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=-3.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no 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 97B16C433E0 for ; Wed, 23 Dec 2020 15:53:02 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 0F9CD22210 for ; Wed, 23 Dec 2020 15:53:01 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0F9CD22210 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 4FB0C8D0031; Wed, 23 Dec 2020 10:53:01 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 4AC0A8D0026; Wed, 23 Dec 2020 10:53:01 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 3744A8D0031; Wed, 23 Dec 2020 10:53:01 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0168.hostedemail.com [216.40.44.168]) by kanga.kvack.org (Postfix) with ESMTP id 2145F8D0026 for ; Wed, 23 Dec 2020 10:53:01 -0500 (EST) Received: from smtpin30.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id DF591180AD822 for ; Wed, 23 Dec 2020 15:53:00 +0000 (UTC) X-FDA: 77624990520.30.sound41_1d0a53127469 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin30.hostedemail.com (Postfix) with ESMTP id B07D2180B3C85 for ; Wed, 23 Dec 2020 15:53:00 +0000 (UTC) X-HE-Tag: sound41_1d0a53127469 X-Filterd-Recvd-Size: 2682 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf25.hostedemail.com (Postfix) with ESMTP for ; Wed, 23 Dec 2020 15:52:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.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; bh=ZzbHBDfwrLQXFpf8glXNdNep4b6to1I3c9fdVvbb1Rs=; b=LlAfVZ832CeCQX4WS/8e9Xf542 fq6syhLmhblRiPAq27ncYBnNMRz0gxp4abk3jaGqVkgM4tFkZ+h0MYyPbDT2xIZyukR0yGNKU+IJz iqUL3SFNRNALIzi1a3baXE7OfCEGizF9XiczWvjVWg9z91W0hndB5/9l/drrAJZ8dF3Oe6eNsevO1 bKxQaiy93pQ9Cg1QqSbkZhFpiWU95Dol283GyrEhxyFkw8bzmjL1+GeQqrE0KJKtoKayKXSQK21uR C4jbqUgqtAlX3ud0TFj6sAn7I6ZwWI48rlMJC1CxzJtv+6RMjPVqFFdHJcwnO8rrOThH+SN7Xk824 fz9Hftbg==; Received: from hch by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1ks6Ra-0001f9-KX; Wed, 23 Dec 2020 15:52:54 +0000 Date: Wed, 23 Dec 2020 15:52:54 +0000 From: Christoph Hellwig To: Matthew Wilcox Cc: Christoph Hellwig , Andrew Morton , Souptick Joarder , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Alex Shi Subject: Re: [PATCH] mm: add prototype for __add_to_page_cache_locked() Message-ID: <20201223155254.GA6138@infradead.org> References: <1608646792-29073-1-git-send-email-jrdr.linux@gmail.com> <20201222204000.GN874@casper.infradead.org> <20201222155345.e7086ad37967c9b7feae29e4@linux-foundation.org> <20201223083126.GA27049@infradead.org> <20201223121136.GP874@casper.infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201223121136.GP874@casper.infradead.org> X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, Dec 23, 2020 at 12:11:36PM +0000, Matthew Wilcox wrote: > On Wed, Dec 23, 2020 at 08:31:26AM +0000, Christoph Hellwig wrote: > > Can we please make the eBPF code stop referencing this function instead > > of papering over this crap? It has no business poking into page cache > > internals. > > The reference from the BPF code is simply "you can inject errors here". > And I think we want to be able to inject errors to test the error paths, > no? Something that expects a symbol to be global is just pretty broken. I think it need to change so that whatever instrumentation is done can coexist with a static function.