percpu_rw_semaphore: introduce CONFIG_PERCPU_RWSEM

Currently only block_dev and uprobes use percpu_rw_semaphore,
add the config option selected by BLOCK || UPROBES.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Anton Arapov <anton@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/arch/Kconfig b/arch/Kconfig
index 34884faf98cd..54ffd0f9df21 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -80,6 +80,7 @@ config UPROBES
         bool "Transparent user-space probes (EXPERIMENTAL)"
         depends on UPROBE_EVENT && PERF_EVENTS
         default n
+        select PERCPU_RWSEM
         help
           Uprobes is the user-space counterpart to kprobes: they
           enable instrumentation applications (such as 'perf probe')