On Tue, 31 Dec 2019 17:03:23 +0000 Ben Hutchings <b...@decadent.org.uk> wrote: > On Mon, 2019-12-30 at 00:03 -0800, Josh Triplett wrote: > > Source: linux > > Severity: wishlist > > > > A few requests for changes to the cloud configuration: > > Most of this looks reasonable, but: > > > - Please disable CONFIG_ACPI_BGRT; a cloud kernel doesn't need to spend > > time or code space looking for a boot logo that won't exist. > > > > - Please disable the CONFIG_CPU_SUP_* options for CPUs that no cloud > > provider uses. > > > > - Please disable CONFIG_GNSS_*, which won't be hooked up to a cloud > > server. > > > > - Please disable CONFIG_GTP for the same reason. > > > > - Please configure CONFIG_INPUT_MOUSEDEV as a module, not built-in, as > > most cloud servers won't have a mouse and probing for one takes time. > > > > - Please consider changing the default kernel compression to GZIP, which > > decompresses faster and thus boots faster. > > LZO or LZ4 could be even faster.
It might. GZIP seemed like a more reasonable tradeoff to request, but I'd be all for LZ4 if that seems reasonable to you. That is indeed the fastest option (see https://smackerelofopinion.blogspot.com/2019/09/ for data to back that up). It might even be worth switching to LZ4 on the standard Debian kernels as well. > > - Please change CONFIG_NET_MPLS_GSO from y to m (and consider doing this > > for the non-cloud kernel too); it doesn't need to be built into the > > kernel. > > Unfortunately nothing will load it if it's a module. It's also a tiny > piece of code. This might still be justifiable on the basis of > reducing the default attack surface though. I didn't realize it didn't autoload. But yes, it seems quite unlikely to be needed. > > - Please change CONFIG_NF_NAT_* and CONFIG_NF_MASQUERADE_* from y to m, > > as many systems won't need those modules and shouldn't need to load > > their code. > > Some of those are boolean options, and I believe all of those that can > be modular already are. You'll have to be more specific. I'd forgotten that several options became booleans and their code got merged into parent modules that are already modularized; nevermind on this one. > > - Please compile in the NVME driver and the EXT4 filesystem; this will > > allow many cloud systems to avoid using an initramfs at all, which > > substantially improves boot time. > > > > - Please disable CONFIG_NUMA_EMU, only used to create fake-NUMA systems > > for debugging. > > > > - Please disable CONFIG_PCIPCWATCHDOG, CONFIG_PPS, and CONFIG_RMI4_*, > > which won't appear on a cloud server. > > Hyper-V and KVM both support PTP clocks, and PTP_1588_CLOCK selects > PPS. Ah, I didn't realize Hyper-V provided a PTP device; that makes sense. - Josh Triplett
