Test the basic functionality for the NUMA and MPOL flags:
- FUTEX2_NUMA should take the NUMA node which is after the uaddr
and use it.
- Only update the node if FUTEX_NO_NODE was set by the user
- FUTEX2_MPOL should use the memory based on the policy. I attempted to
set the node with mbind() and then use this with MPOL but this fails
and futex falls back to the default node for the current CPU.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250416162921.513656-22-bigeasy@linutronix.de
Test the basic functionality of the private hash:
- Upon start, with no threads there is no private hash.
- The first thread initializes the private hash.
- More than four threads will increase the size of the private hash if
the system has more than 16 CPUs online.
- Once the user sets the size of private hash, auto scaling is disabled.
- The user is only allowed to use numbers to the power of two.
- The user may request the global or make the hash immutable.
- Once the global hash has been set or the hash has been made immutable,
further changes are not allowed.
- Futex operations should work the whole time. It must be possible to
hold a lock, such a PI initialised mutex, during the resize operation.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250416162921.513656-21-bigeasy@linutronix.de
There are three different strategies to uniquely identify a futex in the
kernel:
- Private futexes: uses the pointer to mm_struct and the page address
- Shared futexes: checks if the page containing the address is a PageAnon:
- If it is, uses the same data as a private futexes
- If it isn't, uses an inode sequence number from struct inode and
the page's index
Create a selftest to check those three paths and basic wait/wake
mechanism.
Signed-off-by: André Almeida <andrealmeid@collabora.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Davidlohr Bueso <dbueso@suse.de>
Link: https://lore.kernel.org/r/20210531165036.41468-2-andrealmeid@collabora.com
