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=-3.8 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 8F4D4C433E7 for ; Wed, 2 Sep 2020 15:54:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 57783208B3 for ; Wed, 2 Sep 2020 15:54:39 +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="bRuJLPF8" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728210AbgIBPyg (ORCPT ); Wed, 2 Sep 2020 11:54:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53750 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726173AbgIBPy3 (ORCPT ); Wed, 2 Sep 2020 11:54:29 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6342CC061244; Wed, 2 Sep 2020 08:54:28 -0700 (PDT) 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=zMA6zInZMPfkpW5sAnWFlHiBAJv1wx5ytIbHdHXg1sM=; b=bRuJLPF8C4Snr+zFhJCljdfY/w LOwNHY/IurlzCI+frzWr/I2YwTtyvqO1i96uiMOKh0es2J/QKpe/VShj7LMjEG5bc6XWid+C/uifD knh6Hugg+3TQHjn4bih9rzHjKbAAQrpfrbGY8F6lDFAAMZNepVCXOdkttoA9j1y57zIk5Lt7dn7/z NMC0YSGesWGFzxDnigx1NJ7vIhEAZOqKITORYB9PfimxUgTCWj+FVdmUUhimA0dwwSG2ADCJ7ANX2 U3/heI4KMqDhkltlOaFXldOjLcK7OyFgVdfXJXQzLRYyh+5jWsRw/Sqz+fdvVf4Ytpttr6/8r95b4 U3/z+XNw==; Received: from willy by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1kDV5e-0004UT-5Y; Wed, 02 Sep 2020 15:54:26 +0000 Date: Wed, 2 Sep 2020 16:54:26 +0100 From: Matthew Wilcox To: David Howells Cc: linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH 3/6] mm: Push readahead_control down into force_page_cache_readahead() [ver #2] Message-ID: <20200902155426.GY14765@casper.infradead.org> References: <159906145700.663183.3678164182141075453.stgit@warthog.procyon.org.uk> <159906147806.663183.767620073654469472.stgit@warthog.procyon.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <159906147806.663183.767620073654469472.stgit@warthog.procyon.org.uk> Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Wed, Sep 02, 2020 at 04:44:38PM +0100, David Howells wrote: > +++ b/mm/fadvise.c > @@ -104,7 +104,10 @@ int generic_fadvise(struct file *file, loff_t offset, loff_t len, int advice) > if (!nrpages) > nrpages = ~0UL; > > - force_page_cache_readahead(mapping, file, start_index, nrpages); > + { > + DEFINE_READAHEAD(rac, file, mapping, start_index); > + force_page_cache_readahead(&rac, nrpages); > + } > break; This is kind of awkward. How about this: static void force_page_cache_readahead(struct address_space *mapping, struct file *file, pgoff_t index, unsigned long nr_to_read) { DEFINE_READAHEAD(rac, file, mapping, index); force_page_cache_ra(&rac, nr_to_read); } in mm/internal.h for now (and it can migrate if it needs to be somewhere else)