From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr0-f200.google.com (mail-wr0-f200.google.com [209.85.128.200]) by kanga.kvack.org (Postfix) with ESMTP id BA2E56B0033 for ; Fri, 24 Nov 2017 07:44:32 -0500 (EST) Received: by mail-wr0-f200.google.com with SMTP id r2so8948093wra.4 for ; Fri, 24 Nov 2017 04:44:32 -0800 (PST) Received: from mx2.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id q50si3425318edq.170.2017.11.24.04.44.31 for (version=TLS1 cipher=AES128-SHA bits=128/128); Fri, 24 Nov 2017 04:44:31 -0800 (PST) Date: Fri, 24 Nov 2017 13:44:29 +0100 From: Michal Hocko Subject: Re: Re: [PATCH 1/1] stackdepot: interface to check entries and size of stackdepot. Message-ID: <20171124124429.juonhyw4xbqc65u7@dhcp22.suse.cz> References: <20171123162835.6prpgrz3qkdexx56@dhcp22.suse.cz> <1511347661-38083-1-git-send-email-maninder1.s@samsung.com> <20171124094108epcms5p396558828a365a876d61205b0fdb501fd@epcms5p3> <20171124095428.5ojzgfd24sy7zvhe@dhcp22.suse.cz> <20171124115707epcms5p4fa19970a325e87f08eadb1b1dc6f0701@epcms5p4> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171124115707epcms5p4fa19970a325e87f08eadb1b1dc6f0701@epcms5p4> Sender: owner-linux-mm@kvack.org List-ID: To: Vaneet Narang Cc: Dmitry Vyukov , Maninder Singh , "kstewart@linuxfoundation.org" , "gregkh@linuxfoundation.org" , "jkosina@suse.cz" , "pombredanne@nexb.com" , "jpoimboe@redhat.com" , "akpm@linux-foundation.org" , "vbabka@suse.cz" , "guptap@codeaurora.org" , "vinmenon@codeaurora.org" , AMIT SAHRAWAT , PANKAJ MISHRA , Lalit Mohan Tripathi , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , kasan-dev On Fri 24-11-17 11:57:07, Vaneet Narang wrote: [...] > > OK, so debugging a debugging facility... I do not think we want to > > introduce a lot of code for something like that. > > We enabled stackdepot on our system and realised, in long run stack depot consumes > more runtime memory then it actually needs. we used shared patch to debug this issue. > stack stores following two unique entries. Page allocation done in interrupt > context will generate a unique stack trace. Consider following two entries. [...] > We have been getting similar kind of such entries and eventually > stackdepot reaches Max Cap. So we found this interface useful in debugging > stackdepot issue so shared in community. Then use it for internal debugging and provide a code which would scale better on smaller systems. We do not need this in the kernel IMHO. We do not merge all the debugging patches we use for internal development. -- Michal Hocko SUSE Labs -- 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