Re: What belongs in the Debian cloud kernel?
On Wed, Apr 01, 2020 at 03:15:37PM -0400, Noah Meyerhans wrote:
> There are open bugs against the cloud kernel requesting that
> configuration options be turned on there. [1][2][3]
<snip>
> 1. https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=952108
> 2. https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=955366
> 3. https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=955232
So, the discussion thus far has focused on these specific requests more
than I had hoped. So for now, so we can deal with the current requests,
here's what happens if we enable them:
These are the kernel .config changes:
+CONFIG_VHOST_SCSI=m
+CONFIG_KSM=y
+CONFIG_NET_9P=m
+CONFIG_NET_9P_VIRTIO=m
+# CONFIG_NET_9P_XEN is not set
+# CONFIG_NET_9P_DEBUG is not set
+CONFIG_TARGET_CORE=m
+CONFIG_TCM_IBLOCK=m
+CONFIG_TCM_FILEIO=m
+CONFIG_TCM_PSCSI=m
+CONFIG_TCM_USER2=m
+# CONFIG_LOOPBACK_TARGET is not set
+CONFIG_ISCSI_TARGET=m
+# CONFIG_XEN_SCSI_BACKEND is not set
+CONFIG_9P_FS=m
+CONFIG_9P_FSCACHE=y
+CONFIG_9P_FS_POSIX_ACL=y
+CONFIG_9P_FS_SECURITY=y
+CONFIG_XXHASH=y
Because CONFIG_KSM changes statically linked code, it results in a size
increase of roughly 12 kB of the compressed kernel. The uncompressed
kernel increases by about 852 kB in size. The boot time appears to be
unchanged. I don't like the size increase, but this feature is enabled
everywhere else and apparently does break some users if it's disabled,
so we should enable it.
The kernel package installed size increases by roughly 2 MB due to the
additional modules we generate for 9P and VHOST_SCSI.
So, I think the answer for these specific requests can be affirmative.
The cost is small enough that if these features are useful to somebody,
then we might as well enable them.
noah
Reply to: