Messages in this thread | | | From | Waiman Long <> | Subject | [PATCH v6 0/6] lockinig/rwsem: Fix rwsem bugs & enable true lock handoff | Date | Thu, 17 Nov 2022 21:20:10 -0500 |
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v6: - Fix an error in patch 2 reported by kernel test robot.
v5: - Drop patch 2 and replace it with 2 new patches disabling preemption on all reader functions and writer functions respectively. The other patches are adjusted accordingly.
v4: - Update patch descriptions in patches 1 & 2 to make clear the live lock conditions that are being fixed by these patches. There is no code change from v3.
It turns out the current waiter optimistic spinning code does not work that well if we have RT tasks in the mix. This patch series include two different fixes to resolve those issues. The last 3 patches modify the handoff code to implement true lock handoff similar to that of mutex.
Waiman Long (6): locking/rwsem: Prevent non-first waiter from spinning in down_write() slowpath locking/rwsem: Disable preemption at all down_read*() and up_read() code paths locking/rwsem: Disable preemption at all down_write*() and up_write() code paths locking/rwsem: Change waiter->hanodff_set to a handoff_state enum locking/rwsem: Enable direct rwsem lock handoff locking/rwsem: Update handoff lock events tracking
kernel/locking/lock_events_list.h | 6 +- kernel/locking/rwsem.c | 240 ++++++++++++++++++++++-------- 2 files changed, 182 insertions(+), 64 deletions(-)
-- 2.31.1
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