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author | Kirill Tkhai <ktkhai@virtuozzo.com> | 2017-06-19 21:02:26 +0300 |
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committer | Ingo Molnar <mingo@kernel.org> | 2017-08-10 12:28:55 +0200 |
commit | 83ced169d9a01f22eb39f1fcc1f89ad9d223238f (patch) | |
tree | bd17aff54d304333ad9441a0a494cf0201de6a72 /include/linux/rwsem.h | |
parent | 0aa1125fa8bc5e5f98317156728fa4d0293561a5 (diff) | |
download | lwn-83ced169d9a01f22eb39f1fcc1f89ad9d223238f.tar.gz lwn-83ced169d9a01f22eb39f1fcc1f89ad9d223238f.zip |
locking/rwsem-xadd: Add killable versions of rwsem_down_read_failed()
Rename rwsem_down_read_failed() in __rwsem_down_read_failed_common()
and teach it to abort waiting in case of pending signals and killable
state argument passed.
Note, that we shouldn't wake anybody up in EINTR path, as:
We check for (waiter.task) under spinlock before we go to out_nolock
path. Current task wasn't able to be woken up, so there are
a writer, owning the sem, or a writer, which is the first waiter.
In the both cases we shouldn't wake anybody. If there is a writer,
owning the sem, and we were the only waiter, remove RWSEM_WAITING_BIAS,
as there are no waiters anymore.
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: arnd@arndb.de
Cc: avagin@virtuozzo.com
Cc: davem@davemloft.net
Cc: fenghua.yu@intel.com
Cc: gorcunov@virtuozzo.com
Cc: heiko.carstens@de.ibm.com
Cc: hpa@zytor.com
Cc: ink@jurassic.park.msu.ru
Cc: mattst88@gmail.com
Cc: rth@twiddle.net
Cc: schwidefsky@de.ibm.com
Cc: tony.luck@intel.com
Link: http://lkml.kernel.org/r/149789534632.9059.2901382369609922565.stgit@localhost.localdomain
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'include/linux/rwsem.h')
-rw-r--r-- | include/linux/rwsem.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/rwsem.h b/include/linux/rwsem.h index dd1d14250340..0ad7318ff299 100644 --- a/include/linux/rwsem.h +++ b/include/linux/rwsem.h @@ -44,6 +44,7 @@ struct rw_semaphore { }; extern struct rw_semaphore *rwsem_down_read_failed(struct rw_semaphore *sem); +extern struct rw_semaphore *rwsem_down_read_failed_killable(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 *); |