Hi Shanker,
[auto build test ERROR on next-20161224]
[also build test ERROR on v4.10-rc1]
[cannot apply to arm64/for-next/core v4.9-rc8 v4.9-rc7 v4.9-rc6]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system]
url:
https://github.com/0day-ci/linux/
On 12/29/2016 04:43 PM, Christopher Covington wrote:
+config QCOM_FALKOR_E1003_RESERVED_ASID
+ int
+ default 1
+ depends on QCOM_FALKOR_ERRATUM_1003
Also, since this can't be changed via the menu, why bother putting it in?
--
Qualcomm Datacenter Technologies, Inc. as an affil
On 12/29/2016 04:43 PM, Christopher Covington wrote:
-| Implementor| Component | Erratum ID | Kconfig
|
-++-+-+-+
-| ARM| Cortex-A53 | #826319 | ARM64_ERRATUM_826319
From: Shanker Donthineni
On the Qualcomm Datacenter Technologies Falkor v1 CPU, memory accesses may
allocate TLB entries using an incorrect ASID when TTBRx_EL1 is being
updated. Changing the TTBRx_EL1[ASID] and TTBRx_EL1[BADDR] fields
separately using a reserved ASID will ensure that there are no
During a TLB invalidate sequence targeting the inner shareable
domain, Falkor may prematurely complete the DSB before all loads
and stores using the old translation are observed; instruction
fetches are not subject to the conditions of this erratum.
Signed-off-by: Christopher Covington
Change-Id
Hi Waiman,
[auto build test WARNING on linus/master]
[also build test WARNING on v4.10-rc1 next-20161224]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system]
url:
https://github.com/0day-ci/linux/commits/Waiman-Long/futex-Introducing-throughput-
Hi Waiman,
[auto build test ERROR on linus/master]
[also build test ERROR on v4.10-rc1 next-20161224]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system]
url:
https://github.com/0day-ci/linux/commits/Waiman-Long/futex-Introducing-throughput-opti
Hi Waiman,
[auto build test ERROR on linus/master]
[also build test ERROR on v4.10-rc1 next-20161224]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system]
url:
https://github.com/0day-ci/linux/commits/Waiman-Long/futex-Introducing-throughput-opti
Hi Waiman,
[auto build test WARNING on linus/master]
[also build test WARNING on v4.10-rc1 next-20161224]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system]
url:
https://github.com/0day-ci/linux/commits/Waiman-Long/futex-Introducing-throughput-
Hi Waiman,
[auto build test WARNING on linus/master]
[also build test WARNING on v4.10-rc1 next-20161224]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system]
url:
https://github.com/0day-ci/linux/commits/Waiman-Long/futex-Introducing-throughput-
A new futex implementation called throughput-optimized (TP) futexes
is introduced. The goal of this new futex type is to maximize locking
throughput at the expense of fairness and deterministic latency. Its
throughput is higher than that of the wait-wake futexes especially
on systems with a large n
The futex_pi_state structure will be overloaded in later patches to
store state information about non-PI futexes. So the structure name
itself is no longer a good description of its purpose. So its name
is changed to futex_state, a more generic name.
Some of the functions that process the futex st
As the futex_state structure will be overloaded in later patches
to be used by non-PI futexes, it is necessary to add a type field to
distinguish among different types of futexes.
Signed-off-by: Waiman Long
---
kernel/futex.c | 15 +++
1 file changed, 11 insertions(+), 4 deletions(-)
Currently, the futex state objects can only be located indirectly as
hash bucket => futex_q => futex state
Actually it can be beneficial in some cases to locate the futex state
object directly from the hash bucket without the futex_q middleman.
Therefore, a new list head to link the futex
Two new helper functions (task_pi_list_add & task_pi_list_del)
are created to consolidate all the pure pi_state_list addition and
insertion codes. The set_owner argument in task_pi_list_add() will
be needed in a later patch.
Signed-off-by: Waiman Long
---
kernel/futex.c | 64
Two new helper functions cmpxchg_futex_value() and get_futex_value()
are added to access and change the futex value without the hash
bucket lock. As a result, page fault is enabled and the page will
be faulted in if not present yet.
Signed-off-by: Waiman Long
---
kernel/futex.c | 15 +++
A new futex_setup_timer() helper function is added to consolidate all
the hrtimer_sleeper setup code.
Signed-off-by: Waiman Long
---
kernel/futex.c | 67 --
1 file changed, 37 insertions(+), 30 deletions(-)
diff --git a/kernel/futex.c b/ke
To better understand how the TP futexes are performing, it is useful to
return the internal status on the TP futexes. The FUTEX_LOCK futex(2)
syscall will now return a positive status code if no error happens. The
status code consists of the following 3 fields:
1) Bits 00-07: code on how the lock
The TP futexes don't have code to handle the death of futex
owners. There are 2 different cases that need to be considered.
As top waiter gets a reference to the task structure of the futex
owner, the task structure will never go away even if the owner dies.
When the futex owner died while the top
The current TP futexes has no guarantee that the top waiter
(serialization mutex owner) can get the lock within a finite time.
As a result, lock starvation can happen.
A lock handoff mechanism is added to the TP futexes to prevent lock
starvation from happening. The idea is that the top waiter can
This microbenchmark simulates how the use of different futex types
can affect the actual performanace of userspace mutex locks. The
usage is:
perf bench futex mutex
Three sets of simple mutex lock and unlock functions are implemented
using the wait-wake, PI and TP futexes respectively. T
Unlike other futexes, TP futexes do not accept the specification of
a timeout value. To align with the other futexes, timeout support is
now added. However, the timeout isn't as precise as the other futex
types due to the fact that timer expiration can't be detected when
the thread is waiting in t
This microbenchmark simulates how the use of different futex types
can affect the actual performanace of userspace rwlock locks. The
usage is:
perf bench futex rwlock
Three sets of simple rwlock lock and unlock functions are implemented
using the wait-wake, TP futexes and glibc rwlock re
The TP futexes was designed to support userspace mutually exclusive
locks. They are now extended to support userspace reader/writer
locks as well.
Two new futex command codes are added:
1) FUTEX_LOCK_SHARED - to acquire a shared lock (reader-lock)
2) FUTEX_UNLOCK_SHARED - to release a shred lock
For debugging purpose, it is sometimes useful to dump the internal
states in the futex hash bucket table. This patch adds a file
"futex_hash_table" in debugfs root filesystem to dump the internal
futex states.
Signed-off-by: Waiman Long
---
kernel/futex.c | 82 +++
Unlike wake_up_process(), wake_up_q() doesn't tell us how many
tasks have been woken up. This information can sometimes be useful
for tracking purpose. So wake_up_q() is now modified to return that
information.
Signed-off-by: Waiman Long
---
include/linux/sched.h | 2 +-
kernel/futex.c|
The TP-futexes prefer writers as the code path is much simpler for
them. This may not be good for overall system performance especially
if there is a fair amount of reader activities.
This patch enables kernel reader to steal the lock when the futex is
currently reader-owned and the lock handoff m
All the TP futex lock waiters are serialized in the kernel using a
kernel mutex which acts like a wait queue. The order at which the
waiters popped out from the wait queue will affect performance when
exclusive (writer) and shared (reader) lock waiters are mixed in the
queue. The worst case scenari
The tp-futex.txt was updated to add description about shared locking
support.
Signed-off-by: Waiman Long
---
Documentation/tp-futex.txt | 163 +++--
1 file changed, 143 insertions(+), 20 deletions(-)
diff --git a/Documentation/tp-futex.txt b/Documentation
This patch adds a new document file on how to use the TP futexes.
Signed-off-by: Waiman Long
---
Documentation/00-INDEX | 2 +
Documentation/tp-futex.txt | 161 +
2 files changed, 163 insertions(+)
create mode 100644 Documentation/tp-futex.txt
v3->v4:
- Properly handle EFAULT error due to page fault.
- Extend the use cases of TP futexes to userspace rwlock.
- Change the lock handoff trigger from number of spinnings to
elapsed time (5ms).
- Various updates to the "perf bench futex mutex" microbenchmark.
- Add a new "perf be
On 12/28/2016 10:56 PM, Hui Chun Ong wrote:
Add support for the watchdog timer on PXI Embedded Controller.
Reviewed-by: Guenter Roeck
Signed-off-by: Hui Chun Ong
---
v5: Add Reviewed-by.
There is no need to re-send a patch just to add a Reviewed-by:.
Guenter
v4: Remove nic7018_stop() fro
32 matches
Mail list logo
