From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anton Blanchard Subject: Re: [PATCH 3/5]: ipr: kexec boot speed improvements Date: Mon, 1 Dec 2014 07:43:19 +1100 Message-ID: <20141201074319.7ded3d8e@kryten> References: <53D6B2A4.4010102@linux.vnet.ibm.com> <20140827140630.1f0ee455@kryten> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: Received: from ozlabs.org ([103.22.144.67]:58764 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751650AbaK3UnV (ORCPT ); Sun, 30 Nov 2014 15:43:21 -0500 In-Reply-To: <20140827140630.1f0ee455@kryten> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Brian King Cc: "James E.J. Bottomley" , linux-scsi , Wendy Xiong , kexec@lists.infradead.org Hi Brian, > > Currently when performing a kexec boot with an ipr adapter, > > the adapter gets shutdown completely, flushing all write > > cache, as well as performing a full hardware reset of the card > > during the shutdown phase of the old kernel. This forces > > the new kernel to then wait for the adapter firmware to > > reinitialize, which slows down kexec boot. There is no > > need to do all of this on the newer ipr adapters, since they > > support the ability to cancel outstanding error buffers. > > > > This patch adds a special case for kexec boot to simply > > cancel these outstanding error buffers, and as long as > > there is no other I/O outstanding to the adapter, which > > there shouldn't be, place the adapter into a state > > where it has no memory of any DMA addresses from the old > > kernel, then disable the device. This significantly > > speeds up kexec boot, particularly in configurations with > > multiple ipr adapters. > > > > Signed-off-by: Brian King > > --- > > This reduces boot time on my box from 80 seconds to 34 seconds. ppc64 > kernel developers (who boot boxes continually) thank you! > > Tested-by: Anton Blanchard Just checking on this series. I'm very keen to see it go in since it is a huge improvement in boot time. Anton