSXmOHcQaBDYZpFuHLzi/3Rufjj FrDZolYKaWtrWjVlOwRYY0B+zxWMeiEu1N0nppYxH9i+00BV6M42B3TA33+NWp75RXGXuivORAY Fe2naZxtRTxtaLdiNJyJ4Y8hGX7E0cI6mXEPLJb7e1Od9d5nT+0s+cZ87v0rL0x6t4wJIr+ylL4 dth0NRNm/FzbPLxC/W9juSepCBIzq3wyeUXDWWSFiqqZdCZloXjoYXUHFT/ciQGjzvn/kjkHeSJ d0B26Edhi1TaiklJm3j18C+q8C0tKYskxYMq0/cMAOYT+qBy+D9THhLrh/8f6r9/EBWK6bwtgMO b9/r8/4/r2MlsPUsm5AUJ9oANcjilhaphiF1ervoeqnMD8EHEjbCSPAnY02W8lW/g8A8= X-Received: by 2002:a05:600c:3b09:b0:459:dbb5:399d with SMTP id 5b1f17b1804b1-45a2183d324mr35149095e9.19.1755330594441; Sat, 16 Aug 2025 00:49:54 -0700 (PDT) X-Google-Smtp-Source: AGHT+IFBpn3b3LLsYpviEIlgcbkyUmsfqPLLDuIIrOYOdct8HP+3se8zsc6xjWIyVRDTQ5Qc6vOrKw== X-Received: by 2002:a05:600c:3b09:b0:459:dbb5:399d with SMTP id 5b1f17b1804b1-45a2183d324mr35148875e9.19.1755330593820; Sat, 16 Aug 2025 00:49:53 -0700 (PDT) Received: from ?IPV6:2003:d8:2f23:c700:d8ae:41bf:492a:9e4c? (p200300d82f23c700d8ae41bf492a9e4c.dip0.t-ipconnect.de. [2003:d8:2f23:c700:d8ae:41bf:492a:9e4c]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-45a1fe2c019sm66592525e9.17.2025.08.16.00.49.52 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sat, 16 Aug 2025 00:49:53 -0700 (PDT) Message-ID: <167acb82-1368-4c8e-89bd-8dbe4877d5bb@redhat.com> Date: Sat, 16 Aug 2025 09:49:52 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] mm/cma: print total and used pages in cma_alloc() To: Andrew Morton Cc: Xiang Gao , lorenzo.stoakes@oracle.com, Liam.Howlett@oracle.com, vbabka@suse.cz, rppt@kernel.org, surenb@google.com, mhocko@suse.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, gaoxiang17 References: <20250816042842.3959315-1-gxxa03070307@gmail.com> <20250815234528.882ab58247cefc96e4137811@linux-foundation.org> <701bfbb4-6c12-4614-a322-def3ca923c78@redhat.com> <20250816003418.b2a62f6ddbcf9468fde87a18@linux-foundation.org> From: David Hildenbrand Autocrypt: addr=david@redhat.com; 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 B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzSREYXZpZCBIaWxk ZW5icmFuZCA8ZGF2aWRAcmVkaGF0LmNvbT7CwZoEEwEIAEQCGwMCF4ACGQEFCwkIBwICIgIG FQoJCAsCBBYCAwECHgcWIQQb2cqtc1xMOkYN/MpN3hD3AP+DWgUCaJzangUJJlgIpAAKCRBN 3hD3AP+DWhAxD/9wcL0A+2rtaAmutaKTfxhTP0b4AAp1r/eLxjrbfbCCmh4pqzBhmSX/4z11 opn2KqcOsueRF1t2ENLOWzQu3Roiny2HOU7DajqB4dm1BVMaXQya5ae2ghzlJN9SIoopTWlR 0Af3hPj5E2PYvQhlcqeoehKlBo9rROJv/rjmr2x0yOM8qeTroH/ZzNlCtJ56AsE6Tvl+r7cW 3x7/Jq5WvWeudKrhFh7/yQ7eRvHCjd9bBrZTlgAfiHmX9AnCCPRPpNGNedV9Yty2Jnxhfmbv Pw37LA/jef8zlCDyUh2KCU1xVEOWqg15o1RtTyGV1nXV2O/mfuQJud5vIgzBvHhypc3p6VZJ lEf8YmT+Ol5P7SfCs5/uGdWUYQEMqOlg6w9R4Pe8d+mk8KGvfE9/zTwGg0nRgKqlQXrWRERv cuEwQbridlPAoQHrFWtwpgYMXx2TaZ3sihcIPo9uU5eBs0rf4mOERY75SK+Ekayv2ucTfjxr Kf014py2aoRJHuvy85ee/zIyLmve5hngZTTe3Wg3TInT9UTFzTPhItam6dZ1xqdTGHZYGU0O otRHcwLGt470grdiob6PfVTXoHlBvkWRadMhSuG4RORCDpq89vu5QralFNIf3EysNohoFy2A LYg2/D53xbU/aa4DDzBb5b1Rkg/udO1gZocVQWrDh6I2K3+cCs7BTQRVy5+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: <20250816003418.b2a62f6ddbcf9468fde87a18@linux-foundation.org> X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: XW2kyg5lDMUdzEV3K88-LrmvOrv-LqFNnuAFWdYkigU_1755330594 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Stat-Signature: z5fc4wy1q44u8388i79uyiowj3nuu8wf X-Rspam-User: X-Rspamd-Queue-Id: ECC6514000A X-Rspamd-Server: rspam05 X-HE-Tag: 1755330597-396355 X-HE-Meta: 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 4Acg6b94 o/lklZMNxnkG1LhZ/hNb8ZZ4AJYQavgmbD0Rwp6keAyVa6taeTEMjS+zztrlmZSzNjrAhnVARxfFmarBAIZYVqSxSE5PwkSWZPS7bxlwVRwKwJCT4tMi1x8SM3b2BPquXO2oGOOIKIJFYeFlTOem0OqfEbrtfrhIHj60mWjMETv6+B6tYpu4R3ybNRcXp1S+0eIuLcktKRnETfTsUO0BXruql02qnxKIGEEuHEXn04Ik1oFo/m5dQ+Y9P5JyFv3uNe+FtROj7qPE53rsnrDKgoIcOH1qQaLiwLYMOP6U29qJIGffHPrk0hca73qwEfFQZOTHbnX7WXAmG10xQKA4A5SEZnUN5gI/bbqPmqCVWhKPCXK8e5v1ViPas7B1qOMjf1gTjbjYF7avwdhBSdtU2/CpvQKs++EL2CWxOL1RpeiuR8kVD3gRVVQ0pKj13sj4VX43rVtEFBhWCZLni87ltykQPeQ== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 16.08.25 09:34, Andrew Morton wrote: > On Sat, 16 Aug 2025 08:56:47 +0200 David Hildenbrand wrote: > >> On 16.08.25 08:45, Andrew Morton wrote: >>> On Sat, 16 Aug 2025 08:27:39 +0200 David Hildenbrand wrote: >>> >>>>> @@ -858,8 +869,8 @@ static struct page *__cma_alloc(struct cma *cma, unsigned long count, >>>>> if (!cma || !cma->count) >>>>> return page; >>>>> >>>>> - pr_debug("%s(cma %p, name: %s, count %lu, align %d)\n", __func__, >>>>> - (void *)cma, cma->name, count, align); >>>>> + pr_debug("%s(cma %p, name: %s, total pages: %lu, used pages: %lu, request pages: %lu, align %d)\n", >>>>> + __func__, (void *)cma, cma->name, cma->count, cma_get_used_pages(cma), count, align); >>>> >>>> ^ one space missing for proper indentation. >>>> >>>> But doing another spinlock cycle just for debugging purposes? That does >>>> not feel right, sorry. >>> >>> If we're calling pr_debug() frequently enough for this to matter, we >>> have other problems! >> >> We call it for each and every actual CMA allocation? I really don't see >> why we want to just randomly make CMA allocation latency worse. > > pr_debug() is 12 million times more expensive than a spin_lock()! > >> Is the existing pr_debug() a problem? Maybe. But who actually has debug >> messages enabled in any sane setup? > > Nobody, clearly. If anyone enabled pr_debug() in here, they'd > immediately have to remove those statements to get any work done. Kill > it. I just learned that pr_debug() on a !CONFIG_DEBUG kernel translates to no_printk(), which is just a mostly-empty macro that doesn't really use any of the parameters. I would assume the cma_get_used_pages() would get completely optimized out in that case. So, I don't care, but ... moving to tracing seems much more reasonable. -- Cheers David / dhildenb