From owner-freebsd-hackers@FreeBSD.ORG Tue Jun 12 14:52:43 2012 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 9CD11106564A for ; Tue, 12 Jun 2012 14:52:43 +0000 (UTC) (envelope-from freebsd@damnhippie.dyndns.org) Received: from qmta07.emeryville.ca.mail.comcast.net (qmta07.emeryville.ca.mail.comcast.net [76.96.30.64]) by mx1.freebsd.org (Postfix) with ESMTP id 7B6FA8FC21 for ; Tue, 12 Jun 2012 14:52:43 +0000 (UTC) Received: from omta17.emeryville.ca.mail.comcast.net ([76.96.30.73]) by qmta07.emeryville.ca.mail.comcast.net with comcast id MRnU1j0021afHeLA7SrdHJ; Tue, 12 Jun 2012 14:51:37 +0000 Received: from damnhippie.dyndns.org ([24.8.232.202]) by omta17.emeryville.ca.mail.comcast.net with comcast id MSrc1j01H4NgCEG8dSrdyY; Tue, 12 Jun 2012 14:51:37 +0000 Received: from [172.22.42.240] (revolution.hippie.lan [172.22.42.240]) by damnhippie.dyndns.org (8.14.3/8.14.3) with ESMTP id q5CEpYjZ032108; Tue, 12 Jun 2012 08:51:35 -0600 (MDT) (envelope-from freebsd@damnhippie.dyndns.org) From: Ian Lepore To: Wojciech Puchar In-Reply-To: References: <1339259223.36051.328.camel@revolution.hippie.lan> <20120609165217.GO85127@deviant.kiev.zoral.com.ua> Content-Type: text/plain; charset="us-ascii" Date: Tue, 12 Jun 2012 08:51:34 -0600 Message-ID: <1339512694.36051.362.camel@revolution.hippie.lan> Mime-Version: 1.0 X-Mailer: Evolution 2.32.1 FreeBSD GNOME Team Port Content-Transfer-Encoding: 7bit Cc: Konstantin Belousov , freebsd-hackers@freebsd.org Subject: Re: wired memory - again! X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 12 Jun 2012 14:52:43 -0000 On Sat, 2012-06-09 at 22:45 +0200, Wojciech Puchar wrote: > > > > First, all memory allocated by UMA and consequently malloc(9) is > > wired. In other words, almost all memory used by kernel is accounted > > as wired. > > > yes i understand this. still i found no way how to find out what allocated > that much. > > > > Second, the buffer cache wires the pages which are inserted into VMIO > > buffers. So your observation is basically right, cached buffers means > > what are exactly "VMIO" buffers. i understand that page must be wired WHEN > doing I/O. > But i have too much wired memory even when doing no I/O at all. I agree, this is The Big Question for me. Why does the system keep wired writable mappings of the buffers in kva after the IO operations are completed? If it did not do so, it would fix the instruction-cache-disabled bug that kills performance on VIVT cache architectures (arm and mips) and it would reduce the amount of wired memory (that apparently doesn't need to be wired, unless I've missed the implications of a previous reply in this thread). -- Ian