diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2019-07-08 16:12:03 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-07-08 16:12:03 -0700 |
commit | e1928328699a582a540b105e5f4c160832a7fdcb (patch) | |
tree | f36bb303b8648189d7b5a7feb27e58fe9fe3b9f0 /drivers | |
parent | 46f1ec23a46940846f86a91c46f7119d8a8b5de1 (diff) | |
parent | 9156e545765e467e6268c4814cfa609ebb16237e (diff) |
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 'drivers')
-rw-r--r-- | drivers/crypto/nx/nx-842-pseries.c | 6 | ||||
-rw-r--r-- | drivers/infiniband/core/device.c | 2 | ||||
-rw-r--r-- | drivers/tty/tty_ldisc.c | 8 |
3 files changed, 8 insertions, 8 deletions
diff --git a/drivers/crypto/nx/nx-842-pseries.c b/drivers/crypto/nx/nx-842-pseries.c index 5c4aa606208c..2de5e3672e42 100644 --- a/drivers/crypto/nx/nx-842-pseries.c +++ b/drivers/crypto/nx/nx-842-pseries.c @@ -856,7 +856,7 @@ static ssize_t nx842_##_name##_show(struct device *dev, \ rcu_read_lock(); \ local_devdata = rcu_dereference(devdata); \ if (local_devdata) \ - p = snprintf(buf, PAGE_SIZE, "%ld\n", \ + p = snprintf(buf, PAGE_SIZE, "%lld\n", \ atomic64_read(&local_devdata->counters->_name)); \ rcu_read_unlock(); \ return p; \ @@ -909,7 +909,7 @@ static ssize_t nx842_timehist_show(struct device *dev, } for (i = 0; i < (NX842_HIST_SLOTS - 2); i++) { - bytes = snprintf(p, bytes_remain, "%u-%uus:\t%ld\n", + bytes = snprintf(p, bytes_remain, "%u-%uus:\t%lld\n", i ? (2<<(i-1)) : 0, (2<<i)-1, atomic64_read(×[i])); bytes_remain -= bytes; @@ -917,7 +917,7 @@ static ssize_t nx842_timehist_show(struct device *dev, } /* The last bucket holds everything over * 2<<(NX842_HIST_SLOTS - 2) us */ - bytes = snprintf(p, bytes_remain, "%uus - :\t%ld\n", + bytes = snprintf(p, bytes_remain, "%uus - :\t%lld\n", 2<<(NX842_HIST_SLOTS - 2), atomic64_read(×[(NX842_HIST_SLOTS - 1)])); p += bytes; diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c index 29f7b15c81d9..d020bb4d03d5 100644 --- a/drivers/infiniband/core/device.c +++ b/drivers/infiniband/core/device.c @@ -457,7 +457,7 @@ static int alloc_name(struct ib_device *ibdev, const char *name) int rc; int i; - lockdep_assert_held_exclusive(&devices_rwsem); + lockdep_assert_held_write(&devices_rwsem); ida_init(&inuse); xa_for_each (&devices, index, device) { char buf[IB_DEVICE_NAME_MAX]; diff --git a/drivers/tty/tty_ldisc.c b/drivers/tty/tty_ldisc.c index e38f104db174..fde8d4073e74 100644 --- a/drivers/tty/tty_ldisc.c +++ b/drivers/tty/tty_ldisc.c @@ -487,7 +487,7 @@ static int tty_ldisc_open(struct tty_struct *tty, struct tty_ldisc *ld) static void tty_ldisc_close(struct tty_struct *tty, struct tty_ldisc *ld) { - lockdep_assert_held_exclusive(&tty->ldisc_sem); + lockdep_assert_held_write(&tty->ldisc_sem); WARN_ON(!test_bit(TTY_LDISC_OPEN, &tty->flags)); clear_bit(TTY_LDISC_OPEN, &tty->flags); if (ld->ops->close) @@ -509,7 +509,7 @@ static int tty_ldisc_failto(struct tty_struct *tty, int ld) struct tty_ldisc *disc = tty_ldisc_get(tty, ld); int r; - lockdep_assert_held_exclusive(&tty->ldisc_sem); + lockdep_assert_held_write(&tty->ldisc_sem); if (IS_ERR(disc)) return PTR_ERR(disc); tty->ldisc = disc; @@ -633,7 +633,7 @@ EXPORT_SYMBOL_GPL(tty_set_ldisc); */ static void tty_ldisc_kill(struct tty_struct *tty) { - lockdep_assert_held_exclusive(&tty->ldisc_sem); + lockdep_assert_held_write(&tty->ldisc_sem); if (!tty->ldisc) return; /* @@ -681,7 +681,7 @@ int tty_ldisc_reinit(struct tty_struct *tty, int disc) struct tty_ldisc *ld; int retval; - lockdep_assert_held_exclusive(&tty->ldisc_sem); + lockdep_assert_held_write(&tty->ldisc_sem); ld = tty_ldisc_get(tty, disc); if (IS_ERR(ld)) { BUG_ON(disc == N_TTY); |