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 <brking at linux.vnet.ibm.com> > --- 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 <anton at samba.org> Anton
