From owner-svn-src-all@freebsd.org Mon Nov 2 03:29:30 2015 Return-Path: Delivered-To: svn-src-all@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 6CE62A24BD0; Mon, 2 Nov 2015 03:29:30 +0000 (UTC) (envelope-from yaneurabeya@gmail.com) Received: from mail-pa0-x235.google.com (mail-pa0-x235.google.com [IPv6:2607:f8b0:400e:c03::235]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 34FD7162A; Mon, 2 Nov 2015 03:29:30 +0000 (UTC) (envelope-from yaneurabeya@gmail.com) Received: by pasz6 with SMTP id z6so133817696pas.2; Sun, 01 Nov 2015 19:29:29 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=content-type:mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=KcoGsHNLX26JNxUldatFyiJnP65GvtTKAS+F3/uBZPI=; b=XvQkl0QgrS7x0w1z5YZomdHV0paGXrE1Uy0AYWZ4yF2HXmlfUcrwKzvd6+B2186Yz0 3RcPurIzJPXGosp+CXJy+VKsiACobqQ/s08I5uA5TKvPVZelAl7ks/oY2Se5hmLtcd2Z dhIiD6m7SUR/oT32PI6NdOnn1nuOinjmExfwr7/2UNIdioj6sds1ZnLL+kFglMaFSG4R GHhkT5ROtCu00gbPEiMqsDl5Jg++LkDWmhhS/2jJwagbOSFHng8DiN7uuBHPl40sxNS1 5wLJZ9sy66MPKHxK6hIZtz8EHvp3gJYkwY6LrERf2O757owpioAayXQgD8jFvLGE1YnA 0oiQ== X-Received: by 10.69.26.7 with SMTP id iu7mr24620153pbd.27.1446434969814; Sun, 01 Nov 2015 19:29:29 -0800 (PST) Received: from ?IPv6:2601:601:800:126d:541b:f764:9c9c:ea2b? ([2601:601:800:126d:541b:f764:9c9c:ea2b]) by smtp.gmail.com with ESMTPSA id ia3sm20893264pbb.5.2015.11.01.19.29.28 (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Sun, 01 Nov 2015 19:29:29 -0800 (PST) Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 8.2 \(2104\)) Subject: Re: svn commit: r289279 - in head/sys: kern vm From: NGie Cooper In-Reply-To: Date: Sun, 1 Nov 2015 19:29:28 -0800 Cc: Jeff Roberson , Mark Johnston , Warner Losh , benno , "src-committers@freebsd.org" , "svn-src-all@freebsd.org" , "svn-src-head@freebsd.org" Content-Transfer-Encoding: quoted-printable Message-Id: References: <201510140210.t9E2A79H056595@repo.freebsd.org> To: Adrian Chadd X-Mailer: Apple Mail (2.2104) X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 02 Nov 2015 03:29:30 -0000 > On Nov 1, 2015, at 19:20, Adrian Chadd wrote: >=20 > hiya jeff, >=20 > this broke low-memory, no-swap boards (eg MIPS.) >=20 > On a MIPS board (carambola2) with 32MB of RAM, just scp'ing a kernel > into the rootfs on USB hangs the system. After doing some digging, I > found this: >=20 >=20 > INTERNAL: Allocating one item from buf free cache(0x83fea7e0) > uma_zalloc_arg: Bucketzone returned NULL > INTERNAL: Allocating one item from buf free cache(0x83fea7e0) > uma_zalloc_arg: Bucketzone returned NULL >=20 > .. and it was just stuck in a loop trying to allocate them, failing, > and trying to allocate them again. >=20 > I'll see if I can reproduce it with a qemu emulator with sufficiently > low RAM so you don't need a MIPS router to reproduce it. >=20 > It's sufficient to just start the scp; it runs out of RAM within a > couple of seconds. >=20 > Any ideas? What happens if you change vfs.maxbufspace ? The reason that I=E2=80=99m noting is that (if I=E2=80=99m reading the = code correctly), it=E2=80=99s now allocating 16 clean queues instead of = 1 and each is up to vfs.maxbufspace size, which is 256MB per queue based = on this line: + clean_queues =3D MIN(howmany(maxbufspace, 256*1024*1024), = CLEAN_QUEUES); The 256MB amount seems like it should be a tunable, as well as the = CLEAN_QUEUES #define=E2=80=A6 it=E2=80=99s a bit high for low memory = platforms, i.e. platforms with <372MB of scratch space to play around = with I=E2=80=99m guessing=E2=80=A6 Thanks, -NGie=