On Mon, Oct 28, 2019 at 08:49:36PM +0530, madhuparnabhowmik04@xxxxxxxxx wrote: > From: Madhuparna Bhowmik <madhuparnabhowmik04@xxxxxxxxx> > > This patch converts arrayRCU from txt to rst format. > arrayRCU.rst is also added in the index.rst file. > > Signed-off-by: Madhuparna Bhowmik <madhuparnbhowmik04@xxxxxxxxx> > Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik04@xxxxxxxxx> Thank you, but this does not apply to the -rcu git repo's "dev" branch. Could you please tell me what commit you developed this against? FYI, the location and much more about -rcu may be found here: https://mirrors.edge.kernel.org/pub/linux/kernel/people/paulmck/rcutodo.html Thanx, Paul > --- > .../RCU/{arrayRCU.txt => arrayRCU.rst} | 18 ++++++++++++++---- > Documentation/RCU/index.rst | 1 + > 2 files changed, 15 insertions(+), 4 deletions(-) > rename Documentation/RCU/{arrayRCU.txt => arrayRCU.rst} (91%) > > diff --git a/Documentation/RCU/arrayRCU.txt b/Documentation/RCU/arrayRCU.rst > similarity index 91% > rename from Documentation/RCU/arrayRCU.txt > rename to Documentation/RCU/arrayRCU.rst > index f05a9afb2c39..c8a26f7b2577 100644 > --- a/Documentation/RCU/arrayRCU.txt > +++ b/Documentation/RCU/arrayRCU.rst > @@ -1,4 +1,7 @@ > +.. _array_rcu_doc: > + > Using RCU to Protect Read-Mostly Arrays > +======================================= > > > Although RCU is more commonly used to protect linked lists, it can > @@ -26,6 +29,7 @@ described in the following sections. > > > Situation 1: Hash Tables > +------------------------ > > Hash tables are often implemented as an array, where each array entry > has a linked-list hash chain. Each hash chain can be protected by RCU > @@ -34,6 +38,7 @@ to other array-of-list situations, such as radix trees. > > > Situation 2: Static Arrays > +-------------------------- > > Static arrays, where the data (rather than a pointer to the data) is > located in each array element, and where the array is never resized, > @@ -41,11 +46,14 @@ have not been used with RCU. Rik van Riel recommends using seqlock in > this situation, which would also have minimal read-side overhead as long > as updates are rare. > > -Quick Quiz: Why is it so important that updates be rare when > - using seqlock? > +Quick Quiz: > + Why is it so important that updates be rare when using seqlock? > + > +:ref:`Answer to Quick Quiz <answer_quick_quiz_seqlock>` > > > Situation 3: Resizeable Arrays > +------------------------------ > > Use of RCU for resizeable arrays is demonstrated by the grow_ary() > function formerly used by the System V IPC code. The array is used > @@ -60,7 +68,7 @@ the remainder of the new, updates the ids->entries pointer to point to > the new array, and invokes ipc_rcu_putref() to free up the old array. > Note that rcu_assign_pointer() is used to update the ids->entries pointer, > which includes any memory barriers required on whatever architecture > -you are running on. > +you are running on.:: > > static int grow_ary(struct ipc_ids* ids, int newsize) > { > @@ -112,7 +120,7 @@ a simple check suffices. The pointer to the structure corresponding > to the desired IPC object is placed in "out", with NULL indicating > a non-existent entry. After acquiring "out->lock", the "out->deleted" > flag indicates whether the IPC object is in the process of being > -deleted, and, if not, the pointer is returned. > +deleted, and, if not, the pointer is returned.:: > > struct kern_ipc_perm* ipc_lock(struct ipc_ids* ids, int id) > { > @@ -144,8 +152,10 @@ deleted, and, if not, the pointer is returned. > return out; > } > > +.. _answer_quick_quiz_seqlock: > > Answer to Quick Quiz: > + Why is it so important that updates be rare when using seqlock? > > The reason that it is important that updates be rare when > using seqlock is that frequent updates can livelock readers. > diff --git a/Documentation/RCU/index.rst b/Documentation/RCU/index.rst > index 340a9725676c..c4586602e7e2 100644 > --- a/Documentation/RCU/index.rst > +++ b/Documentation/RCU/index.rst > @@ -7,6 +7,7 @@ RCU concepts > .. toctree:: > :maxdepth: 1 > > + arrayRCU > rcu > listRCU > UP > -- > 2.17.1 >
