From mboxrd@z Thu Jan 1 00:00:00 1970 From: "H. Peter Anvin" Subject: Re: [PATCH 00/14] Present useful limits to user (v2) Date: Fri, 15 Jul 2016 13:54:44 -0700 Message-ID: <201607152054.u6FKslD1005327__10643.7137387276$1468631361$gmane$org@mail.zytor.com> References: <1468578983-28229-1-git-send-email-toiwoton@gmail.com> <20160715124330.GR30154@twins.programming.kicks-ass.net> <28b4b919-4f50-d9f6-c5e1-d1e92ea1ba1c@gmail.com> <20160715135956.GA3115@twins.programming.kicks-ass.net> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Return-path: Received: from kanga.kvack.org ([205.233.56.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1bOE6H-0004Fx-KH for glkm-linux-mm-2@m.gmane.org; Sat, 16 Jul 2016 03:09:01 +0200 Received: from mail-qt0-f198.google.com (mail-qt0-f198.google.com [209.85.216.198]) by kanga.kvack.org (Postfix) with ESMTP id 52F0E6B0266 for ; Fri, 15 Jul 2016 16:58:11 -0400 (EDT) Received: by mail-qt0-f198.google.com with SMTP id c52so224953367qte.2 for ; Fri, 15 Jul 2016 13:58:11 -0700 (PDT) Received: from mail.zytor.com (torg.zytor.com. [2001:1868:205::12]) by mx.google.com with ESMTPS id f84si3039299ywc.105.2016.07.15.13.58.06 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 15 Jul 2016 13:58:07 -0700 (PDT) In-Reply-To: <20160715135956.GA3115@twins.programming.kicks-ass.net> Sender: owner-linux-mm@kvack.org List-ID: To: Peter Zijlstra , Topi Miettinen Cc: linux-kernel@vger.kernel.org, Jonathan Corbet , Tony Luck , Fenghua Yu , Alexander Graf , Paolo Bonzini , Radim Kr??m???? , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Thomas Gleixner , Ingo Molnar , "maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" , Doug Ledford , Sean Hefty , Hal Rosenstock , Mike Marciniszyn , Dennis Dalessandro , Christian Benvenuti , Dave Goodell ,Johannes Weiner ,Alexei Starovoi= tov ,Arnaldo Carvalho de Melo ,Alexander= Shishkin ,Balbir Singh ,Markus Elfring ,"David S. Mille= r" ,Nicolas Dichtel ,Andr= ew Morton ,Konstantin Khlebnikov ,Jiri Slaby ,Cyrill Gorcunov ,M= ichal Hocko ,Vlastimil Babka ,Dave Hanse= n ,Greg Kroah-Hartman ,Dan Carpenter ,Michael Kerrisk ,"Kirill A. Shutemov" ,Ma= rcus Gelderie ,Vladimir Davydov ,Joe Perches ,Frederic Weisbecker = ,Andrea Arcangeli ,! "Eric W. Biederman" ,Andi Kleen ,Oleg N= esterov ,Stas Sergeev ,Amanieu d'Antras ,Richard Weinberger ,Wang Xiaoqiang ,Helge Deller ,Mateusz Guzik ,Alex Thorlton ,Ben Segall = ,John Stultz ,Rik van Riel ,Eric= B Munson ,Alexey Klimov ,Che= n Gang ,Andrey Ryabinin ,David Rientjes ,Hugh Dickins ,A= lexander Kuleshov ,"open list:DOCUMENTATION" ,"open list:IA64 (Itanium) PLATFORM" ,"open list:KERNEL VIRTUAL MACHINE (KVM) FOR POWERPC" ,"open list:KERNEL VIRTUAL MACHINE (KVM)" ,"open list:LINUX FOR POWERPC! (32-BIT AND 64-BIT)" ,"open list:INFINIBAND SUBSYS= TEM" ,"open list:FILESYSTEMS (VFS and infrast= ructure)" ,"open list:CONTROL GROUP (CGROU= P)" ,"open list:BPF (Safe dynamic programs and t= ools)" ,"open list:MEMORY MANAGEMENT" Message-ID: On July 15, 2016 6:59:56 AM PDT, Peter Zijlstra wr= ote: >On Fri, Jul 15, 2016 at 01:52:48PM +0000, Topi Miettinen wrote: >> On 07/15/16 12:43, Peter Zijlstra wrote: >> > On Fri, Jul 15, 2016 at 01:35:47PM +0300, Topi Miettinen wrote: >> >> Hello, >> >> >> >> There are many basic ways to control processes, including >capabilities, >> >> cgroups and resource limits. However, there are far fewer ways to >find out >> >> useful values for the limits, except blind trial and error. >> >> >> >> This patch series attempts to fix that by giving at least a nice >starting >> >> point from the highwater mark values of the resources in question. >> >> I looked where each limit is checked and added a call to update >the mark >> >> nearby. >> >=20 >> > And how is that useful? Setting things to the high watermark is >> > basically the same as not setting the limit at all. >>=20 >> What else would you use, too small limits? > >That question doesn't make sense. > >What's the point of setting a limit if it ends up being the same as >no-limit (aka unlimited). > >If you cannot explain; and you have not so far; what use these values >are, why would we look at the patches. One reason is to catch a malfunctioning process rather than dragging the = whole system down with it. It could also be useful for development. --=20 Sent from my Android device with K-9 Mail. Please excuse brevity and form= atting. -- 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