From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751589AbcFNI23 (ORCPT ); Tue, 14 Jun 2016 04:28:29 -0400 Received: from mail-db3on0138.outbound.protection.outlook.com ([157.55.234.138]:27575 "EHLO emea01-db3-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750751AbcFNI20 (ORCPT ); Tue, 14 Jun 2016 04:28:26 -0400 Authentication-Results: spf=none (sender IP is ) smtp.mailfrom=VDavydov@virtuozzo.com; Date: Tue, 14 Jun 2016 11:13:12 +0300 From: Vladimir Davydov To: Christoph Lameter CC: Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , , Subject: Re: [PATCH RFC] slub: reap free slabs periodically Message-ID: <20160614081312.GL30465@esperanza> References: <1465575243-18882-1-git-send-email-vdavydov@virtuozzo.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: X-Originating-IP: [195.214.232.10] X-ClientProxiedBy: VI1PR0901CA0061.eurprd09.prod.outlook.com (2603:10a6:800:a::29) To AM3PR08MB0577.eurprd08.prod.outlook.com (2a01:111:e400:c408::11) X-MS-Office365-Filtering-Correlation-Id: d601b4cd-63a2-4534-fb8f-08d3942bbd40 X-Microsoft-Exchange-Diagnostics: 1;AM3PR08MB0577;2:v/fcXGEY8BJW7KN8Dug8Z66s0zV06WbXG6pRYPU90whwMCjRxomWrr2k8jTyeGY75o1FG1ILoiilI2HWUEblyVT+Ij/waFdZTuaz1bXF+99RrQ5lAjqD8/Q5PuNmnqpK8DFT0Ep/4tupPY+yQeY0DBHfV8z2z4pMeaCi0K/s38kkaLr45DdCOYeNdTFDyntk;3:mHGdg4Nfs/mZpVrQAyFKlM3iCvZy9WrYbPo2mh+7oaOX6bNOyPe5GfNx2hhZz5kWqwLzKXoUFaAAdedXdF4U18HH9ApozkhsCmZdd6q177EXRUgcZiZOdVyicEEnKBqw;25:gmwEt4ei32GhzuE39uET60CIbA1aFrq+DHzNVqpo8TpMdvMX95vzVoDkHwbr0xrpHT+3u0zsaGh5t3pqurzsr6GLpmy1BAmN4mE2eDMq/unDiN28MAWbty0xzQ9zjExRMpP9xFwTbHmN8r0zI4zZ3ACBs2lNirdvXQIgNCvdOWIVvc+iuEZm4Z+vBtlu9lWr/JPzbVBEGjsqR56bcTpiQIgvDsaUU+V42hQQ9OfLJJG3+u7IRErR7IbISXOPKEIBO+ksAo59FKmbBvvuS1W6AI/H4JDvoyNzNADLiJR7LdxuiipshMiPAkGHImDzzRfIo58vOrj7mi1hC7NHvL7U1REsbZHb0/yitA9Tsx7zF/kz7halprTTC5tcbcuWiDJ0nKb7uN1EYB8adkQGgkYMW56Tjkvg1OGVk2+i0vwGvU0= X-Microsoft-Antispam: UriScan:;BCL:0;PCL:0;RULEID:;SRVR:AM3PR08MB0577; 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X-Microsoft-Exchange-Diagnostics: =?us-ascii?Q?1;AM3PR08MB0577;23:WRv8HesctW2h4AvmcEV4aOcw/nVpuGrY8ZZZWBmj2?= =?us-ascii?Q?zMdK1osQi8b1TkvxEEZkRxvuHJH0eZhN3vliVQFeLYlEedpWzlAWECokUUDW?= =?us-ascii?Q?fd4qYKokwA8aNAS8bWLEqoyhtgUeeqqVkWN9j+cWyoY0l8OrNtXbGw51Ao5M?= =?us-ascii?Q?Zjox20zvAfGDC/A3w5J6CBclG/YaSw8VyIHfBvf97mJlx+LioV9kXXSAkMd9?= =?us-ascii?Q?gVTuIe16nvugbXt13iPCAS/IhNivAh0CsrI4ZC9/x65oY2N6UmYmpRUg7wAy?= =?us-ascii?Q?2/YQuEUfjnnVsGDx5UXHUlN9nFDSHJxGyrzbRQD+qgTJjAD3uOCNAfpilHx9?= =?us-ascii?Q?P9aOKJg/y6f0VV8U6T3Te4AyBwn3o8ixZGN27wzKl4pXUlbGa+SYxMbwZ/2w?= =?us-ascii?Q?1mU1sSbbGDSqFPsQRB0vU3SwvfnHqd9XIm+WmCTJKTWBcMbs03+BPGZDY1kW?= =?us-ascii?Q?WidDKrP8/kCvsSdo9zMXeoJ55XgcjURbmuNUop2e5gE4Cu3N8H6LOC67Q8TK?= =?us-ascii?Q?/tY+nLqeKEDcS9ESDbjoysPlHEwRjOocofbz5kC0rpaNo6pKdKriMVzgh3oK?= =?us-ascii?Q?31ak6/f9j7faI59tkOL8nsPgwUb0FajOD5pwTZrA+N/FfkbfsFoIsf/1QKpC?= =?us-ascii?Q?BOfHRchmFjprnOFF52qQoTz10zqb6Hh7qiVUx3FFpmDo3egygGDYM1FyWedZ?= =?us-ascii?Q?tq/y31n9gmTcltbA5M+MQwFzDKaN2kJvCRYWkSdCiqLFWgMAE6n5AzNq9sRd?= =?us-ascii?Q?rQdx3/yOwJKn/bD56lxA4vRcw+G2Cp5FRI5MwCX84oHZPFnx83XxBWQiORYF?= =?us-ascii?Q?qAY+vuaPV6iItFoOlVfpBD5RdMo5hWVhVTjDOzu1w+2vVgmmgr5a0JZO8imI?= =?us-ascii?Q?lpwphyVjbQeX1wwDqSq6kiI3JOZNo/jmRDp0TddL7k5FmOb1XdlZr3h9DkVN?= =?us-ascii?Q?FQyFUgjc93BCMVJFKTaO/Pln1AwRNk3kOap+DE2g5xI7P9IomTPYmQvQbY4G?= =?us-ascii?Q?HxecIROlcfFEwOGIyXkOTgChN9M9vAaztdnmQJpXBMSfDWAZbFGtM8GBFa5m?= =?us-ascii?Q?RQwloA=3D?= X-Microsoft-Exchange-Diagnostics: 1;AM3PR08MB0577;6:yea8UlSVxMy/RAeZrBHE2rrzQ9fkP31zXSfANDZbmqegsVTiHJs6erGAd1s4yMKITT0IFJCxGrm5L6KF5dGr3rXoyTSQbisDc1rRJmYUl99FcaM3vFT9N8hF3OoLS6ogvGbgUXoNBolduwbtZdJcI5XiSWCOi5HavFaSqboNGxlQB/oE7GbAWG0m9+DHJQAytf2DiJrwF7AUl+NGeaBfMC3HPdfYhzTvNZDXm0KKKq8pJ6XClowj64GAdx446Tde7M/eevBI1JRSj6BA0DNN9nhCDrEG2L3Jar9LuVXXNjY=;5:CltUCykNBOLdfuA3Lv2x4iwbG64nZmMrlyveZwCSkjamVCWnmlAO5pQvY/I5cEc7miDQdtDzqFqKBcooJ/5rD2BeM8t+MN6nDSRI/71MzxK1H2FuzLUxeiushznzNsOSsJ0SxEh4AbhkaFCJNr+wpA==;24:yMmOR4QCjALqdNAKS83CWWp60rYvxiN6qSbEooZbZ/ZfFQs610zxke22Rr6AUfmtr/3OcPjUnoCcDo9ifGaCOpsPnzHgHmVaq7ic3VdMuWE=;7:7m9g9FzE5auV/ksYVxZm8tDofj0Jgo8l5aubrOVSN5euMJbtYAEWC6VUVwK7RZdL4ppXxnUqmYcalBELqASJyg/50VAn3uS0LSTWvogf4eh+iT68kdVEXTC1AfQrqFpcPikXmwA1+b0B7UfNMIMGe/PcBBD++Py0cLI7ufPoDG/tWyu3z/1cQQqbPwFPqkwAyM5RIlbZgM8epaRmmHSuew==;20:/jfjt3tFX85KCsFD9Hueff6jzKes2Qr3Ktq+irGbneREkLsmfjo4DWV0+4MffNyUHn6VmrQRuP/xSlhffcqOR0UgCtM8rjt/hoVA+KfNafCSiC9Xp1pI5jVUItcNV/8xBili78QSzQBglFpGBebWw859kioU457bQD+WLv6LfFo= SpamDiagnosticOutput: 1:99 SpamDiagnosticMetadata: NSPM X-OriginatorOrg: virtuozzo.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 14 Jun 2016 08:13:15.9991 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-Transport-CrossTenantHeadersStamped: AM3PR08MB0577 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jun 10, 2016 at 04:32:26PM -0500, Christoph Lameter wrote: > One reason for SLUBs creation was the 2 second scans in SLAB which causes > significant disruption of latency sensitive tasksk. That's not good, indeed. > > You can simply implement a reaper in userspace by running > > slabinfo -s > > if you have to have this. Doing this periodically would probably hurt performance of active caches as 'slabinfo -s' shrinks all slabs unconditionally, even if they are being actively used. OTOH, one could trigger shrinking slabs only on memory pressure. That would require yet another daemon tracking the system state, but it is doable I guess. Thanks a lot for your input, Christoph. > > There is no need to duplicate SLAB problems.