From owner-freebsd-hackers@FreeBSD.ORG Sun Sep 28 01:56:13 2014 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 976841BD for ; Sun, 28 Sep 2014 01:56:13 +0000 (UTC) Received: from mail-ig0-f181.google.com (mail-ig0-f181.google.com [209.85.213.181]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 5F15DE05 for ; Sun, 28 Sep 2014 01:56:13 +0000 (UTC) Received: by mail-ig0-f181.google.com with SMTP id h18so1549071igc.2 for ; Sat, 27 Sep 2014 18:56:12 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc:content-type; bh=7zJx+v75//Lz8DK3p8hbBa8Bk3TdSky9JhOlgQSrSfs=; b=UG4WnVhEpA99zBjxbXXiSs6zSoy+wCHgXJ9CEqaYCozAuO4tSi2aWEbmoHK1n4BUQc 27UIJpoMM2+EL/M7ae2D386Sov60c/6/bxiPsE4obzDr7ETDph32qSnL74EST7LmQW5s E2osw7DUS3SWld1GZACriWsK8U4BLtbPGGT5MdkHvC4GIp7MmXQs+vAz39//C5p8Iihf lt6caGO7R0YV7gJK5p+1LLRgB+L4VcDhfHbhvdobYF9aTveUzLTExAg9emjt8gsluNiI rzy/QI/c4t44QW/g/9x1FlP8yCetgOz3RbF0DlVa9k3+tBSWb/S1NUr4BNkA1y7iPDFn QlXg== X-Gm-Message-State: ALoCoQmKb1t0HjE+3UNRfI1ALmo6zn+Mbd/MmkSiC8KjUyauTm3ZVDyGvU0EtYlLCpgG0X8/xYWz X-Received: by 10.50.20.4 with SMTP id j4mr42755112ige.13.1411869372468; Sat, 27 Sep 2014 18:56:12 -0700 (PDT) MIME-Version: 1.0 Received: by 10.107.9.67 with HTTP; Sat, 27 Sep 2014 18:55:52 -0700 (PDT) X-Originating-IP: [67.198.113.68] In-Reply-To: References: From: Bryan Venteicher Date: Sat, 27 Sep 2014 20:55:52 -0500 Message-ID: Subject: Re: Change uma_mtx to rwlock To: Steven Hartland Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Content-Filtered-By: Mailman/MimeDel 2.1.18-1 Cc: "freebsd-hackers@freebsd.org" X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 28 Sep 2014 01:56:13 -0000 On Sat, Sep 27, 2014 at 8:42 PM, Steven Hartland wrote: > Out of interest does that include ZFS and its UMA zones, as we're current= ly > investigating issues around this. > > =E2=80=8BYes, I believe this would include ZFS's zones too.=E2=80=8B > Regards > Steve > > ----- Original Message ----- From: "Bryan Venteicher" < > bryanv@daemoninthecloset.org> > To: > Sent: Sunday, September 28, 2014 1:59 AM > Subject: Change uma_mtx to rwlock > > > > Hi, >> >> I'd appreciate some comments attached patch that changes the uma_mtx to = a >> rwlock. >> >> At $JOB, we have machines with ~400GB RAM, with much of that being >> allocated through UMA zones. We've observed that timeouts were sometimes >> unexpectedly delayed by a half second or more. We tracked one of the >> reasons for this down to when the page daemon was running, calling >> uma_reclaim() -> zone_foreach(). zone_foreach() holds the uma_mtx while >> zone_drain()'ing each zone. If uma_timeout() fires, it will block on the >> uma_mtx when it tries to zone_timeout() each zone. >> >> > > ------------------------------------------------------------ > -------------------- > > > _______________________________________________ >> freebsd-hackers@freebsd.org mailing list >> http://lists.freebsd.org/mailman/listinfo/freebsd-hackers >> To unsubscribe, send any mail to "freebsd-hackers-unsubscribe@freebsd.or= g >> " >> >