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 76CB7C0044C for ; Wed, 7 Nov 2018 22:14:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4379420882 for ; Wed, 7 Nov 2018 22:14:32 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4379420882 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org 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 S1727951AbeKHHqx (ORCPT ); Thu, 8 Nov 2018 02:46:53 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:46022 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727127AbeKHHqx (ORCPT ); Thu, 8 Nov 2018 02:46:53 -0500 Received: from akpm3.svl.corp.google.com (unknown [104.133.8.65]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id 77AD9B37; Wed, 7 Nov 2018 22:14:29 +0000 (UTC) Date: Wed, 7 Nov 2018 14:14:28 -0800 From: Andrew Morton To: Alexey Skidanov Cc: sbates@raithlin.com, logang@deltatee.com, danielmentz@google.com, mathieu.desnoyers@efficios.com, linux-kernel@vger.kernel.org, labbott@redhat.com Subject: Re: [PATCH] lib/genaloc: Fix allocation of aligned buffer from non-aligned chunk Message-Id: <20181107141428.bd1f8b1a989449633394d8c1@linux-foundation.org> In-Reply-To: References: <1541506853-10685-1-git-send-email-alexey.skidanov@intel.com> <20181106141131.76e94f6b1ff2859d96792aca@linux-foundation.org> X-Mailer: Sylpheed 3.6.0 (GTK+ 2.24.31; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 7 Nov 2018 08:21:07 +0200 Alexey Skidanov wrote: > > Why does this need "fixing"? Are there current callers which can > > misalign chunk_start_addr? Or is there a requirement that future > > callers can misalign chunk_start_addr? > > > I work on adding aligned allocation support for ION heaps > (https://www.spinics.net/lists/linux-driver-devel/msg118754.html). Two > of these heaps use genpool internally. > > If you want to have an ability to allocate buffers aligned on different > boundaries (for example, 4K, 1MB, ...), this fix actually removes the > requirement for chunk_start_addr to be aligned on the max possible > alignment. OK. This sort of information should be in the changelog, please. In much detail.