From mboxrd@z Thu Jan 1 00:00:00 1970 From: Laurent DENIEL Subject: Re: [Bonding-devel] Re: [SET 2][PATCH 2/8][bonding] Propagating master'ssettings toslaves Date: Mon, 11 Aug 2003 19:31:25 +0200 Sender: netdev-bounce@oss.sgi.com Message-ID: <3F37D2ED.B4B9223C@thalesatm.com> References: <200308111720.38472.shmulik.hen@intel.com> <1060612481.1034.15.camel@jzny.localdomain> <200308111925.38278.shmulik.hen@intel.com> <3F37C7C3.7070807@pobox.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Cc: shmulik.hen@intel.com, hadi@cyberus.ca, bonding-devel@lists.sourceforge.net, netdev@oss.sgi.com Return-path: To: Jeff Garzik Errors-to: netdev-bounce@oss.sgi.com List-Id: netdev.vger.kernel.org Jeff Garzik a =E9crit : >=20 > The answer is, like life, it's a balance. >=20 > As a general rule, we do prefer to move all code possible out of the > Linux kernel. We have even created "initramfs", which for 2.7, will be > used as a vehicle to move code from the kernel to userspace, that > previously had to be in the kernel only because it was a task that "had > to be performed at boot time". >=20 > However, one must consider > (1) does moving code to userspace create any security holes? > (2) does moving code to userspace dramatically increase the number of > context switches? > (3) does moving code to userspace violate some atomicity that being > inside the kernel guarantees? You forgot one important aspect :=20 (4) does moving code to userspace break compatibility (or behavior)=20 with user land applications (or systems) What can one do if say, kernel 2.[4|5] switches the NIC in 10 mseconds=20 while kernel 2.7 with user land daemon switches in a few seconds ?=20 nothing but stay with the previous version or fork the driver development= ;-( But I agree that it is interesting to do some stuff at user land, and if=20 the bonding had an option to disable the automatic failover policy,=20 this could be implemented with trigger towards user land application that= =20 could use an ioctl call to switch to the appropriate NIC according to=20 the user lan configuration ... But the fast and simple failover policy shall remain in kernel code. Laurent