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

[Matthew Macy]

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














On Thu, Feb 28, 2019 at 2:50 PM Alan Somers <asomers at freebsd.org> wrote:
>
> On Sat, Feb 23, 2019 at 2:14 PM Matt Macy <mmacy at freebsd.org> wrote:
> >
> > Author: mmacy
> > Date: Sat Feb 23 21:14:00 2019
> > New Revision: 344487
> > URL: https://svnweb.freebsd.org/changeset/base/344487
> >
> > Log:
> >   gcov support
> >
> >   add gcov support and export results as files in debugfs
> >
> >   Reviewed by:  hps@
> >   MFC after:    1 week
> >   Sponsored by: iX Systems
> >   Differential Revision:        https://reviews.freebsd.org/D19260
> >
> > Added:
> >   head/sys/gnu/gcov/
> >   head/sys/gnu/gcov/gcc_4_7.c   (contents, props changed)
> >   head/sys/gnu/gcov/gcov.h   (contents, props changed)
> >   head/sys/gnu/gcov/gcov_fs.c   (contents, props changed)
> >   head/sys/gnu/gcov/gcov_subr.c   (contents, props changed)
> > Modified:
> >   head/sys/conf/files
> >   head/sys/conf/kern.mk
> >   head/sys/conf/kern.post.mk
> >   head/sys/conf/kern.pre.mk
> >   head/sys/conf/kmod.mk
> >   head/sys/conf/options
>
> On a more practical note, how does one use this new feature?  It looks
> like it could be quite useful.
> -Alan