diff options
| author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2017-05-13 01:56:35 +0300 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2017-06-09 04:52:41 +0300 |
| commit | 41a2901e7d220875752a8c870e0b53288a578c20 (patch) | |
| tree | 7fee0c0fb4e4de059050c0003c370042bb832ffc /Documentation/RCU | |
| parent | c4a09ff752e164c020bced6513e2008f992a02e6 (diff) | |
| download | linux-41a2901e7d220875752a8c870e0b53288a578c20.tar.xz | |
rcu: Remove SPARSE_RCU_POINTER Kconfig option
The sparse-based checking for non-RCU accesses to RCU-protected pointers
has been around for a very long time, and it is now the only type of
sparse-based checking that is optional. This commit therefore makes
it unconditional.
Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Diffstat (limited to 'Documentation/RCU')
| -rw-r--r-- | Documentation/RCU/Design/Requirements/Requirements.html | 9 | ||||
| -rw-r--r-- | Documentation/RCU/checklist.txt | 8 |
2 files changed, 7 insertions, 10 deletions
diff --git a/Documentation/RCU/Design/Requirements/Requirements.html b/Documentation/RCU/Design/Requirements/Requirements.html index 8c94fc1d1c84..0e6550a8c926 100644 --- a/Documentation/RCU/Design/Requirements/Requirements.html +++ b/Documentation/RCU/Design/Requirements/Requirements.html @@ -559,9 +559,7 @@ The <tt>rcu_access_pointer()</tt> on line 6 is similar to For <tt>remove_gp_synchronous()</tt>, as long as all modifications to <tt>gp</tt> are carried out while holding <tt>gp_lock</tt>, the above optimizations are harmless. - However, - with <tt>CONFIG_SPARSE_RCU_POINTER=y</tt>, - <tt>sparse</tt> will complain if you + However, <tt>sparse</tt> will complain if you define <tt>gp</tt> with <tt>__rcu</tt> and then access it without using either <tt>rcu_access_pointer()</tt> or <tt>rcu_dereference()</tt>. @@ -1978,9 +1976,8 @@ guard against mishaps and misuse: and <tt>rcu_dereference()</tt>, perhaps (incorrectly) substituting a simple assignment. To catch this sort of error, a given RCU-protected pointer may be - tagged with <tt>__rcu</tt>, after which running sparse - with <tt>CONFIG_SPARSE_RCU_POINTER=y</tt> will complain - about simple-assignment accesses to that pointer. + tagged with <tt>__rcu</tt>, after which sparse + will complain about simple-assignment accesses to that pointer. Arnd Bergmann made me aware of this requirement, and also supplied the needed <a href="https://lwn.net/Articles/376011/">patch series</a>. diff --git a/Documentation/RCU/checklist.txt b/Documentation/RCU/checklist.txt index 877947130ebe..6beda556faf3 100644 --- a/Documentation/RCU/checklist.txt +++ b/Documentation/RCU/checklist.txt @@ -413,11 +413,11 @@ over a rather long period of time, but improvements are always welcome! read-side critical sections. It is the responsibility of the RCU update-side primitives to deal with this. -17. Use CONFIG_PROVE_RCU, CONFIG_DEBUG_OBJECTS_RCU_HEAD, and the - __rcu sparse checks (enabled by CONFIG_SPARSE_RCU_POINTER) to - validate your RCU code. These can help find problems as follows: +17. Use CONFIG_PROVE_LOCKING, CONFIG_DEBUG_OBJECTS_RCU_HEAD, and the + __rcu sparse checks to validate your RCU code. These can help + find problems as follows: - CONFIG_PROVE_RCU: check that accesses to RCU-protected data + CONFIG_PROVE_LOCKING: check that accesses to RCU-protected data structures are carried out under the proper RCU read-side critical section, while holding the right combination of locks, or whatever other conditions |