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H. Peter Anvin
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Merge remote-tracking branch 'origin/x86/fpu' into queue/x86/cpu
Use the union of 3.10 x86/cpu and x86/fpu as baseline. Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
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‎Documentation/devicetree/bindings/net/macb.txt‎

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@@ -4,7 +4,7 @@ Required properties:
44
- compatible: Should be "cdns,[<chip>-]{macb|gem}"
55
Use "cdns,at91sam9260-macb" Atmel at91sam9260 and at91sam9263 SoCs.
66
Use "cdns,at32ap7000-macb" for other 10/100 usage or use the generic form: "cdns,macb".
7-
Use "cnds,pc302-gem" for Picochip picoXcell pc302 and later devices based on
7+
Use "cdns,pc302-gem" for Picochip picoXcell pc302 and later devices based on
88
the Cadence GEM, or the generic form: "cdns,gem".
99
- reg: Address and length of the register set for the device
1010
- interrupts: Should contain macb interrupt

‎Documentation/devicetree/bindings/drm/exynos/hdmi.txt‎ renamed to ‎Documentation/devicetree/bindings/video/exynos_hdmi.txt‎

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‎Documentation/devicetree/bindings/drm/exynos/hdmiddc.txt‎ renamed to ‎Documentation/devicetree/bindings/video/exynos_hdmiddc.txt‎

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‎Documentation/devicetree/bindings/drm/exynos/hdmiphy.txt‎ renamed to ‎Documentation/devicetree/bindings/video/exynos_hdmiphy.txt‎

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‎Documentation/devicetree/bindings/drm/exynos/mixer.txt‎ renamed to ‎Documentation/devicetree/bindings/video/exynos_mixer.txt‎

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‎Documentation/devicetree/bindings/video/simple-framebuffer.txt‎

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1+
Simple Framebuffer
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A simple frame-buffer describes a raw memory region that may be rendered to,
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with the assumption that the display hardware has already been set up to scan
5+
out from that buffer.
6+
7+
Required properties:
8+
- compatible: "simple-framebuffer"
9+
- reg: Should contain the location and size of the framebuffer memory.
10+
- width: The width of the framebuffer in pixels.
11+
- height: The height of the framebuffer in pixels.
12+
- stride: The number of bytes in each line of the framebuffer.
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- format: The format of the framebuffer surface. Valid values are:
14+
- r5g6b5 (16-bit pixels, d[15:11]=r, d[10:5]=g, d[4:0]=b).
15+
16+
Example:
17+
18+
framebuffer {
19+
compatible = "simple-framebuffer";
20+
reg = <0x1d385000 (1600 * 1200 * 2)>;
21+
width = <1600>;
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height = <1200>;
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stride = <(1600 * 2)>;
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format = "r5g6b5";
25+
};

‎Documentation/devicetree/usage-model.txt‎

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Original file line numberDiff line numberDiff line change
@@ -191,9 +191,11 @@ Linux it will look something like this:
191191
};
192192

193193
The bootargs property contains the kernel arguments, and the initrd-*
194-
properties define the address and size of an initrd blob. The
195-
chosen node may also optionally contain an arbitrary number of
196-
additional properties for platform-specific configuration data.
194+
properties define the address and size of an initrd blob. Note that
195+
initrd-end is the first address after the initrd image, so this doesn't
196+
match the usual semantic of struct resource. The chosen node may also
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optionally contain an arbitrary number of additional properties for
198+
platform-specific configuration data.
197199

198200
During early boot, the architecture setup code calls of_scan_flat_dt()
199201
several times with different helper callbacks to parse device tree

‎Documentation/kernel-parameters.txt‎

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@@ -3005,6 +3005,27 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
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Force threading of all interrupt handlers except those
30063006
marked explicitly IRQF_NO_THREAD.
30073007

3008+
tmem [KNL,XEN]
3009+
Enable the Transcendent memory driver if built-in.
3010+
3011+
tmem.cleancache=0|1 [KNL, XEN]
3012+
Default is on (1). Disable the usage of the cleancache
3013+
API to send anonymous pages to the hypervisor.
3014+
3015+
tmem.frontswap=0|1 [KNL, XEN]
3016+
Default is on (1). Disable the usage of the frontswap
3017+
API to send swap pages to the hypervisor. If disabled
3018+
the selfballooning and selfshrinking are force disabled.
3019+
3020+
tmem.selfballooning=0|1 [KNL, XEN]
3021+
Default is on (1). Disable the driving of swap pages
3022+
to the hypervisor.
3023+
3024+
tmem.selfshrinking=0|1 [KNL, XEN]
3025+
Default is on (1). Partial swapoff that immediately
3026+
transfers pages from Xen hypervisor back to the
3027+
kernel based on different criteria.
3028+
30083029
topology= [S390]
30093030
Format: {off | on}
30103031
Specify if the kernel should make use of the cpu

‎Documentation/kernel-per-CPU-kthreads.txt‎

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1+
REDUCING OS JITTER DUE TO PER-CPU KTHREADS
2+
3+
This document lists per-CPU kthreads in the Linux kernel and presents
4+
options to control their OS jitter. Note that non-per-CPU kthreads are
5+
not listed here. To reduce OS jitter from non-per-CPU kthreads, bind
6+
them to a "housekeeping" CPU dedicated to such work.
7+
8+
9+
REFERENCES
10+
11+
o Documentation/IRQ-affinity.txt: Binding interrupts to sets of CPUs.
12+
13+
o Documentation/cgroups: Using cgroups to bind tasks to sets of CPUs.
14+
15+
o man taskset: Using the taskset command to bind tasks to sets
16+
of CPUs.
17+
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o man sched_setaffinity: Using the sched_setaffinity() system
19+
call to bind tasks to sets of CPUs.
20+
21+
o /sys/devices/system/cpu/cpuN/online: Control CPU N's hotplug state,
22+
writing "0" to offline and "1" to online.
23+
24+
o In order to locate kernel-generated OS jitter on CPU N:
25+
26+
cd /sys/kernel/debug/tracing
27+
echo 1 > max_graph_depth # Increase the "1" for more detail
28+
echo function_graph > current_tracer
29+
# run workload
30+
cat per_cpu/cpuN/trace
31+
32+
33+
KTHREADS
34+
35+
Name: ehca_comp/%u
36+
Purpose: Periodically process Infiniband-related work.
37+
To reduce its OS jitter, do any of the following:
38+
1. Don't use eHCA Infiniband hardware, instead choosing hardware
39+
that does not require per-CPU kthreads. This will prevent these
40+
kthreads from being created in the first place. (This will
41+
work for most people, as this hardware, though important, is
42+
relatively old and is produced in relatively low unit volumes.)
43+
2. Do all eHCA-Infiniband-related work on other CPUs, including
44+
interrupts.
45+
3. Rework the eHCA driver so that its per-CPU kthreads are
46+
provisioned only on selected CPUs.
47+
48+
49+
Name: irq/%d-%s
50+
Purpose: Handle threaded interrupts.
51+
To reduce its OS jitter, do the following:
52+
1. Use irq affinity to force the irq threads to execute on
53+
some other CPU.
54+
55+
Name: kcmtpd_ctr_%d
56+
Purpose: Handle Bluetooth work.
57+
To reduce its OS jitter, do one of the following:
58+
1. Don't use Bluetooth, in which case these kthreads won't be
59+
created in the first place.
60+
2. Use irq affinity to force Bluetooth-related interrupts to
61+
occur on some other CPU and furthermore initiate all
62+
Bluetooth activity on some other CPU.
63+
64+
Name: ksoftirqd/%u
65+
Purpose: Execute softirq handlers when threaded or when under heavy load.
66+
To reduce its OS jitter, each softirq vector must be handled
67+
separately as follows:
68+
TIMER_SOFTIRQ: Do all of the following:
69+
1. To the extent possible, keep the CPU out of the kernel when it
70+
is non-idle, for example, by avoiding system calls and by forcing
71+
both kernel threads and interrupts to execute elsewhere.
72+
2. Build with CONFIG_HOTPLUG_CPU=y. After boot completes, force
73+
the CPU offline, then bring it back online. This forces
74+
recurring timers to migrate elsewhere. If you are concerned
75+
with multiple CPUs, force them all offline before bringing the
76+
first one back online. Once you have onlined the CPUs in question,
77+
do not offline any other CPUs, because doing so could force the
78+
timer back onto one of the CPUs in question.
79+
NET_TX_SOFTIRQ and NET_RX_SOFTIRQ: Do all of the following:
80+
1. Force networking interrupts onto other CPUs.
81+
2. Initiate any network I/O on other CPUs.
82+
3. Once your application has started, prevent CPU-hotplug operations
83+
from being initiated from tasks that might run on the CPU to
84+
be de-jittered. (It is OK to force this CPU offline and then
85+
bring it back online before you start your application.)
86+
BLOCK_SOFTIRQ: Do all of the following:
87+
1. Force block-device interrupts onto some other CPU.
88+
2. Initiate any block I/O on other CPUs.
89+
3. Once your application has started, prevent CPU-hotplug operations
90+
from being initiated from tasks that might run on the CPU to
91+
be de-jittered. (It is OK to force this CPU offline and then
92+
bring it back online before you start your application.)
93+
BLOCK_IOPOLL_SOFTIRQ: Do all of the following:
94+
1. Force block-device interrupts onto some other CPU.
95+
2. Initiate any block I/O and block-I/O polling on other CPUs.
96+
3. Once your application has started, prevent CPU-hotplug operations
97+
from being initiated from tasks that might run on the CPU to
98+
be de-jittered. (It is OK to force this CPU offline and then
99+
bring it back online before you start your application.)
100+
TASKLET_SOFTIRQ: Do one or more of the following:
101+
1. Avoid use of drivers that use tasklets. (Such drivers will contain
102+
calls to things like tasklet_schedule().)
103+
2. Convert all drivers that you must use from tasklets to workqueues.
104+
3. Force interrupts for drivers using tasklets onto other CPUs,
105+
and also do I/O involving these drivers on other CPUs.
106+
SCHED_SOFTIRQ: Do all of the following:
107+
1. Avoid sending scheduler IPIs to the CPU to be de-jittered,
108+
for example, ensure that at most one runnable kthread is present
109+
on that CPU. If a thread that expects to run on the de-jittered
110+
CPU awakens, the scheduler will send an IPI that can result in
111+
a subsequent SCHED_SOFTIRQ.
112+
2. Build with CONFIG_RCU_NOCB_CPU=y, CONFIG_RCU_NOCB_CPU_ALL=y,
113+
CONFIG_NO_HZ_FULL=y, and, in addition, ensure that the CPU
114+
to be de-jittered is marked as an adaptive-ticks CPU using the
115+
"nohz_full=" boot parameter. This reduces the number of
116+
scheduler-clock interrupts that the de-jittered CPU receives,
117+
minimizing its chances of being selected to do the load balancing
118+
work that runs in SCHED_SOFTIRQ context.
119+
3. To the extent possible, keep the CPU out of the kernel when it
120+
is non-idle, for example, by avoiding system calls and by
121+
forcing both kernel threads and interrupts to execute elsewhere.
122+
This further reduces the number of scheduler-clock interrupts
123+
received by the de-jittered CPU.
124+
HRTIMER_SOFTIRQ: Do all of the following:
125+
1. To the extent possible, keep the CPU out of the kernel when it
126+
is non-idle. For example, avoid system calls and force both
127+
kernel threads and interrupts to execute elsewhere.
128+
2. Build with CONFIG_HOTPLUG_CPU=y. Once boot completes, force the
129+
CPU offline, then bring it back online. This forces recurring
130+
timers to migrate elsewhere. If you are concerned with multiple
131+
CPUs, force them all offline before bringing the first one
132+
back online. Once you have onlined the CPUs in question, do not
133+
offline any other CPUs, because doing so could force the timer
134+
back onto one of the CPUs in question.
135+
RCU_SOFTIRQ: Do at least one of the following:
136+
1. Offload callbacks and keep the CPU in either dyntick-idle or
137+
adaptive-ticks state by doing all of the following:
138+
a. Build with CONFIG_RCU_NOCB_CPU=y, CONFIG_RCU_NOCB_CPU_ALL=y,
139+
CONFIG_NO_HZ_FULL=y, and, in addition ensure that the CPU
140+
to be de-jittered is marked as an adaptive-ticks CPU using
141+
the "nohz_full=" boot parameter. Bind the rcuo kthreads
142+
to housekeeping CPUs, which can tolerate OS jitter.
143+
b. To the extent possible, keep the CPU out of the kernel
144+
when it is non-idle, for example, by avoiding system
145+
calls and by forcing both kernel threads and interrupts
146+
to execute elsewhere.
147+
2. Enable RCU to do its processing remotely via dyntick-idle by
148+
doing all of the following:
149+
a. Build with CONFIG_NO_HZ=y and CONFIG_RCU_FAST_NO_HZ=y.
150+
b. Ensure that the CPU goes idle frequently, allowing other
151+
CPUs to detect that it has passed through an RCU quiescent
152+
state. If the kernel is built with CONFIG_NO_HZ_FULL=y,
153+
userspace execution also allows other CPUs to detect that
154+
the CPU in question has passed through a quiescent state.
155+
c. To the extent possible, keep the CPU out of the kernel
156+
when it is non-idle, for example, by avoiding system
157+
calls and by forcing both kernel threads and interrupts
158+
to execute elsewhere.
159+
160+
Name: rcuc/%u
161+
Purpose: Execute RCU callbacks in CONFIG_RCU_BOOST=y kernels.
162+
To reduce its OS jitter, do at least one of the following:
163+
1. Build the kernel with CONFIG_PREEMPT=n. This prevents these
164+
kthreads from being created in the first place, and also obviates
165+
the need for RCU priority boosting. This approach is feasible
166+
for workloads that do not require high degrees of responsiveness.
167+
2. Build the kernel with CONFIG_RCU_BOOST=n. This prevents these
168+
kthreads from being created in the first place. This approach
169+
is feasible only if your workload never requires RCU priority
170+
boosting, for example, if you ensure frequent idle time on all
171+
CPUs that might execute within the kernel.
172+
3. Build with CONFIG_RCU_NOCB_CPU=y and CONFIG_RCU_NOCB_CPU_ALL=y,
173+
which offloads all RCU callbacks to kthreads that can be moved
174+
off of CPUs susceptible to OS jitter. This approach prevents the
175+
rcuc/%u kthreads from having any work to do, so that they are
176+
never awakened.
177+
4. Ensure that the CPU never enters the kernel, and, in particular,
178+
avoid initiating any CPU hotplug operations on this CPU. This is
179+
another way of preventing any callbacks from being queued on the
180+
CPU, again preventing the rcuc/%u kthreads from having any work
181+
to do.
182+
183+
Name: rcuob/%d, rcuop/%d, and rcuos/%d
184+
Purpose: Offload RCU callbacks from the corresponding CPU.
185+
To reduce its OS jitter, do at least one of the following:
186+
1. Use affinity, cgroups, or other mechanism to force these kthreads
187+
to execute on some other CPU.
188+
2. Build with CONFIG_RCU_NOCB_CPUS=n, which will prevent these
189+
kthreads from being created in the first place. However, please
190+
note that this will not eliminate OS jitter, but will instead
191+
shift it to RCU_SOFTIRQ.
192+
193+
Name: watchdog/%u
194+
Purpose: Detect software lockups on each CPU.
195+
To reduce its OS jitter, do at least one of the following:
196+
1. Build with CONFIG_LOCKUP_DETECTOR=n, which will prevent these
197+
kthreads from being created in the first place.
198+
2. Echo a zero to /proc/sys/kernel/watchdog to disable the
199+
watchdog timer.
200+
3. Echo a large number of /proc/sys/kernel/watchdog_thresh in
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order to reduce the frequency of OS jitter due to the watchdog
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timer down to a level that is acceptable for your workload.

‎Documentation/power/devices.txt‎

Lines changed: 8 additions & 7 deletions
Original file line numberDiff line numberDiff line change
@@ -268,7 +268,7 @@ situations.
268268
System Power Management Phases
269269
------------------------------
270270
Suspending or resuming the system is done in several phases. Different phases
271-
are used for standby or memory sleep states ("suspend-to-RAM") and the
271+
are used for freeze, standby, and memory sleep states ("suspend-to-RAM") and the
272272
hibernation state ("suspend-to-disk"). Each phase involves executing callbacks
273273
for every device before the next phase begins. Not all busses or classes
274274
support all these callbacks and not all drivers use all the callbacks. The
@@ -309,7 +309,8 @@ execute the corresponding method from dev->driver->pm instead if there is one.
309309

310310
Entering System Suspend
311311
-----------------------
312-
When the system goes into the standby or memory sleep state, the phases are:
312+
When the system goes into the freeze, standby or memory sleep state,
313+
the phases are:
313314

314315
prepare, suspend, suspend_late, suspend_noirq.
315316

@@ -368,7 +369,7 @@ the devices that were suspended.
368369

369370
Leaving System Suspend
370371
----------------------
371-
When resuming from standby or memory sleep, the phases are:
372+
When resuming from freeze, standby or memory sleep, the phases are:
372373

373374
resume_noirq, resume_early, resume, complete.
374375

@@ -433,8 +434,8 @@ the system log.
433434

434435
Entering Hibernation
435436
--------------------
436-
Hibernating the system is more complicated than putting it into the standby or
437-
memory sleep state, because it involves creating and saving a system image.
437+
Hibernating the system is more complicated than putting it into the other
438+
sleep states, because it involves creating and saving a system image.
438439
Therefore there are more phases for hibernation, with a different set of
439440
callbacks. These phases always run after tasks have been frozen and memory has
440441
been freed.
@@ -485,8 +486,8 @@ image forms an atomic snapshot of the system state.
485486

486487
At this point the system image is saved, and the devices then need to be
487488
prepared for the upcoming system shutdown. This is much like suspending them
488-
before putting the system into the standby or memory sleep state, and the phases
489-
are similar.
489+
before putting the system into the freeze, standby or memory sleep state,
490+
and the phases are similar.
490491

491492
9. The prepare phase is discussed above.
492493

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