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authorNicolas Pitre <nicolas.pitre@linaro.org>2016-11-11 00:10:10 -0500
committerThomas Gleixner <tglx@linutronix.de>2016-11-16 09:26:35 +0100
commitbaa73d9e478ff32d62f3f9422822b59dd9a95a21 (patch)
treeec1ac1b90e4a6c6337acb564d7fb518418fc510f /init
parent53d3eaa31508222e445b489f3c3ac4c63542a4ef (diff)
downloadlinux-baa73d9e478ff32d62f3f9422822b59dd9a95a21.tar.gz
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 <nico@linaro.org> Acked-by: Richard Cochran <richardcochran@gmail.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: John Stultz <john.stultz@linaro.org> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Cc: Paul Bolle <pebolle@tiscali.nl> Cc: linux-kbuild@vger.kernel.org Cc: netdev@vger.kernel.org Cc: Michal Marek <mmarek@suse.com> Cc: Edward Cree <ecree@solarflare.com> Link: http://lkml.kernel.org/r/1478841010-28605-7-git-send-email-nicolas.pitre@linaro.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'init')
-rw-r--r--init/Kconfig17
1 files changed, 17 insertions, 0 deletions
diff --git a/init/Kconfig b/init/Kconfig
index 34407f1..456e0b8 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