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=-2.1 required=3.0 tests=DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,T_DKIM_INVALID, USER_AGENT_MUTT 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 A9204ECE560 for ; Sat, 22 Sep 2018 14:22:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 484BE2146E for ; Sat, 22 Sep 2018 14:22:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="ZzMbauLB" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 484BE2146E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.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 S1728822AbeIVUQe (ORCPT ); Sat, 22 Sep 2018 16:16:34 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:33350 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728476AbeIVUQe (ORCPT ); Sat, 22 Sep 2018 16:16:34 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=DHPyk/4n2wsdQMMLyVKEE2E4KR8yao6/DW/SfCOvR78=; b=ZzMbauLBIe+XWR004by4cNrGh BcrjrNUDn2WKUiTQJdbfiskroTGzFk3Wqt++f4GSS/0uQ24fF50Vt+GsSCbBAcq1t3mU0jPisawJd Umsn96cXnjAYm7WeXuC8Vw8VbqOXZuNXv1leTLBheNxteFUqkKnHwsb8fdH/Rj+tBLzASOdniuxzV Gh5a7S7Y73B0IkIm2sZhdjUOnjaqZATjtTWKKDhT/eNeg3XTQbXkkWB2aDsb4iR6yp7FJtNF90L0w bsrl3Z8ihqHkRqeQXdpkuEYdeGPfBfiL4UJwL+NesvYQyIKZFt5gF9+cyQhV1qt2uGKgP9JxzkOpE hoaGbRa6Q==; Received: from willy by bombadil.infradead.org with local (Exim 4.90_1 #2 (Red Hat Linux)) id 1g3iny-0004FE-6S; Sat, 22 Sep 2018 14:22:42 +0000 Date: Sat, 22 Sep 2018 07:22:41 -0700 From: Matthew Wilcox To: Souptick Joarder Cc: akpm@linux-foundation.org, mark.rutland@arm.com, aryabinin@virtuozzo.com, dvyukov@google.com, tglx@linutronix.de, gregkh@linuxfoundation.org, tchibo@google.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH] kernel/kcov: Replace vm_insert_page with vmf_insert_page Message-ID: <20180922142241.GD14042@bombadil.infradead.org> References: <20180920191254.GA22764@jordon-HP-15-Notebook-PC> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180920191254.GA22764@jordon-HP-15-Notebook-PC> User-Agent: Mutt/1.9.2 (2017-12-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Sep 21, 2018 at 12:42:54AM +0530, Souptick Joarder wrote: > for (off = 0; off < size; off += PAGE_SIZE) { > page = vmalloc_to_page(kcov->area + off); > - if (vm_insert_page(vma, vma->vm_start + off, page)) > - WARN_ONCE(1, "vm_insert_page() failed"); > + if (vmf_insert_page(vma, vma->vm_start + off, page) > + != VM_FAULT_NOPAGE) > + WARN_ONCE(1, "vmf_insert_page() failed"); > } I think this is the wrong approach (as well as being buggy). We should have a vmalloc_insert_range() _or something similar_ that replaces this entire loop. That makes each _user_ simpler. What you're trying to do right now makes each user more complex, and that's the wrong approach.