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authorLinus Torvalds <torvalds@linux-foundation.org>2019-07-08 16:12:03 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-07-08 16:12:03 -0700
commite1928328699a582a540b105e5f4c160832a7fdcb (patch)
treef36bb303b8648189d7b5a7feb27e58fe9fe3b9f0 /include/asm-generic
parent46f1ec23a46940846f86a91c46f7119d8a8b5de1 (diff)
parent9156e545765e467e6268c4814cfa609ebb16237e (diff)
downloadlinux-e1928328699a582a540b105e5f4c160832a7fdcb.tar.gz
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 are:

   - rwsem scalability improvements, phase #2, by Waiman Long, which are
     rather impressive:

       "On a 2-socket 40-core 80-thread Skylake system with 40 reader
        and writer locking threads, the min/mean/max locking operations
        done in a 5-second testing window before the patchset were:

         40 readers, Iterations Min/Mean/Max = 1,807/1,808/1,810
         40 writers, Iterations Min/Mean/Max = 1,807/50,344/151,255

        After the patchset, they became:

         40 readers, Iterations Min/Mean/Max = 30,057/31,359/32,741
         40 writers, Iterations Min/Mean/Max = 94,466/95,845/97,098"

     There's a lot of changes to the locking implementation that makes
     it similar to qrwlock, including owner handoff for more fair
     locking.

     Another microbenchmark shows how across the spectrum the
     improvements are:

       "With a locking microbenchmark running on 5.1 based kernel, the
        total locking rates (in kops/s) on a 2-socket Skylake system
        with equal numbers of readers and writers (mixed) before and
        after this patchset were:

        # of Threads   Before Patch      After Patch
        ------------   ------------      -----------
             2            2,618             4,193
             4            1,202             3,726
             8              802             3,622
            16              729             3,359
            32              319             2,826
            64              102             2,744"

     The changes are extensive and the patch-set has been through
     several iterations addressing various locking workloads. There
     might be more regressions, but unless they are pathological I
     believe we want to use this new implementation as the baseline
     going forward.

   - jump-label optimizations by Daniel Bristot de Oliveira: the primary
     motivation was to remove IPI disturbance of isolated RT-workload
     CPUs, which resulted in the implementation of batched jump-label
     updates. Beyond the improvement of the real-time characteristics
     kernel, in one test this patchset improved static key update
     overhead from 57 msecs to just 1.4 msecs - which is a nice speedup
     as well.

   - atomic64_t cross-arch type cleanups by Mark Rutland: over the last
     ~10 years of atomic64_t existence the various types used by the
     APIs only had to be self-consistent within each architecture -
     which means they became wildly inconsistent across architectures.
     Mark puts and end to this by reworking all the atomic64
     implementations to use 's64' as the base type for atomic64_t, and
     to ensure that this type is consistently used for parameters and
     return values in the API, avoiding further problems in this area.

   - A large set of small improvements to lockdep by Yuyang Du: type
     cleanups, output cleanups, function return type and othr cleanups
     all around the place.

   - A set of percpu ops cleanups and fixes by Peter Zijlstra.

   - Misc other changes - please see the Git log for more details"

* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (82 commits)
  locking/lockdep: increase size of counters for lockdep statistics
  locking/atomics: Use sed(1) instead of non-standard head(1) option
  locking/lockdep: Move mark_lock() inside CONFIG_TRACE_IRQFLAGS && CONFIG_PROVE_LOCKING
  x86/jump_label: Make tp_vec_nr static
  x86/percpu: Optimize raw_cpu_xchg()
  x86/percpu, sched/fair: Avoid local_clock()
  x86/percpu, x86/irq: Relax {set,get}_irq_regs()
  x86/percpu: Relax smp_processor_id()
  x86/percpu: Differentiate this_cpu_{}() and __this_cpu_{}()
  locking/rwsem: Guard against making count negative
  locking/rwsem: Adaptive disabling of reader optimistic spinning
  locking/rwsem: Enable time-based spinning on reader-owned rwsem
  locking/rwsem: Make rwsem->owner an atomic_long_t
  locking/rwsem: Enable readers spinning on writer
  locking/rwsem: Clarify usage of owner's nonspinaable bit
  locking/rwsem: Wake up almost all readers in wait queue
  locking/rwsem: More optimal RT task handling of null owner
  locking/rwsem: Always release wait_lock before waking up tasks
  locking/rwsem: Implement lock handoff to prevent lock starvation
  locking/rwsem: Make rwsem_spin_on_owner() return owner state
  ...
Diffstat (limited to 'include/asm-generic')
-rw-r--r--include/asm-generic/atomic64.h20
1 files changed, 10 insertions, 10 deletions
diff --git a/include/asm-generic/atomic64.h b/include/asm-generic/atomic64.h
index d7a15096fb3b..370f01d4450f 100644
--- a/include/asm-generic/atomic64.h
+++ b/include/asm-generic/atomic64.h
@@ -10,24 +10,24 @@
 #include <linux/types.h>
 
 typedef struct {
-	long long counter;
+	s64 counter;
 } atomic64_t;
 
 #define ATOMIC64_INIT(i)	{ (i) }
 
-extern long long atomic64_read(const atomic64_t *v);
-extern void	 atomic64_set(atomic64_t *v, long long i);
+extern s64 atomic64_read(const atomic64_t *v);
+extern void atomic64_set(atomic64_t *v, s64 i);
 
 #define atomic64_set_release(v, i)	atomic64_set((v), (i))
 
 #define ATOMIC64_OP(op)							\
-extern void	 atomic64_##op(long long a, atomic64_t *v);
+extern void	 atomic64_##op(s64 a, atomic64_t *v);
 
 #define ATOMIC64_OP_RETURN(op)						\
-extern long long atomic64_##op##_return(long long a, atomic64_t *v);
+extern s64 atomic64_##op##_return(s64 a, atomic64_t *v);
 
 #define ATOMIC64_FETCH_OP(op)						\
-extern long long atomic64_fetch_##op(long long a, atomic64_t *v);
+extern s64 atomic64_fetch_##op(s64 a, atomic64_t *v);
 
 #define ATOMIC64_OPS(op)	ATOMIC64_OP(op) ATOMIC64_OP_RETURN(op) ATOMIC64_FETCH_OP(op)
 
@@ -46,11 +46,11 @@ ATOMIC64_OPS(xor)
 #undef ATOMIC64_OP_RETURN
 #undef ATOMIC64_OP
 
-extern long long atomic64_dec_if_positive(atomic64_t *v);
+extern s64 atomic64_dec_if_positive(atomic64_t *v);
 #define atomic64_dec_if_positive atomic64_dec_if_positive
-extern long long atomic64_cmpxchg(atomic64_t *v, long long o, long long n);
-extern long long atomic64_xchg(atomic64_t *v, long long new);
-extern long long atomic64_fetch_add_unless(atomic64_t *v, long long a, long long u);
+extern s64 atomic64_cmpxchg(atomic64_t *v, s64 o, s64 n);
+extern s64 atomic64_xchg(atomic64_t *v, s64 new);
+extern s64 atomic64_fetch_add_unless(atomic64_t *v, s64 a, s64 u);
 #define atomic64_fetch_add_unless atomic64_fetch_add_unless
 
 #endif  /*  _ASM_GENERIC_ATOMIC64_H  */