From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ob0-f176.google.com (mail-ob0-f176.google.com [209.85.214.176]) by kanga.kvack.org (Postfix) with ESMTP id A79986B0005 for ; Wed, 10 Feb 2016 14:11:28 -0500 (EST) Received: by mail-ob0-f176.google.com with SMTP id ba1so41369530obb.3 for ; Wed, 10 Feb 2016 11:11:28 -0800 (PST) Received: from alln-iport-7.cisco.com (alln-iport-7.cisco.com. [173.37.142.94]) by mx.google.com with ESMTPS id v83si795170oig.31.2016.02.10.11.11.27 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 10 Feb 2016 11:11:27 -0800 (PST) Subject: Re: computing drop-able caches References: <56AAA77D.7090000@cisco.com> <20160128235815.GA5953@cmpxchg.org> <56AABA79.3030103@cisco.com> <56AAC085.9060509@cisco.com> <20160129015534.GA6401@cmpxchg.org> <56ABEAA7.1020706@redhat.com> <56BB7BC7.4040403@cisco.com> <56BB7DDE.8080206@intel.com> From: Daniel Walker Message-ID: <56BB8B5E.0@cisco.com> Date: Wed, 10 Feb 2016 11:11:26 -0800 MIME-Version: 1.0 In-Reply-To: <56BB7DDE.8080206@intel.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Dave Hansen , "Khalid Mughal (khalidm)" , Rik van Riel , Johannes Weiner Cc: Alexander Viro , Michal Hocko , Andrew Morton , "linux-fsdevel@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , "xe-kernel@external.cisco.com" On 02/10/2016 10:13 AM, Dave Hansen wrote: > On 02/10/2016 10:04 AM, Daniel Walker wrote: >>> [Linux_0:/]$ echo 3 > /proc/sys/vm/drop_caches >>> [Linux_0:/]$ cat /proc/meminfo >>> MemTotal: 3977836 kB >>> MemFree: 1095012 kB >>> MemAvailable: 1434148 kB >> I suspect MemAvailable takes into account more than just the droppable >> caches. For instance, reclaimable slab is included, but I don't think >> drop_caches drops that part. > There's a bit for page cache and a bit for slab, see: > > https://kernel.org/doc/Documentation/sysctl/vm.txt > > Ok, then this looks like a defect then. I would think MemAvailable would always be smaller then MemFree (after echo 3 > /proc/sys/vm/drop_caches).. Unless there is something else be accounted for that we aren't aware of. Daniel -- 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