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authorLinus Torvalds <torvalds@linux-foundation.org>2020-03-31 02:17:15 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2020-03-31 02:17:15 +0300
commit4b9fd8a829a1eec7442e38afff21d610604de56a (patch)
tree32757737b7eecbe8c5be7606d8dcec883d39f1e6 /lib
parenta776c270a0b2fad6715cb714187e4290cadb9237 (diff)
parentf1e67e355c2aafeddf1eac31335709236996d2fe (diff)
downloadlinux-4b9fd8a829a1eec7442e38afff21d610604de56a.tar.xz
Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking updates from Ingo Molnar: "The main changes in this cycle were: - Continued user-access cleanups in the futex code. - percpu-rwsem rewrite that uses its own waitqueue and atomic_t instead of an embedded rwsem. This addresses a couple of weaknesses, but the primary motivation was complications on the -rt kernel. - Introduce raw lock nesting detection on lockdep (CONFIG_PROVE_RAW_LOCK_NESTING=y), document the raw_lock vs. normal lock differences. This too originates from -rt. - Reuse lockdep zapped chain_hlocks entries, to conserve RAM footprint on distro-ish kernels running into the "BUG: MAX_LOCKDEP_CHAIN_HLOCKS too low!" depletion of the lockdep chain-entries pool. - Misc cleanups, smaller fixes and enhancements - see the changelog for details" * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (55 commits) fs/buffer: Make BH_Uptodate_Lock bit_spin_lock a regular spinlock_t thermal/x86_pkg_temp: Make pkg_temp_lock a raw_spinlock_t Documentation/locking/locktypes: Minor copy editor fixes Documentation/locking/locktypes: Further clarifications and wordsmithing m68knommu: Remove mm.h include from uaccess_no.h x86: get rid of user_atomic_cmpxchg_inatomic() generic arch_futex_atomic_op_inuser() doesn't need access_ok() x86: don't reload after cmpxchg in unsafe_atomic_op2() loop x86: convert arch_futex_atomic_op_inuser() to user_access_begin/user_access_end() objtool: whitelist __sanitizer_cov_trace_switch() [parisc, s390, sparc64] no need for access_ok() in futex handling sh: no need of access_ok() in arch_futex_atomic_op_inuser() futex: arch_futex_atomic_op_inuser() calling conventions change completion: Use lockdep_assert_RT_in_threaded_ctx() in complete_all() lockdep: Add posixtimer context tracing bits lockdep: Annotate irq_work lockdep: Add hrtimer context tracing bits lockdep: Introduce wait-type checks completion: Use simple wait queues sched/swait: Prepare usage in completions ...
Diffstat (limited to 'lib')
-rw-r--r--lib/Kconfig.debug17
1 files changed, 17 insertions, 0 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 69def4a9df00..70813e39f911 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1086,6 +1086,23 @@ config PROVE_LOCKING
For more details, see Documentation/locking/lockdep-design.rst.
+config PROVE_RAW_LOCK_NESTING
+ bool "Enable raw_spinlock - spinlock nesting checks"
+ depends on PROVE_LOCKING
+ default n
+ help
+ Enable the raw_spinlock vs. spinlock nesting checks which ensure
+ that the lock nesting rules for PREEMPT_RT enabled kernels are
+ not violated.
+
+ NOTE: There are known nesting problems. So if you enable this
+ option expect lockdep splats until these problems have been fully
+ addressed which is work in progress. This config switch allows to
+ identify and analyze these problems. It will be removed and the
+ check permanentely enabled once the main issues have been fixed.
+
+ If unsure, select N.
+
config LOCK_STAT
bool "Lock usage statistics"
depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT