From baa73d9e478ff32d62f3f9422822b59dd9a95a21 Mon Sep 17 00:00:00 2001 From: Nicolas Pitre Date: Fri, 11 Nov 2016 00:10:10 -0500 Subject: posix-timers: Make them configurable Some embedded systems have no use for them. This removes about 25KB from the kernel binary size when configured out. Corresponding syscalls are routed to a stub logging the attempt to use those syscalls which should be enough of a clue if they were disabled without proper consideration. They are: timer_create, timer_gettime: timer_getoverrun, timer_settime, timer_delete, clock_adjtime, setitimer, getitimer, alarm. The clock_settime, clock_gettime, clock_getres and clock_nanosleep syscalls are replaced by simple wrappers compatible with CLOCK_REALTIME, CLOCK_MONOTONIC and CLOCK_BOOTTIME only which should cover the vast majority of use cases with very little code. Signed-off-by: Nicolas Pitre Acked-by: Richard Cochran Acked-by: Thomas Gleixner Acked-by: John Stultz Reviewed-by: Josh Triplett Cc: Paul Bolle Cc: linux-kbuild@vger.kernel.org Cc: netdev@vger.kernel.org Cc: Michal Marek Cc: Edward Cree Link: http://lkml.kernel.org/r/1478841010-28605-7-git-send-email-nicolas.pitre@linaro.org Signed-off-by: Thomas Gleixner --- init/Kconfig | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) (limited to 'init') diff --git a/init/Kconfig b/init/Kconfig index 34407f15e6d3..456e0b891238 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1445,6 +1445,23 @@ config SYSCTL_SYSCALL If unsure say N here. +config POSIX_TIMERS + bool "Posix Clocks & timers" if EXPERT + default y + help + This includes native support for POSIX timers to the kernel. + Some embedded systems have no use for them and therefore they + can be configured out to reduce the size of the kernel image. + + When this option is disabled, the following syscalls won't be + available: timer_create, timer_gettime: timer_getoverrun, + timer_settime, timer_delete, clock_adjtime, getitimer, + setitimer, alarm. Furthermore, the clock_settime, clock_gettime, + clock_getres and clock_nanosleep syscalls will be limited to + CLOCK_REALTIME, CLOCK_MONOTONIC and CLOCK_BOOTTIME only. + + If unsure say y. + config KALLSYMS bool "Load all symbols for debugging/ksymoops" if EXPERT default y -- cgit v1.2.3