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=-10.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,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 995E9C432BE for ; Wed, 25 Aug 2021 18:00:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 83E77610F9 for ; Wed, 25 Aug 2021 18:00:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242384AbhHYSAp (ORCPT ); Wed, 25 Aug 2021 14:00:45 -0400 Received: from mail.kernel.org ([198.145.29.99]:59132 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234684AbhHYSAo (ORCPT ); Wed, 25 Aug 2021 14:00:44 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 7F4EF60F35; Wed, 25 Aug 2021 17:59:56 +0000 (UTC) Date: Wed, 25 Aug 2021 18:59:53 +0100 From: Catalin Marinas To: Kefeng Wang Cc: will@kernel.org, ryabinin.a.a@gmail.com, andreyknvl@gmail.com, dvyukov@google.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, linux-mm@kvack.org, elver@google.com Subject: Re: [PATCH v3 1/3] vmalloc: Choose a better start address in vm_area_register_early() Message-ID: <20210825175953.GI3420@arm.com> References: <20210809093750.131091-1-wangkefeng.wang@huawei.com> <20210809093750.131091-2-wangkefeng.wang@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210809093750.131091-2-wangkefeng.wang@huawei.com> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Aug 09, 2021 at 05:37:48PM +0800, Kefeng Wang wrote: > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > index d5cd52805149..1e8fe08725b8 100644 > --- a/mm/vmalloc.c > +++ b/mm/vmalloc.c > @@ -2238,11 +2238,17 @@ void __init vm_area_add_early(struct vm_struct *vm) > */ > void __init vm_area_register_early(struct vm_struct *vm, size_t align) > { > - static size_t vm_init_off __initdata; > - unsigned long addr; > - > - addr = ALIGN(VMALLOC_START + vm_init_off, align); > - vm_init_off = PFN_ALIGN(addr + vm->size) - VMALLOC_START; > + struct vm_struct *head = vmlist, *curr, *next; > + unsigned long addr = ALIGN(VMALLOC_START, align); > + > + while (head != NULL) { Nitpick: I'd use the same pattern as in vm_area_add_early(), i.e. a 'for' loop. You might as well insert it directly than calling the add function and going through the loop again. Not a strong preference either way. > + next = head->next; > + curr = head; > + head = next; > + addr = ALIGN((unsigned long)curr->addr + curr->size, align); > + if (next && (unsigned long)next->addr - addr > vm->size) Is greater or equal sufficient? > + break; > + } > > vm->addr = (void *)addr; Another nitpick: it's very unlikely on a 64-bit architecture but not impossible on 32-bit to hit VMALLOC_END here. Maybe some BUG_ON. -- Catalin