summaryrefslogtreecommitdiff
path: root/include/linux/rwsem.h
diff options
context:
space:
mode:
authorMichal Hocko <mhocko@suse.com>2016-04-07 18:12:26 +0300
committerIngo Molnar <mingo@kernel.org>2016-04-13 11:42:20 +0300
commitd47996082f52baa0ca8b48d26b3cbef5ede70a73 (patch)
tree4cf040a0e47c09d28c974ab775613f461650e1f8 /include/linux/rwsem.h
parent938072e32ce13e5537ef001cdabcb8a6932b09a0 (diff)
downloadlinux-d47996082f52baa0ca8b48d26b3cbef5ede70a73.tar.xz
locking/rwsem: Introduce basis for down_write_killable()
Introduce a generic implementation necessary for down_write_killable(). This is a trivial extension of the already existing down_write() call which can be interrupted by SIGKILL. This patch doesn't provide down_write_killable() yet because arches have to provide the necessary pieces before. rwsem_down_write_failed() which is a generic slow path for the write lock is extended to take a task state and renamed to __rwsem_down_write_failed_common(). The return value is either a valid semaphore pointer or ERR_PTR(-EINTR). rwsem_down_write_failed_killable() is exported as a new way to wait for the lock and be killable. For rwsem-spinlock implementation the current __down_write() it updated in a similar way as __rwsem_down_write_failed_common() except it doesn't need new exports just visible __down_write_killable(). Architectures which are not using the generic rwsem implementation are supposed to provide their __down_write_killable() implementation and use rwsem_down_write_failed_killable() for the slow path. Signed-off-by: Michal Hocko <mhocko@suse.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Chris Zankel <chris@zankel.net> Cc: David S. Miller <davem@davemloft.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Cc: Signed-off-by: Jason Low <jason.low2@hp.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: linux-alpha@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: linux-ia64@vger.kernel.org Cc: linux-s390@vger.kernel.org Cc: linux-sh@vger.kernel.org Cc: linux-xtensa@linux-xtensa.org Cc: sparclinux@vger.kernel.org Link: http://lkml.kernel.org/r/1460041951-22347-7-git-send-email-mhocko@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'include/linux/rwsem.h')
-rw-r--r--include/linux/rwsem.h2
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/rwsem.h b/include/linux/rwsem.h
index 8f498cdde280..7d7ae029dac5 100644
--- a/include/linux/rwsem.h
+++ b/include/linux/rwsem.h
@@ -14,6 +14,7 @@
#include <linux/list.h>
#include <linux/spinlock.h>
#include <linux/atomic.h>
+#include <linux/err.h>
#ifdef CONFIG_RWSEM_SPIN_ON_OWNER
#include <linux/osq_lock.h>
#endif
@@ -43,6 +44,7 @@ struct rw_semaphore {
extern struct rw_semaphore *rwsem_down_read_failed(struct rw_semaphore *sem);
extern struct rw_semaphore *rwsem_down_write_failed(struct rw_semaphore *sem);
+extern struct rw_semaphore *rwsem_down_write_failed_killable(struct rw_semaphore *sem);
extern struct rw_semaphore *rwsem_wake(struct rw_semaphore *);
extern struct rw_semaphore *rwsem_downgrade_wake(struct rw_semaphore *sem);