Re: [PATCH] Documentation: Input: Add uinput documentation

On Wed, Mar 22, 2017 at 11:54:48PM -0300, Marcos Paulo de Souza wrote: > Hi Peter, > > first of all, thanks a lot for reading this patch so quickly and to > point a lot of things to make this doc way better. > > See some notes below. thanks for all the fixes, much appreciated. just two comments

Re: [PATCH] Documentation: Input: Add uinput documentation

Hi Peter, first of all, thanks a lot for reading this patch so quickly and to point a lot of things to make this doc way better. See some notes below. On Wed, Mar 22, 2017 at 02:03:31PM +1000, Peter Hutterer wrote: > Thanks for this, I'm getting enough questions about this, so it's nice to >

Re: [PATCH] hibernation: on 32-bit x86, disabled in favor of KASLR

On Thu, Mar 23, 2017 at 1:27 AM, Kees Cook wrote: > This is a modified revert of commit 65fe935dd238 ("x86/KASLR, x86/power: > Remove x86 hibernation restrictions"), since it appears that 32-bit > hibernation still can't support KASLR. 64-bit is fine. Since people have >

[PATCH] hibernation: on 32-bit x86, disabled in favor of KASLR

This is a modified revert of commit 65fe935dd238 ("x86/KASLR, x86/power: Remove x86 hibernation restrictions"), since it appears that 32-bit hibernation still can't support KASLR. 64-bit is fine. Since people have been running with KASLR by default on 32-bit since v4.8, this disables hibernation

RE: [PATCH v7 09/11] scsi: ufs: connect to RPMB subsystem

> > On Mon, Nov 07, 2016 at 07:27:38PM +, Winkler, Tomas wrote: > > I value your opinion but I'm not responsible for inventing RPMB > > and/or its implementation storage devices (eMMC, UFC, NVMe), it's pretty > much done deal out there in the wild. > > I'm just trying to provide common API

Re: [PATCH] drm/doc: Document feature merge deadlines

On Tue, Mar 21, 2017 at 03:38:26PM -0400, Sean Paul wrote: > On Tue, Mar 21, 2017 at 04:52:28PM +0100, Daniel Vetter wrote: > > The discussion pretty much concluded without objections, let's > > document what we agreed on. > > > > Cc'ing linux-doc for the new tag in

[PATCH-tip v6 02/22] perf bench: New microbenchmark for userspace rwlock performance

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 Two sets of simple rwlock lock and unlock functions are implemented using the wait-wake futexes and glibc rwlock

[PATCH-tip v6 04/22] futex: Rename futex_pi_state to futex_state

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

[PATCH-tip v6 03/22] futex: Consolidate duplicated timer setup code

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

[PATCH-tip v6 05/22] futex: Add helpers to get & cmpxchg futex value without lock

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 ---

[PATCH-tip v6 08/22] futex: Allow direct attachment of futex_state objects to hash bucket

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

[PATCH-tip v6 15/22] TP-futex, doc: Add TP futexes documentation

This patch adds a new document file on how to use the TP futexes. In term of locking performance, a futex locking microbenchmark was written where separate userspace mutexes are implemented using wait-wake (WW), PI and TP futexes respectively. This microbenchmark was intructed to run 10s of

[PATCH-tip v6 09/22] futex: Introduce throughput-optimized (TP) futexes

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

[PATCH-tip v6 07/22] futex: Add a new futex type field into futex_state

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

[PATCH-tip v6 14/22] TP-futex: Optionally return EAGAIN for userspace locking

A performance disadvantage of TP futexes versus wait-wake futex is the fact that locking was done in the kernel for TP futexes instead of in the userspace like the WW futexes. The additional latency between when the lock was taken in the kernel and when the task returned to the userspace would be

[PATCH-tip v6 17/22] TP-futex: Enable kernel reader lock stealing

By default, the TP futexes do not have preference for either readers or writers. Most reader-writer locks allows users to decide if they want to prefer readers or writers more. This patch allows the setting of the prefer-reader mode in the val argument of the futex system call. If that flag is

[PATCH-tip v6 20/22] perf bench: Extend mutex/rwlock futex suite to test TP futexes

This patch extends the futex-mutex and futex-rwlock microbenchmarks to test userspace mutexes and rwlocks built on top of the TP futexes. We can then compare the relative performance of those userspace locks based on different type of futexes. Signed-off-by: Waiman Long ---

[PATCH-tip v6 11/22] TP-futex: Implement lock handoff to prevent lock starvation

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

[PATCH-tip v6 16/22] TP-futex: Support userspace reader/writer locks

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

[PATCH-tip v6 12/22] TP-futex: Return status code on FUTEX_LOCK calls

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

[PATCH-tip v6 13/22] TP-futex: Add timeout support

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. Like FUTEX_WAIT, the timeout value is relative to current time, not an absolute time. However, the timeout isn't as precise as the other futex types

[PATCH-tip v6 19/22] TP-futex, doc: Update TP futexes document on shared locking

The tp-futex.txt was updated to add description about shared locking support. Running the futex locking microbenchmark on a 2-socket 36-core E5-2699 v3 system (HT off) running on a 4.11 based kernel, the performance of TP rwlock with 1:1 reader/writer ratio versus one based on the wait-wake

[PATCH-tip v6 21/22] sched, TP-futex: Make wake_up_q() return wakeup count

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/wake_q.h | 2

[PATCH-tip v6 18/22] TP-futex: Group readers together in wait queue

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

[PATCH-tip v6 00/22] futex: Introducing throughput-optimized (TP) futexes

v5->v6: - Futex code changes: 1) Allow userspace locking of exclusive locks instead of just kernel locking (patch 14). This is controlled by a flag passed to the futex(2) syscall. This enables better throughput. 2) Add a reader-preferring mode to shared locking. - Futex

[PATCH-tip v6 01/22] perf bench: New microbenchmark for userspace mutex performance

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 and PI futexes as well as the

[PATCH-tip v6 06/22] futex: Consolidate pure pi_state_list add & delete codes to helpers

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 | 52

Re: [PATCH v4 4/6] drm: bridge: dw-hdmi: Switch to V4L bus format and encodings

On Tue, 2017-03-21 at 16:12 +0100, Neil Armstrong wrote: > Some display pipelines can only provide non-RBG input pixels to the HDMI TX > Controller, this patch takes the pixel format from the plat_data if provided. > > Signed-off-by: Neil Armstrong On i.MX6 we could

Re: [PATCH v4 4/6] drm: bridge: dw-hdmi: Switch to V4L bus format and encodings

On 03/22/2017 05:21 PM, Philipp Zabel wrote: > On Tue, 2017-03-21 at 16:12 +0100, Neil Armstrong wrote: >> Some display pipelines can only provide non-RBG input pixels to the HDMI TX >> Controller, this patch takes the pixel format from the plat_data if provided. >> >> Signed-off-by: Neil

Re: [PATCH v4 4/6] drm: bridge: dw-hdmi: Switch to V4L bus format and encodings

Hi Neil, On 21-03-2017 15:12, Neil Armstrong wrote: > Some display pipelines can only provide non-RBG input pixels to the HDMI TX > Controller, this patch takes the pixel format from the plat_data if provided. > > Signed-off-by: Neil Armstrong Looks fine, I'm assuming

Re: [PATCH v4 4/6] drm: bridge: dw-hdmi: Switch to V4L bus format and encodings

On 03/22/2017 05:08 PM, Jose Abreu wrote: > Hi Neil, > > > On 21-03-2017 15:12, Neil Armstrong wrote: >> Some display pipelines can only provide non-RBG input pixels to the HDMI TX >> Controller, this patch takes the pixel format from the plat_data if provided. >> >> Signed-off-by: Neil

Re: [PATCH v4 14/23] PCI: dwc: dra7xx: Workaround for errata id i870

On Tuesday 21 March 2017 03:18 AM, Rob Herring wrote: > On Mon, Mar 13, 2017 at 07:52:50PM +0530, Kishon Vijay Abraham I wrote: >> According to errata i870, access to the PCIe slave port >> that are not 32-bit aligned will result in incorrect mapping >> to TLP Address and Byte enable fields. >>

Re: [PATCH v4 15/23] dt-bindings: PCI: dra7xx: Add dt bindings to enable unaligned access

Hi Rob, On Tuesday 21 March 2017 03:13 AM, Rob Herring wrote: > On Mon, Mar 13, 2017 at 07:52:51PM +0530, Kishon Vijay Abraham I wrote: >> Update device tree binding documentation of TI's dra7xx PCI >> controller to include property for enabling unaligned mem access. >> >> Signed-off-by: Kishon

Re: [PATCH v5 untested] kvm: better MWAIT emulation for guests

On Wed, Mar 22, 2017 at 10:10:05AM -0400, Gabriel L. Somlo wrote: > On Wed, Mar 22, 2017 at 03:35:18PM +0200, Michael S. Tsirkin wrote: > > On Tue, Mar 21, 2017 at 05:02:25PM -0700, Nadav Amit wrote: > > > > > > > On Mar 21, 2017, at 3:51 PM, Gabriel Somlo wrote: > > > > > > >

Re: [PATCH v5 untested] kvm: better MWAIT emulation for guests

On Wed, Mar 22, 2017 at 03:35:18PM +0200, Michael S. Tsirkin wrote: > On Tue, Mar 21, 2017 at 05:02:25PM -0700, Nadav Amit wrote: > > > > > On Mar 21, 2017, at 3:51 PM, Gabriel Somlo wrote: > > > > > > And I get the exact same results on the MacBookAir4,2 (which exhibits > > >

Re: [PATCH] Add initial SX3000b platform code to MIPS arch

On Wed, Mar 22, 2017 at 05:38:09AM +, Amit Kama IL wrote: > Add initial support for boards based on Satixfy's SX3000b (Catniss) SoC. > The SoC includes a MIPS interAptiv dual core 4 VPE processor and boots > using device-tree. > > Signed-off-by: Amit Kama > > The

Re: [PATCH] pci-error-recovery: doc cleanup

CC MST who touched this file in last commit on it. On 03/22/2017 01:48 PM, Linas Vepstas wrote: > Hi, > > On Tue, Mar 21, 2017 at 9:24 PM, Cao jin wrote: >> Include whitespace shooting; correction; typo fix; superfluous word >> dropping. > >> >> diff --git

[PATCH] Add initial SX3000b platform related documentation to document tree

Add initial SX3000b platform related documentation to document tree: - Vendor prefix - Platform binding documentation - Interrupt Controller Unit binding documentation. Signed-off-by: Amit Kama diff --git