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 X-Spam-Level: X-Spam-Status: No, score=-9.4 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 85723C433DF for ; Sat, 1 Aug 2020 07:59:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5A15A20725 for ; Sat, 1 Aug 2020 07:59:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728352AbgHAH7C (ORCPT ); Sat, 1 Aug 2020 03:59:02 -0400 Received: from mail-lj1-f195.google.com ([209.85.208.195]:41686 "EHLO mail-lj1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726338AbgHAH7C (ORCPT ); Sat, 1 Aug 2020 03:59:02 -0400 Received: by mail-lj1-f195.google.com with SMTP id s16so19447266ljc.8; Sat, 01 Aug 2020 00:58:59 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:from:to:cc:references:autocrypt :message-id:date:user-agent:mime-version:in-reply-to :content-language:content-transfer-encoding; bh=EFbGqOOdeXwP67nMuLpqONcvXNcyDROXgQaj7SZmhps=; b=ESStQoqU1ajH/dVcA43QAeXriKlUEm5nS+LwdNOS807W1yiuc2PHWthp+ZgLhFAU2n uJjV/9yNnTBpOthnSmQKn+QVMIJTKmivYes47XsRUqOWoKgAWowBBA1hGkwvhRJu5IzH aI/2qEnP+BnqrDcrJdzkHJy2yESa+/NuZZmIfZhUB+/y7WeMWVRaldniHIXe7oA5Vued CNJrXbBtDQ+5qjsH3mZE1k1lsbvubnbrsb/qmSyOw5XMDzBQDT5ZC9fW8vV6S0HRaAs6 wmxF8IWtTRXCZR1e7cycz62wtEAFmxHK5+nLZwOH9Y5QdSTUiiWgxMFZKAh8ODT3943+ ZhUg== X-Gm-Message-State: AOAM533h0dwaUIwpKWuarTKuHidhtp1iVWExYNYj0YiAPuYkfi1FMjW3 ISX3wKzzK1vptp4qRPNr4NbhcJXdSoc= X-Google-Smtp-Source: ABdhPJyF7h+z1lcy8CIfsddNfsQnYDmk9V6G18KIM38XE6TpPNgkKB9gjRMI9FFEKNrmfMBuwMBfVQ== X-Received: by 2002:a2e:9f4e:: with SMTP id v14mr3695470ljk.72.1596268738539; Sat, 01 Aug 2020 00:58:58 -0700 (PDT) Received: from [10.68.32.192] (broadband-37-110-38-130.ip.moscow.rt.ru. [37.110.38.130]) by smtp.gmail.com with ESMTPSA id t18sm2507673lfb.69.2020.08.01.00.58.57 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sat, 01 Aug 2020 00:58:57 -0700 (PDT) Subject: Re: [PATCH] scsi: libcxgbi: use kvzalloc instead of opencoded kzalloc/vzalloc From: Denis Efremov To: Joe Perches , "Martin K. Petersen" , "James E.J. Bottomley" Cc: linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org References: <20200731215524.14295-1-efremov@linux.com> <33d943d2b83f17371df09b5962c856ea2d894954.camel@perches.com> <70fb8220-2102-adb5-bbe6-9c2ea74a0623@linux.com> <8638183f559c0f8f8d377bd0a6c91903b2c588df.camel@perches.com> Autocrypt: addr=efremov@linux.com; keydata= mQINBFsJUXwBEADDnzbOGE/X5ZdHqpK/kNmR7AY39b/rR+2Wm/VbQHV+jpGk8ZL07iOWnVe1 ZInSp3Ze+scB4ZK+y48z0YDvKUU3L85Nb31UASB2bgWIV+8tmW4kV8a2PosqIc4wp4/Qa2A/ Ip6q+bWurxOOjyJkfzt51p6Th4FTUsuoxINKRMjHrs/0y5oEc7Wt/1qk2ljmnSocg3fMxo8+ y6IxmXt5tYvt+FfBqx/1XwXuOSd0WOku+/jscYmBPwyrLdk/pMSnnld6a2Fp1zxWIKz+4VJm QEIlCTe5SO3h5sozpXeWS916VwwCuf8oov6706yC4MlmAqsQpBdoihQEA7zgh+pk10sCvviX FYM4gIcoMkKRex/NSqmeh3VmvQunEv6P+hNMKnIlZ2eJGQpz/ezwqNtV/przO95FSMOQxvQY 11TbyNxudW4FBx6K3fzKjw5dY2PrAUGfHbpI3wtVUNxSjcE6iaJHWUA+8R6FLnTXyEObRzTS fAjfiqcta+iLPdGGkYtmW1muy/v0juldH9uLfD9OfYODsWia2Ve79RB9cHSgRv4nZcGhQmP2 wFpLqskh+qlibhAAqT3RQLRsGabiTjzUkdzO1gaNlwufwqMXjZNkLYu1KpTNUegx3MNEi2p9 CmmDxWMBSMFofgrcy8PJ0jUnn9vWmtn3gz10FgTgqC7B3UvARQARAQABtCFEZW5pcyBFZnJl bW92IDxlZnJlbW92QGxpbnV4LmNvbT6JAlcEEwEIAEECGwMFCwkIBwIGFQoJCAsCBBYCAwEC HgECF4ACGQEWIQR2VAM2ApQN8ZIP5AO1IpWwM1AwHwUCXsQtuwUJB31DPwAKCRC1IpWwM1Aw H3dQD/9E/hFd2yPwWA5cJ5jmBeQt4lBi5wUXd2+9Y0mBIn40F17Xrjebo+D8E5y6S/wqfImW nSDYaMfIIljdjmUUanR9R7Cxd/Z548Qaa4F1AtB4XN3W1L49q21h942iu0yxSLZtq9ayeja6 flCB7a+gKjHMWFDB4nRi4gEJvZN897wdJp2tAtUfErXvvxR2/ymKsIf5L0FZBnIaGpqRbfgG Slu2RSpCkvxqlLaYGeYwGODs0QR7X2i70QGeEzznN1w1MGKLOFYw6lLeO8WPi05fHzpm5pK6 mTKkpZ53YsRfWL/HY3kLZPWm1cfAxa/rKvlhom+2V8cO4UoLYOzZLNW9HCFnNxo7zHoJ1shR gYcCq8XgiJBF6jfM2RZYkOAJd6E3mVUxctosNq6av3NOdsp1Au0CYdQ6Whi13azZ81pDlJQu Hdb0ZpDzysJKhORsf0Hr0PSlYKOdHuhl8fXKYOGQxpYrWpOnjrlEORl7NHILknXDfd8mccnf 4boKIZP7FbqSLw1RSaeoCnqH4/b+ntsIGvY3oJjzbQVq7iEpIhIoQLxeklFl1xvJAOuSQwII I9S0MsOm1uoT/mwq+wCYux4wQhALxSote/EcoUxK7DIW9ra4fCCo0bzaX7XJ+dJXBWb0Ixxm yLl39M+7gnhvZyU+wkTYERp1qBe9ngjd0QTZNVi7MbkCDQRbCVF8ARAA3ITFo8OvvzQJT2cY nPR718Npm+UL6uckm0Jr0IAFdstRZ3ZLW/R9e24nfF3A8Qga3VxJdhdEOzZKBbl1nadZ9kKU nq87te0eBJu+EbcuMv6+njT4CBdwCzJnBZ7ApFpvM8CxIUyFAvaz4EZZxkfEpxaPAivR1Sa2 2x7OMWH/78laB6KsPgwxV7fir45VjQEyJZ5ac5ydG9xndFmb76upD7HhV7fnygwf/uIPOzNZ YVElGVnqTBqisFRWg9w3Bqvqb/W6prJsoh7F0/THzCzp6PwbAnXDedN388RIuHtXJ+wTsPA0 oL0H4jQ+4XuAWvghD/+RXJI5wcsAHx7QkDcbTddrhhGdGcd06qbXe2hNVgdCtaoAgpCEetW8 /a8H+lEBBD4/iD2La39sfE+dt100cKgUP9MukDvOF2fT6GimdQ8TeEd1+RjYyG9SEJpVIxj6 H3CyGjFwtIwodfediU/ygmYfKXJIDmVpVQi598apSoWYT/ltv+NXTALjyNIVvh5cLRz8YxoF sFI2VpZ5PMrr1qo+DB1AbH00b0l2W7HGetSH8gcgpc7q3kCObmDSa3aTGTkawNHzbceEJrL6 mRD6GbjU4GPD06/dTRIhQatKgE4ekv5wnxBK6v9CVKViqpn7vIxiTI9/VtTKndzdnKE6C72+ jTwSYVa1vMxJABtOSg8AEQEAAYkCPAQYAQgAJgIbDBYhBHZUAzYClA3xkg/kA7UilbAzUDAf BQJexC4MBQkHfUOQAAoJELUilbAzUDAfPYoQAJdBGd9WZIid10FCoI30QXA82SHmxWe0Xy7h r4bbZobDPc7GbTHeDIYmUF24jI15NZ/Xy9ADAL0TpEg3fNVad2eslhCwiQViWfKOGOLLMe7v zod9dwxYdGXnNRlW+YOCdFNVPMvPDr08zgzXaZ2+QJjp44HSyzxgONmHAroFcqCFUlfAqUDO T30gV5bQ8BHqvfWyEhJT+CS3JJyP8BmmSgPa0Adlp6Do+pRsOO1YNNO78SYABhMi3fEa7X37 WxL31TrNCPnIauTgZtf/KCFQJpKaakC3ffEkPhyTjEl7oOE9xccNjccZraadi+2uHV0ULA1m ycHhb817A03n1I00QwLf2wOkckdqTqRbFFI/ik69hF9hemK/BmAHpShI+z1JsYT9cSs8D7wb aF/jQVy4URensgAPkgXsRiboqOj/rTz9F5mpd/gPU/IOUPFEMoo4TInt/+dEVECHioU3RRrW EahrGMfRngbdp/mKs9aBR56ECMfFFUPyI3VJsNbgpcIJjV/0N+JdJKQpJ/4uQ2zNm0wH/RU8 CRJvEwtKemX6fp/zLI36Gvz8zJIjSBIEqCb7vdgvWarksrhmi6/Jay5zRZ03+k6YwiqgX8t7 ANwvYa1h1dQ36OiTqm1cIxRCGl4wrypOVGx3OjCar7sBLD+NkwO4RaqFvdv0xuuy4x01VnOF Message-ID: <47da22c0-d641-e94f-d38e-8af225ca115a@linux.com> Date: Sat, 1 Aug 2020 10:58:56 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 8/1/20 10:51 AM, Denis Efremov wrote: > > > On 8/1/20 1:24 AM, Joe Perches wrote: >> On Sat, 2020-08-01 at 01:10 +0300, Denis Efremov wrote: >>> >>> On 8/1/20 12:58 AM, Joe Perches wrote: >>>> On Sat, 2020-08-01 at 00:55 +0300, Denis Efremov wrote: >>>>> Remove cxgbi_alloc_big_mem(), cxgbi_free_big_mem() functions >>>>> and use kvzalloc/kvfree instead. >>>> >>>> Sensible, thanks. >>>> >>>>> diff --git a/drivers/scsi/cxgbi/libcxgbi.c b/drivers/scsi/cxgbi/libcxgbi.c >>>> [] >>>>> @@ -77,9 +77,9 @@ int cxgbi_device_portmap_create(struct cxgbi_device *cdev, unsigned int base, >>>>> { >>>>> struct cxgbi_ports_map *pmap = &cdev->pmap; >>>>> >>>>> - pmap->port_csk = cxgbi_alloc_big_mem(max_conn * >>>>> - sizeof(struct cxgbi_sock *), >>>>> - GFP_KERNEL); >>>>> + pmap->port_csk = kvzalloc(array_size(max_conn, >>>>> + sizeof(struct cxgbi_sock *)), >>>>> + GFP_KERNEL); >>>> >>>> missing __GFP_NOWARN >>>> >>> >>> kvmalloc_node adds __GFP_NOWARN internally to kmalloc call >>> https://elixir.bootlin.com/linux/v5.8-rc4/source/mm/util.c#L568 >> >> Only when there's a fallback, and the fallback does not. >> > > Sorry, Joe, I don't understand why do we need to add __GFP_NOWARN here. > > We use GFP_KERNEL for allocation. cxgbi_alloc_big_mem adds __GFP_NOWARN only to kzalloc(). > kvzalloc is: kvmalloc(size, flags | __GFP_ZERO) > kvmalloc is: kvmalloc_node(size, flags, NUMA_NO_NODE) > kvmalloc_node: > if ((flags & GFP_KERNEL) != GFP_KERNEL) // false, flags == GFP_KERNEL|__GFP_ZERO > return kmalloc_node(size, flags, node); > > if (size > PAGE_SIZE) { > kmalloc_flags |= __GFP_NOWARN; // add __GFP_NOWARN for "big" allocations > > if (!(kmalloc_flags & __GFP_RETRY_MAYFAIL)) > kmalloc_flags |= __GFP_NORETRY; > } > > // kmalloc_flags == GFP_KERNEL|__GFP_ZERO|__GFP_NOWARN if size > PAGE_SIZE > ret = kmalloc_node(size, kmalloc_flags, node); > > if (ret || size <= PAGE_SIZE) > return ret; > > // flags == GFP_KERNEL|__GFP_ZERO > return __vmalloc_node(size, 1, flags, node, > __builtin_return_address(0)); > > So, to my understanding the difference is only that cxgbi_alloc_big_mem adds __GFP_NOWARN > to kzalloc unconditionally, kvzalloc adds __GFP_NOWARN to kmalloc_node if size > PAGE_SIZE. > We use: max_conn * sizeof(struct cxgbi_sock *) in allocation. max_conn can be either > CXGBI_MAX_CONN or CXGB4I_MAX_CONN. CXGBI_MAX_CONN == 16384, CXGB4I_MAX_CONN == 16384. > Thus the allocation is bigger than PAGE_SIZE and kvmalloc_node adds __GFP_NOWARN to the > kmalloc_node call. Maybe I missed something? > Of course max_conn can be smaller than CXGBI_MAX_CONN and CXGB4I_MAX_CONN and size < PAGE_SIZE. However, it's by design not to warn on "small" allocations in kvmalloc_node and it will not even try to call __vmalloc_node if "small" allocation will fail with kmalloc_node. I think that this behavior fits the cxgbi_device_portmap_create() context call.