From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f178.google.com (mail-pf0-f178.google.com [209.85.192.178]) by kanga.kvack.org (Postfix) with ESMTP id 589AC6B0005 for ; Mon, 11 Apr 2016 17:27:43 -0400 (EDT) Received: by mail-pf0-f178.google.com with SMTP id n1so131402921pfn.2 for ; Mon, 11 Apr 2016 14:27:43 -0700 (PDT) Received: from mail-pa0-x230.google.com (mail-pa0-x230.google.com. [2607:f8b0:400e:c03::230]) by mx.google.com with ESMTPS id q90si5595548pfa.198.2016.04.11.14.27.42 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 11 Apr 2016 14:27:42 -0700 (PDT) Received: by mail-pa0-x230.google.com with SMTP id ot11so45257260pab.1 for ; Mon, 11 Apr 2016 14:27:42 -0700 (PDT) Message-ID: <1460410060.6473.574.camel@edumazet-glaptop3.roam.corp.google.com> Subject: Re: [Lsf] [LSF/MM TOPIC] Generic page-pool recycle facility? From: Eric Dumazet Date: Mon, 11 Apr 2016 14:27:40 -0700 In-Reply-To: <20160411222309.499a2125@redhat.com> References: <1460034425.20949.7.camel@HansenPartnership.com> <20160407161715.52635cac@redhat.com> <1460042309.6473.414.camel@edumazet-glaptop3.roam.corp.google.com> <20160409111132.781a11b6@redhat.com> <1460205278.6473.486.camel@edumazet-glaptop3.roam.corp.google.com> <20160411222309.499a2125@redhat.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Jesper Dangaard Brouer Cc: lsf@lists.linux-foundation.org, Tom Herbert , Brenden Blanco , James Bottomley , linux-mm , "netdev@vger.kernel.org" , lsf-pc@lists.linux-foundation.org, Alexei Starovoitov On Mon, 2016-04-11 at 22:23 +0200, Jesper Dangaard Brouer wrote: > If we have a page-pool recycle facility, then we could use the trick, > right? (As we know that get_page_unless_zero() cannot happen for pages > in the pool). Well, if you disable everything that possibly use get_page_unless_zero(), I guess this could work. But then, you'll have to spy lkml traffic forever to make sure no new feature is added in the kernel, using this get_page_unless_zero() in a new clever way. You could use a page flag so that z BUG() triggers if get_page_unless_zero() is attempted on one of your precious pages ;)\ We had very subtle issues before my fixes (check 35b7a1915aa33da812074744647db0d9262a555c and children), so I would not waste time on the lock prefix avoidance at this point. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org