From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ed1-f70.google.com (mail-ed1-f70.google.com [209.85.208.70]) by kanga.kvack.org (Postfix) with ESMTP id AB5FA6B0010 for ; Mon, 16 Jul 2018 12:23:39 -0400 (EDT) Received: by mail-ed1-f70.google.com with SMTP id d30-v6so10170101edd.0 for ; Mon, 16 Jul 2018 09:23:39 -0700 (PDT) Received: from mx1.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id m2-v6si10166510edi.372.2018.07.16.09.23.38 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 16 Jul 2018 09:23:38 -0700 (PDT) Date: Mon, 16 Jul 2018 18:23:37 +0200 From: Michal Hocko Subject: Re: Caching/buffers become useless after some time Message-ID: <20180716162337.GY17280@dhcp22.suse.cz> References: <20180712113411.GB328@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: Marinko Catovic Cc: linux-mm@kvack.org On Mon 16-07-18 17:53:42, Marinko Catovic wrote: > I can provide further data now, monitoring vmstat: > > https://pastebin.com/j0dMGBe4 .. 1 day later, 600MB/13GB in use, 35GB free > https://pastebin.com/N011kYyd .. 1 day later, 300MB/10GB in use, 40GB free, > performance becomes even worse > > the issue raises up again, I would have to drop caches by now to restore > normal usage for another day or two. > > Afaik there should be no reason at all to not have the buffers/cache fill > up the entire memory, isn't that true? > There is to my knowledge almost no O_DIRECT involved, also as mentioned > before: when dropping caches > the buffers/cache usage would eat up all RAM within the hour as usual for > 1-2 days until it starts to go crazy again. > > As mentioned, the usage oscillates up and down instead of up until all RAM > is consumed. > > Please tell me if there is anything else I can do to help investigate this. Do you have periodic /proc/vmstat snapshots I have asked before? -- Michal Hocko SUSE Labs