Bug#616401: linux-image-2.6.38-rc6-amd64: Please enable FTRACE_SYSCALLS

[Josh Triplett <josh@joshtriplett.org>]

On Sat, Mar 12, 2011 at 10:45:58PM +0000, Ben Hutchings wrote:
> On Thu, 2011-03-03 at 20:34 -0800, Josh Triplett wrote:
> > Package: linux-2.6
> > Version: 2.6.38~rc6-1~experimental.1
> > Severity: wishlist
> > 
> > ~$ perf list | grep syscalls:
> >   raw_syscalls:sys_enter                     [Tracepoint event]
> >   raw_syscalls:sys_exit                      [Tracepoint event]
> > 
> > Please consider enabling CONFIG_FTRACE_SYSCALLS, so perf can trace all
> > syscalls by name and decode them.
> 
> This adds about 100K to the size of the kernel.  I question whether this
> is worth the cost.  Maybe for 64-bit architectures/flavours only?

I don't see anywhere near that amount of overhead.  I just checked, and
with current git master at least, CONFIG_FTRACE_SYSCALLS adds 30240
bytes to the size of bzImage.

I'd certainly consider that worth the benefit of having more of the
functionality of perf work out of the box.

- Josh Triplett