svn commit: r344487 - in head/sys: conf gnu/gcov

[Alan Somers]

On Thu, Feb 28, 2019 at 6:40 PM Matthew Macy <mmacy at freebsd.org> wrote:
>
> to config add:
> options LINDEBUGFS
> options GCOV
>
> compile kernel with gcc (otherwise it will be a no-op)
>
> sysctl debug.gcov.enable=1
>
> mount -t debugfs debugfs /sys/kernel/debug
>
> (or wherever) and the output artifacts will appear under gcov/<kernel
> build path> - you need to be root to see the artifacts
>
> gcov can then generate the results as it would normally from the
> profiling and the build time artifacts
>
> bug reports welcome
>
>
> -M

Here's a bug report: I rebuilt the kernel but boot fails with this
error.  Do I need to rebuild world too?

Mounting local filesystems:kldload: fdescfs.ko: lost base for reltab
linker_load_file: /boot/kernel/fdescfs.ko - unsupported file type
mount: fdescfs: Operation not supported by device
Mounting /etc/fstab filesystems failed, will retry after root mount hold release
kldload: fdescfs.ko: lost base for reltab
linker_load_file: /boot/kernel/fdescfs.ko - unsupported file type
mount: fdescfs: Operation not supported by device
.
Mounting /etc/fstab filesystems failed, startup aborted