From owner-svn-src-head@FreeBSD.ORG Tue Jun 18 21:29:07 2013 Return-Path: Delivered-To: svn-src-head@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) by hub.freebsd.org (Postfix) with ESMTP id AA16D42B for ; Tue, 18 Jun 2013 21:29:07 +0000 (UTC) (envelope-from jroberson@jroberson.net) Received: from mail-pd0-f171.google.com (mail-pd0-f171.google.com [209.85.192.171]) by mx1.freebsd.org (Postfix) with ESMTP id 84C1B1609 for ; Tue, 18 Jun 2013 21:29:07 +0000 (UTC) Received: by mail-pd0-f171.google.com with SMTP id y14so4365289pdi.16 for ; Tue, 18 Jun 2013 14:29:07 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=date:from:x-x-sender:to:cc:subject:in-reply-to:message-id :references:user-agent:mime-version:content-type:x-gm-message-state; bh=k3iDFc0wZJ+EaNtFRc3LDz7ilqThRPbHK+Qt0oChQ1M=; b=I2eSWSfolJBwiO2yBvWHmqW9q6K8SxF0QKvl7dvPx65GgSzbcB6Dhe875Pbt1WJ8Xb jyOgquzpaPgeXLXR0SWEmIk8WRRQrAjRe5QC0v6un2BYAwIj9ZcvtxRQ5ZlcaR4dZ4D1 o49SktBv3jdNH0nu24dbXFn2Z5CjNVgN2Qc3DpifmpGYX+8lKQuxu5KaNCZ1Nxq3bWro Fxp4chNQxvdBN2rI+vvlCaU4IfvLx7k0BOrQiCHKcDoqA3DWbtSdOCfFA1tVO8yjfZR6 vcav5JU4Vt6SWKfCVRI+ynr31UECWj9eHKiCI52YmpJoTLkppZKpwdqLKSODnNTT0sYV X7cQ== X-Received: by 10.68.4.9 with SMTP id g9mr19018490pbg.217.1371590946902; Tue, 18 Jun 2013 14:29:06 -0700 (PDT) Received: from rrcs-66-91-135-210.west.biz.rr.com (rrcs-66-91-135-210.west.biz.rr.com. [66.91.135.210]) by mx.google.com with ESMTPSA id xj9sm19869773pbc.16.2013.06.18.14.29.04 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Tue, 18 Jun 2013 14:29:06 -0700 (PDT) Date: Tue, 18 Jun 2013 11:21:51 -1000 (HST) From: Jeff Roberson X-X-Sender: jroberson@desktop To: Alfred Perlstein Subject: Re: svn commit: r251894 - in head: lib/libmemstat sys/vm In-Reply-To: <51C04C77.7010907@mu.org> Message-ID: References: <201306180450.r5I4oKoY091256@svn.freebsd.org> <51C01964.1000006@freebsd.org> <20130618083733.GQ1400@FreeBSD.org> <51C04C77.7010907@mu.org> User-Agent: Alpine 2.00 (BSF 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed X-Gm-Message-State: ALoCoQm5WKNlCTf/6wkydreJrxzV89QYhQDme6lZJzk/wHz2kkRc+Ag2OTzupzFU0EqHAYthN5V8 Cc: src-committers@freebsd.org, Andre Oppermann , svn-src-all@freebsd.org, Gleb Smirnoff , svn-src-head@freebsd.org, Jeff Roberson X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 18 Jun 2013 21:29:07 -0000 On Tue, 18 Jun 2013, Alfred Perlstein wrote: > On 6/18/13 4:37 AM, Gleb Smirnoff wrote: >> On Tue, Jun 18, 2013 at 10:25:08AM +0200, Andre Oppermann wrote: >> A> There used to be a problem with per CPU caches accumulating large >> amounts >> A> of items without freeing back to the global (or socket) pool. >> A> >> A> Do these updates to UMA change this situation and/or do you have further >> A> improvements coming up? >> >> This is especially a problem with ZFS, which utilizes UMA extensively. >> >> IMHO, we need a flag for uma_zcreate() that would disable per CPU caches, >> so >> that certain zones (ZFS at least) would have them off. >> >> It might be a good idea to force this flag on every zone that has >> allocation >= >> then the page size. >> > What about people running with 256GB+ ram? Do they also want the per cpu > caches off? If you look at the new system there is a static threshold for the initial item size required for different sized per-cpu buckets. What might make sense is to tune this size based on available memory. For what it's worth I looked at solaris settings and they cache roughly 4x as much on a per-cpu basis. The new system should tend to cache less of large and infrequent allocations vs the old system. I can't say yet whether it is still a problem. I have an implementation of vmem to replace using vm_maps for kmem_map, buffer_map, etc. which may resolve the zfs allocation problems. I hope to get this in over the next few weeks. Thanks, Jeff > > -- > Alfred Perlstein > VP Software Engineering, iXsystems >