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author | Ingo Molnar <mingo@kernel.org> | 2019-10-31 09:33:19 +0100 |
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committer | Ingo Molnar <mingo@kernel.org> | 2019-10-31 09:33:19 +0100 |
commit | 43e0ae7ae0f567a3f8c10ec7a4078bc482660921 (patch) | |
tree | f44975fcd01ee1a6c5f519bf0456e1547a5e3752 /include/linux/rcupdate.h | |
parent | Merge tag 'iommu-fixes-v5.4-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu (diff) | |
parent | Merge branches 'doc.2019.10.29a', 'fixes.2019.10.30a', 'nohz.2019.10.28a', 'replace.2019.10.30a', 'torture.2019.10.05a' and 'lkmm.2019.10.05a' into HEAD (diff) | |
download | linux-dev-43e0ae7ae0f567a3f8c10ec7a4078bc482660921.tar.xz linux-dev-43e0ae7ae0f567a3f8c10ec7a4078bc482660921.zip |
Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu
Pull RCU and LKMM changes from Paul E. McKenney:
- Documentation updates.
- Miscellaneous fixes.
- Dynamic tick (nohz) updates, perhaps most notably changes to
force the tick on when needed due to lengthy in-kernel execution
on CPUs on which RCU is waiting.
- Replace rcu_swap_protected() with rcu_prepace_pointer().
- Torture-test updates.
- Linux-kernel memory consistency model updates.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'include/linux/rcupdate.h')
-rw-r--r-- | include/linux/rcupdate.h | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index 75a2eded7aa2..185dd9736863 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -383,6 +383,24 @@ do { \ } while (0) /** + * rcu_replace_pointer() - replace an RCU pointer, returning its old value + * @rcu_ptr: RCU pointer, whose old value is returned + * @ptr: regular pointer + * @c: the lockdep conditions under which the dereference will take place + * + * Perform a replacement, where @rcu_ptr is an RCU-annotated + * pointer and @c is the lockdep argument that is passed to the + * rcu_dereference_protected() call used to read that pointer. The old + * value of @rcu_ptr is returned, and @rcu_ptr is set to @ptr. + */ +#define rcu_replace_pointer(rcu_ptr, ptr, c) \ +({ \ + typeof(ptr) __tmp = rcu_dereference_protected((rcu_ptr), (c)); \ + rcu_assign_pointer((rcu_ptr), (ptr)); \ + __tmp; \ +}) + +/** * rcu_swap_protected() - swap an RCU and a regular pointer * @rcu_ptr: RCU pointer * @ptr: regular pointer |