On 04/02/2019 22.53, Dave Chinner wrote: > On Mon, Feb 04, 2019 at 10:20:35PM +0100, Rasmus Villemoes wrote: >> linux/tracepoints.h allows individual subsystems to disable their >> tracepoints. Add such a knob for xfs. Disabling XFS_TRACEPOINTS >> reduces the resident size of xfs.ko by about a third, or ~350 KiB. > > Ok, now we can't debug typical problems on live production systems > if tracepoints are turned off on the user/distro kernels. So under > what circumstances would we ever want to turn off tracepoints on > XFS? I don't expect any mainstream distros to turn it off. But for embedded systems that use a hand-tuned .config, being able to shave off 100s of K of the kernel image is quite valuable. Tracing _is_ useful, also/especially when doing embedded development, which is why "just turn off CONFIG_TRACING" isn't really an option. Would the knob be more acceptable if it was under CONFIG_EXPERT? Rasmus
