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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 E1028C32789 for ; Thu, 8 Nov 2018 08:55:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8A65B20825 for ; Thu, 8 Nov 2018 08:55:19 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8A65B20825 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726695AbeKHS3p (ORCPT ); Thu, 8 Nov 2018 13:29:45 -0500 Received: from mga01.intel.com ([192.55.52.88]:18554 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726143AbeKHS3p (ORCPT ); Thu, 8 Nov 2018 13:29:45 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga101.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 08 Nov 2018 00:55:17 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.54,478,1534834800"; d="scan'208";a="272358525" Received: from kohsamui.iil.intel.com (HELO [10.236.193.12]) ([10.236.193.12]) by orsmga005.jf.intel.com with ESMTP; 08 Nov 2018 00:55:14 -0800 Subject: Re: [PATCH] lib/genaloc: Fix allocation of aligned buffer from non-aligned chunk To: Andrew Morton Cc: sbates@raithlin.com, logang@deltatee.com, danielmentz@google.com, mathieu.desnoyers@efficios.com, linux-kernel@vger.kernel.org, labbott@redhat.com References: <1541506853-10685-1-git-send-email-alexey.skidanov@intel.com> <20181106141542.08a9d7de30a439ec9fe50486@linux-foundation.org> <20181107141244.624161486d7b187eb02b714a@linux-foundation.org> From: Alexey Skidanov Message-ID: <8d68007d-9be4-cf1b-2c6e-ed711fd3e673@intel.com> Date: Thu, 8 Nov 2018 10:56:50 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.2.1 MIME-Version: 1.0 In-Reply-To: <20181107141244.624161486d7b187eb02b714a@linux-foundation.org> 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 11/8/18 00:12, Andrew Morton wrote: > On Wed, 7 Nov 2018 08:27:31 +0200 Alexey Skidanov wrote: > >> >> >> On 11/7/18 12:15 AM, Andrew Morton wrote: >>> On Tue, 6 Nov 2018 14:20:53 +0200 Alexey Skidanov wrote: >>> >>>> On success, gen_pool_first_fit_align() returns the bit number such that >>>> chunk_start_addr + (bit << order) is properly aligned. On failure, >>>> the bitmap size parameter is returned. >>>> >>>> When the chunk_start_addr isn't aligned properly, the >>>> chunk_start_addr + (bit << order) isn't aligned too. >>>> >>>> To fix this, gen_pool_first_fit_align() takes into account >>>> the chunk_start_addr alignment and returns the bit value such that >>>> chunk_start_addr + (bit << order) is properly aligned >>>> (exactly as it done in CMA). >>>> >>>> ... >>>> >>>> --- a/include/linux/genalloc.h >>>> +++ b/include/linux/genalloc.h >>>> >>>> ... >>>> >>>> + struct gen_pool *pool, unsigned long start_add) >>>> >>>> ... >>>> >>>> + struct gen_pool *pool, unsigned long start_add) >>>> >>>> ... >>>> >>>> + struct gen_pool *pool, unsigned long start_add) >>>> >>>> ... >>>> >>> >>> We have three typos here. Which makes me wonder why we're passing the >>> new argument and then not using it? >>> >> genpool uses allocation callbacks function that implement some >> allocation strategy - bes fit, first fit, ... All of them has the same >> type. The added chunk start_addr is used only in one of them - >> gen_pool_first_fit_align() > > OK, but the argument name here is start_add, not start_addr. > Sure, I'll fix.