linux.git/tools/testing/selftests/futex/functional/futex_wait.c, branch vsnprintf Linux kernel source tree selftests: futex: Add futex wait test 2021-06-22T09:20:15+00:00 André Almeida andrealmeid@collabora.com 2021-05-31T16:50:35+00:00 c3d128581f64a9b3729e697a63760ff0a2c4a8fe 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 
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