From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Fri, 23 Jun 2000 18:56:44 +0100 From: Stephen Tweedie Subject: Re: [RFC] RSS guarantees and limits Message-ID: <20000623185644.C10285@redhat.com> References: <85256907.004D1292.00@D51MTA03.pok.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <85256907.004D1292.00@D51MTA03.pok.ibm.com>; from frankeh@us.ibm.com on Fri, Jun 23, 2000 at 10:01:14AM -0400 Sender: owner-linux-mm@kvack.org Return-Path: To: frankeh@us.ibm.com Cc: linux-mm@kvack.org List-ID: Hi, On Fri, Jun 23, 2000 at 10:01:14AM -0400, frankeh@us.ibm.com wrote: > How is shared memory accounted for? Shared memory has nothing to do with RSSes --- the RSS is strictly a per-process concept. If a process exhausts its RSS, then pages are removed from that process's working set, but these pages are not immediately evicted from physical memory. If the page is faulted back in before being finally evicted from memory, ten there is no disk IO involved. The advantage of the RSS limit here is that the pages which are evicted from working set but not from memory are MUCH easier for the VM to evict later if we run out of physical free pages. If we are under memory pressure, then the RSS limit causes us to prefer to page out the pages of processes who are above their RSS limit. --Stephen -- 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.eu.org/Linux-MM/