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=-8.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY, USER_AGENT_SANE_1 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 3A913C10F27 for ; Tue, 10 Mar 2020 10:46:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0F5AB21D7E for ; Tue, 10 Mar 2020 10:46:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="UcdMYQAO" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726331AbgCJKqT (ORCPT ); Tue, 10 Mar 2020 06:46:19 -0400 Received: from aserp2120.oracle.com ([141.146.126.78]:56310 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725937AbgCJKqS (ORCPT ); Tue, 10 Mar 2020 06:46:18 -0400 Received: from pps.filterd (aserp2120.oracle.com [127.0.0.1]) by aserp2120.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 02AAcoWR081573; Tue, 10 Mar 2020 10:46:10 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=date : from : to : cc : subject : message-id : references : mime-version : content-type : in-reply-to; s=corp-2020-01-29; bh=1RisN3S7KM3q/8X60PBMjhXZIbFkHsb770PygEikLQM=; b=UcdMYQAOyUZiSFKHzyk6WZHOZfZ1jSJpCZgDUTkHTIamr9/HJdnodla4sGz/3TYPExfx faKxU3h/FFJmqGEpHlcpUSRWQgvw65E9LLe4YbutcmO242GFBednrEi9NP84ysSOwL5a oK++BuqCkNrNbKVSSnieI427QoDr5+8PY4wD6W0Fzjzsb4DlDan9MLKKdSY6gUWT/JK4 D3dmWGD5VxLFW5btxzgSau3LqJD3zTw7G8jBcTSP4+JJt80DGUPFTPVfTibpxnCT6BnL B2pPLaFVSJpofP+dBatFF/utz8UfGK/AGyS3w7PyddyhQ3NEC/3Y0gF5LAVSTlUIi6YR Zw== Received: from aserp3020.oracle.com (aserp3020.oracle.com [141.146.126.70]) by aserp2120.oracle.com with ESMTP id 2ym3jqmsva-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 10 Mar 2020 10:46:10 +0000 Received: from pps.filterd (aserp3020.oracle.com [127.0.0.1]) by aserp3020.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 02AAcQYm069503; Tue, 10 Mar 2020 10:46:10 GMT Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by aserp3020.oracle.com with ESMTP id 2yp8nry2uf-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 10 Mar 2020 10:46:09 +0000 Received: from abhmp0016.oracle.com (abhmp0016.oracle.com [141.146.116.22]) by aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id 02AAk8Rs026312; Tue, 10 Mar 2020 10:46:08 GMT Received: from kadam (/41.57.98.10) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Tue, 10 Mar 2020 03:46:08 -0700 Date: Tue, 10 Mar 2020 13:46:01 +0300 From: Dan Carpenter To: "Joel Fernandes (Google)" Cc: linux-kernel@vger.kernel.org, devel@driverdev.osuosl.org, Todd Kjos , Greg Kroah-Hartman , Arve =?iso-8859-1?B?SGr4bm5lduVn?= , Martijn Coenen , surenb@google.com, Christian Brauner Subject: Re: [RFC] ashmem: Fix ashmem shrinker nr_to_scan Message-ID: <20200310104601.GB11561@kadam> References: <20200306011930.99378-1-joel@joelfernandes.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200306011930.99378-1-joel@joelfernandes.org> User-Agent: Mutt/1.9.4 (2018-02-28) X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9555 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 bulkscore=0 mlxscore=0 phishscore=0 spamscore=0 malwarescore=0 adultscore=0 suspectscore=0 mlxlogscore=999 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2001150001 definitions=main-2003100071 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9555 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 malwarescore=0 clxscore=1011 priorityscore=1501 mlxscore=0 phishscore=0 mlxlogscore=999 impostorscore=0 bulkscore=0 spamscore=0 suspectscore=0 lowpriorityscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2001150001 definitions=main-2003100071 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 05, 2020 at 08:19:30PM -0500, Joel Fernandes (Google) wrote: > nr_to_scan is the number of pages to be freed however ashmem doesn't > discount nr_to_scan correctly as it frees ranges. It should be > discounting them by pages than by ranges. Correct the issue. > > Cc: surenb@google.com > Signed-off-by: Joel Fernandes (Google) > --- > drivers/staging/android/ashmem.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/drivers/staging/android/ashmem.c b/drivers/staging/android/ashmem.c > index 5891d0744a760..cb525ea6db98a 100644 > --- a/drivers/staging/android/ashmem.c > +++ b/drivers/staging/android/ashmem.c > @@ -458,6 +458,8 @@ ashmem_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) > lru_del(range); > > freed += range_size(range); > + sc->nr_to_scan -= range_size(range); ^^ Two space characters. In the old code we didn't *really* have to worry about sc->nr_to_scan dropping to negative, but now we do. ->nr_to_scan is unsigned so it would be a high positive value now so it's maybe a forever loop? I'm too lazy to verify... regards, dan carpenter