Nicholas Piggin wrote:
Naveen N. Rao's on May 18, 2019 5:02 am:
With -mprofile-kernel, gcc emits 'mflr r0', followed by 'bl _mcount' to
enable function tracing and profiling. So far, with dynamic ftrace, we
used to only patch out the branch to _mcount(). However, Nick Piggin
points out that "mfl
Naveen N. Rao's on May 18, 2019 5:02 am:
> With -mprofile-kernel, gcc emits 'mflr r0', followed by 'bl _mcount' to
> enable function tracing and profiling. So far, with dynamic ftrace, we
> used to only patch out the branch to _mcount(). However, Nick Piggin
> points out that "mflr is executed by t
With -mprofile-kernel, gcc emits 'mflr r0', followed by 'bl _mcount' to
enable function tracing and profiling. So far, with dynamic ftrace, we
used to only patch out the branch to _mcount(). However, Nick Piggin
points out that "mflr is executed by the branch unit that can only
execute one per cycl