diff options
| author | Kumar Kartikeya Dwivedi <memxor@gmail.com> | 2025-03-16 07:05:30 +0300 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2025-03-19 18:03:05 +0300 |
| commit | ecbd8047526d3e9681043c287dea7bc67ef33eb4 (patch) | |
| tree | e43a42794fc1b248f2040e43b0aa93da7175a270 /include/asm-generic | |
| parent | c9102a68c070134ade5c941d7315481a77bcea53 (diff) | |
| download | linux-ecbd8047526d3e9681043c287dea7bc67ef33eb4.tar.xz | |
rqspinlock: Add basic support for CONFIG_PARAVIRT
We ripped out PV and virtualization related bits from rqspinlock in an
earlier commit, however, a fair lock performs poorly within a virtual
machine when the lock holder is preempted. As such, retain the
virt_spin_lock fallback to test and set lock, but with timeout and
deadlock detection. We can do this by simply depending on the
resilient_tas_spin_lock implementation from the previous patch.
We don't integrate support for CONFIG_PARAVIRT_SPINLOCKS yet, as that
requires more involved algorithmic changes and introduces more
complexity. It can be done when the need arises in the future.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250316040541.108729-15-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'include/asm-generic')
| -rw-r--r-- | include/asm-generic/rqspinlock.h | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/include/asm-generic/rqspinlock.h b/include/asm-generic/rqspinlock.h index 12f72c4a97cd..a837c6b6abd9 100644 --- a/include/asm-generic/rqspinlock.h +++ b/include/asm-generic/rqspinlock.h @@ -35,6 +35,20 @@ extern int resilient_tas_spin_lock(rqspinlock_t *lock); extern int resilient_queued_spin_lock_slowpath(rqspinlock_t *lock, u32 val); #endif +#ifndef resilient_virt_spin_lock_enabled +static __always_inline bool resilient_virt_spin_lock_enabled(void) +{ + return false; +} +#endif + +#ifndef resilient_virt_spin_lock +static __always_inline int resilient_virt_spin_lock(rqspinlock_t *lock) +{ + return 0; +} +#endif + /* * Default timeout for waiting loops is 0.25 seconds */ |