From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 25 Aug 2004 13:54:57 -0700 From: William Lee Irwin III Subject: Re: Documentation/vm/balance really outdated Message-ID: <20040825205457.GJ2793@holomorphy.com> References: <20040825184520.GA23878@logos.cnet> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20040825184520.GA23878@logos.cnet> Sender: owner-linux-mm@kvack.org Return-Path: To: Marcelo Tosatti Cc: linux-mm@kvack.org, akpm@osdl.org List-ID: On Wed, Aug 25, 2004 at 03:45:20PM -0300, Marcelo Tosatti wrote: > The file Documentation/vm/balance was written by Kanoj in 2000, and > is completly outdated to what we have now. > Last paragraph: > pages_min/pages_low/pages_high/low_on_memory/zone_wake_kswapd: These are > per-zone fields, used to determine when a zone needs to be balanced. When > the number of pages falls below pages_min, the hysteric field low_on_memory > gets set. This stays set till the number of free pages becomes pages_high. > When low_on_memory is set, page allocation requests will try to free some > pages in the zone (providing GFP_WAIT is set in the request). Orthogonal > to this, is the decision to poke kswapd to free some zone pages. That > decision is not hysteresis based, and is done when the number of free > pages is below pages_low; in which case zone_wake_kswapd is also set. > Should we just remove it? pages_min, pages_low, and pages_high are still in use, but with more precisely-defined semantics. low_on_memory is gone, and min_free_kb, overcommit_memory, and swappiness have arrived for different purposes. I find the value of this documentation rather unclear particularly given that it's not been examined in so long. Maybe kerneldoc is the way. -- wli -- 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: aart@kvack.org