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path: root/kernel/locking/rwsem-spinlock.c
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2016-04-13locking/rwsem: Introduce basis for down_write_killable()Michal Hocko
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>
2016-04-13locking/rwsem: Get rid of __down_write_nested()Michal Hocko
This is no longer used anywhere and all callers (__down_write()) use 0 as a subclass. Ditch __down_write_nested() to make the code easier to follow. This shouldn't introduce any functional change. Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Davidlohr Bueso <dave@stgolabs.net> 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/1460041951-22347-2-git-send-email-mhocko@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-02-18locking/rwsem: Document barrier need when waking tasksDavidlohr Bueso
The need for the smp_mb() in __rwsem_do_wake() should be properly documented. Applies to both xadd and spinlock variants. Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Jason Low <jason.low2@hp.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michel Lespinasse <walken@google.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Link: http://lkml.kernel.org/r/1422609267-15102-3-git-send-email-dave@stgolabs.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-02-04locking/rwsem: Use task->state helpersDavidlohr Bueso
Call __set_task_state() instead of assigning the new state directly. These interfaces also aid CONFIG_DEBUG_ATOMIC_SLEEP environments, keeping track of who last changed the state. Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Jason Low <jason.low2@hp.com> Cc: Michel Lespinasse <walken@google.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1422257769-14083-2-git-send-email-dave@stgolabs.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-07-16locking/rwsem: Rename 'activity' to 'count'Peter Zijlstra
There are two definitions of struct rw_semaphore, one in linux/rwsem.h and one in linux/rwsem-spinlock.h. For some reason they have different names for the initial field. This makes it impossible to use C99 named initialization for __RWSEM_INITIALIZER() -- or we have to duplicate that entire thing along with the structure definitions. The simpler patch is renaming the rwsem-spinlock variant to match the regular rwsem. This allows us to switch to C99 named initialization. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-bmrZolsbGmautmzrerog27io@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-06locking: Move the rwsem code to kernel/locking/Peter Zijlstra
Notably: changed lib/rwsem* targets from lib- to obj-, no idea about the ramifications of that. Suggested-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/n/tip-g0kynfh5feriwc6p3h6kpbw6@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>