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=-7.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 61C1AC433E0 for ; Fri, 5 Feb 2021 21:15:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1552F64E51 for ; Fri, 5 Feb 2021 21:15:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231455AbhBEVOw (ORCPT ); Fri, 5 Feb 2021 16:14:52 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52710 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233189AbhBEVOd (ORCPT ); Fri, 5 Feb 2021 16:14:33 -0500 Received: from fieldses.org (fieldses.org [IPv6:2600:3c00:e000:2f7::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B7DC2C06174A for ; Fri, 5 Feb 2021 13:13:52 -0800 (PST) Received: by fieldses.org (Postfix, from userid 2815) id 0AA4C14D4; Fri, 5 Feb 2021 16:13:51 -0500 (EST) DKIM-Filter: OpenDKIM Filter v2.11.0 fieldses.org 0AA4C14D4 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fieldses.org; s=default; t=1612559631; bh=XGZLOAkvciIpfu/nSYSfEQWp+WXnvr/pic1GWFUyw/E=; h=Date:To:Cc:Subject:References:In-Reply-To:From:From; b=XcDiY3an1jSVg6HGO4ory7L2v45XAh7c0V6s49RJqds9iuaSldlWf0vZspxyaksAJ uvnnEHR5R2s75h7yTHOckMBr9dp9cC78IrZ01+cMZ1S82/VPIDSWQ9T1anuj5D5aRp GjB4FaixczOEHKIG0Uq6v3IEfBXLwgtMReIAKnzA= Date: Fri, 5 Feb 2021 16:13:51 -0500 To: Chuck Lever Cc: Neil Brown , Linux NFS Mailing List Subject: Re: releasing result pages in svc_xprt_release() Message-ID: <20210205211351.GC32030@fieldses.org> References: <811BE98B-F196-4EC1-899F-6B62F313640C@oracle.com> <87im7ffjp0.fsf@notabene.neil.brown.name> <597824E7-3942-4F11-958F-A6E247330A9E@oracle.com> <878s88fz6s.fsf@notabene.neil.brown.name> <700333BB-0928-4772-ADFB-77D92CCE169C@oracle.com> <87wnvre5cy.fsf@notabene.neil.brown.name> <9FC8FB98-2DD7-4B78-BD72-918F91FA11D9@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <9FC8FB98-2DD7-4B78-BD72-918F91FA11D9@oracle.com> User-Agent: Mutt/1.5.21 (2010-09-15) From: bfields@fieldses.org (J. Bruce Fields) Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org On Fri, Feb 05, 2021 at 08:20:28PM +0000, Chuck Lever wrote: > Baby steps. > > Because I'm perverse I started with bulk page freeing. In the course > of trying to invent a new API, I discovered there already is a batch > free_page() function called release_pages(). > > It seems to work as advertised for pages that are truly no longer > in use (ie RPC/RDMA pages) but not for pages that are still in flight > but released (ie TCP pages). > > release_pages() chains the pages in the passed-in array onto a list > by their page->lru fields. This seems to be a problem if a page > is still in use. I thought I remembered reading an lwn article about bulk page allocation. Looking around now all I can see is https://lwn.net/Articles/684616/ https://lwn.net/Articles/711075/ and I can't tell if any of that work was ever finished. --b.