Author: Michael Jeanson
Author Date: 2023-10-03 18:59:08 UTC

fix: add missing SPDX licensing tags

Change-Id: If7016a3c83211e88c102f8b395dc290859af4789
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Author: Olivier Dion
Author Date: 2023-09-28 16:53:46 UTC

urcu/uatomic/riscv: Mark RISC-V as broken

Implementations of some atomic operations of GCC for RISC-V are
insufficient for sequential consistency. For this reason Userspace RCU
is currently marked as `broken' for RISC-V with GCC. However, it is
still possible to use other toolchains.

See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104831 for details.

For now, we mark every version of GCC as unsupported. Distribution
package maintainers will have to cherry-pick the relevant patches in GCC
then remove the #error in Userspace RCU if they want to support it.

As for us, we will incrementally add specific versions of GCC that have
fixed the issue whenever new stable releases are made from the GCC
project.

Change-Id: I2cd7c8f12068628b845a096e03f5f8100eacbe43
Signed-off-by: Olivier Dion <odion@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Author: Olivier Dion
Author Date: 2023-09-28 16:53:46 UTC

urcu/uatomic/riscv: Mark RISC-V as broken

Implementations of some atomic operations of GCC for RISC-V are
insufficient for sequential consistency. For this reason Userspace RCU
is currently marked as `broken' for RISC-V with GCC. However, it is
still possible to use other toolchains.

See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104831 for details.

For now, we mark every version of GCC as unsupported. Distribution
package maintainers will have to cherry-pick the relevant patches in GCC
then remove the #error in Userspace RCU if they want to support it.

As for us, we will incrementally add specific versions of GCC that have
fixed the issue whenever new stable releases are made from the GCC
project.

Change-Id: I2cd7c8f12068628b845a096e03f5f8100eacbe43
Signed-off-by: Olivier Dion <odion@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Author: Mathieu Desnoyers
Author Date: 2023-02-14 15:49:33 UTC

Version 0.12.5

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: Iab87437032adbac6ce1ad0e0de2f47f2caf2e4f9

Author: Mathieu Desnoyers
Author Date: 2016-08-24 20:02:02 UTC

RCU Judy Array (rcuja) implementation

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Author: Mathieu Desnoyers
Author Date: 2022-01-05 20:06:19 UTC

Version 0.11.4

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: Ia6c8ec40b503ce8c1bbcc378fcea19085f4683b4

Author: Mathieu Desnoyers
Author Date: 2020-04-22 12:55:50 UTC

Version 0.9.7

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Author: Mathieu Desnoyers
Author Date: 2020-04-22 12:53:57 UTC

Version 0.10.3

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Author: Mathieu Desnoyers
Author Date: 2018-01-23 20:16:37 UTC

Version 0.8.11

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Author: Mathieu Desnoyers
Author Date: 2016-04-26 21:04:56 UTC

Version 0.7.17

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Author: Mathieu Desnoyers
Author Date: 2015-05-04 17:38:34 UTC

Fix: rcuja merge fixes

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Author: Mathieu Desnoyers
Author Date: 2014-11-13 21:17:00 UTC

Fix: call rcu should call internal RCU API

Because call rcu implementation is included within RCU flavors, calling
the RCU API goes through the API for non-LGPL code (this is a special
case for the RCU flavor implementation c file). Since this is clearly
LGPL code, we can use the inline versions.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Author: Mathieu Desnoyers
Author Date: 2014-11-13 21:14:36 UTC

Fix: memory leak in urcu-checker

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Author: Mathieu Desnoyers
Author Date: 2014-10-24 11:26:55 UTC

waitqueue: add in_waitqueue field

Using the waitqueue node next pointer to figure out if the node is
within the queue worked when wfstack was used to implement the queue
stack, but unfortunately it does not keep the same semantic with
lfstack: indeed, the bottom of stack is indicated by a NULL pointer too.

Keep this state in a separate field instead to eliminate coupling
between workqueue, waitqueue and lfstack.

Note that it is OK for a worker to see "in_waitqueue" as temporarily
false when the wait node has just been pop'd from the waitqueue. It's
the opposite that we never want to happen: a worker should never see
"in_waitqueue" as false when the node is actually in the waitqueue,
because it would cause queue corruption.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Author: Mathieu Desnoyers
Author Date: 2013-11-11 21:50:15 UTC

Test fix: 0.6 branch does not have tls-compat.h

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Author: Mathieu Desnoyers
Author Date: 2013-08-25 18:22:15 UTC

Implement DQ unit test

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Author: Mathieu Desnoyers
Author Date: 2013-06-07 21:29:39 UTC

rcuja: cleanup

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Author: Mathieu Desnoyers
Author Date: 2012-10-09 04:12:47 UTC

Revert "spinlock model: Simplify state-space"

This reverts commit a9227ee907160443d0e4b1639b274ab9278d92fa.

Need to study impact on progress.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Author: Mathieu Desnoyers
Author Date: 2012-02-22 00:06:52 UTC

RCU lock-free hash table: implement cds_lfht_is_node_deleted()

Some thoughts on how to use the RCU lock-free hash table brought me to
figure out that using the lock-free hash table along with a per-node
mutex is a quite interesting way to deal with lookup vs teardown
coherency.

A per-node lock can be used to protect concurrent modifications of an
entry from one another, as well as concurrent read vs modification. In
addition, if we ensure that each reader/updater of the node checks if
the node has been removed right after taking the mutex, and if we
perform the node removal from the hash table with the per-node mutex
held, we can ensure that readers/updaters will never access unlinked
data.

struct mynode {
 pthread_mutex_t mutex;
 struct cds_lfht node;
}

CPU A (lookup destroy and free) CPU B (lookup and read/modify)

                                          rcu_read_lock()
                                          mynode = caa_container_of(
                                                cds_lfht_lookup(...), ...);
                                          mutex_lock(&mynode->mutex);
                                          if (cds_lfht_is_node_deleted(
       &mynode->node))
                                               goto unlock;

                                          read/modify structure....

                                        unlock:
                                          mutex_unlock(&mynode->mutex);
                                          rcu_read_unlock()

rcu_read_lock()
mynode = caa_container_of(
        cds_lfht_lookup(...), ...);

mutex_lock(&mynode->mutex);

cds_lfht_del(ht, &mynode->node);

- perform extra teardown operations
  with side-effects, for which call_rcu
  delay is not appropriate

mutex_unlock(&mynode->mutex);
rcu_read_unlock()
call_rcu(free, mynode);

To perform this efficiently, we need an API function to return whether
the node previously looked-up has been deleted since then.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
CC: Lai Jiangshan <laijs@cn.fujitsu.com>
CC: Stephen Hemminger <shemminger@vyatta.com>

Author: Mathieu Desnoyers
Author Date: 2011-09-19 17:27:08 UTC

rculfhash: add TODO for resize worker threads

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Author: Mathieu Desnoyers
Author Date: 2011-09-11 06:40:29 UTC

rbtree test: add missing call_rcu per-cpu threads teardown

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Author: Mathieu Desnoyers
Author Date: 2011-09-05 11:15:30 UTC

Add no locking test option for glib hash

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Author: Mathieu Desnoyers
Author Date: 2011-09-05 00:30:27 UTC

add test_lfs_baseline

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Author: Mathieu Desnoyers
Author Date: 2011-09-05 00:27:56 UTC

Fix typo in makefile

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Author: Mathieu Desnoyers
Author Date: 2011-09-03 20:23:24 UTC

rculfhash test: Check random pool size

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Author: Mathieu Desnoyers
Author Date: 2011-08-17 10:07:44 UTC

Merge branch 'lfqueue-dev' into lfqueue-dev2

Author: Mathieu Desnoyers
Author Date: 2011-08-17 10:07:35 UTC

Merge branch 'master' into lfqueue-dev

Author: Mathieu Desnoyers
Author Date: 2010-03-22 19:09:44 UTC

rbtree test: show tree

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Author: Mathieu Desnoyers
Author Date: 2010-03-01 20:15:19 UTC

LFQ: Fix unpaired lock/unlock

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Author: Mathieu Desnoyers
Author Date: 2009-09-26 22:29:37 UTC

qsbr: only mark reader thread as being waited for in contended case

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>

Author: Mathieu Desnoyers
Author Date: 2009-09-26 22:29:37 UTC

qsbr: only mark reader thread as being waited for in contended case

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>

Author: Mathieu Desnoyers
Author Date: 2009-09-26 12:19:26 UTC

Add multiple reader queues to futex model

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>

Author: Mathieu Desnoyers
Author Date: 2009-09-24 00:55:52 UTC

urcu-defer: fix futex wakeup value

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>