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Diffstat (limited to 'kernel/Kconfig.preempt')
-rw-r--r-- | kernel/Kconfig.preempt | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/kernel/Kconfig.preempt b/kernel/Kconfig.preempt new file mode 100644 index 000000000000..0b46a5dff4c0 --- /dev/null +++ b/kernel/Kconfig.preempt | |||
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1 | |||
2 | choice | ||
3 | prompt "Preemption Model" | ||
4 | default PREEMPT_NONE | ||
5 | |||
6 | config PREEMPT_NONE | ||
7 | bool "No Forced Preemption (Server)" | ||
8 | help | ||
9 | This is the traditional Linux preemption model, geared towards | ||
10 | throughput. It will still provide good latencies most of the | ||
11 | time, but there are no guarantees and occasional longer delays | ||
12 | are possible. | ||
13 | |||
14 | Select this option if you are building a kernel for a server or | ||
15 | scientific/computation system, or if you want to maximize the | ||
16 | raw processing power of the kernel, irrespective of scheduling | ||
17 | latencies. | ||
18 | |||
19 | config PREEMPT_VOLUNTARY | ||
20 | bool "Voluntary Kernel Preemption (Desktop)" | ||
21 | help | ||
22 | This option reduces the latency of the kernel by adding more | ||
23 | "explicit preemption points" to the kernel code. These new | ||
24 | preemption points have been selected to reduce the maximum | ||
25 | latency of rescheduling, providing faster application reactions, | ||
26 | at the cost of slighly lower throughput. | ||
27 | |||
28 | This allows reaction to interactive events by allowing a | ||
29 | low priority process to voluntarily preempt itself even if it | ||
30 | is in kernel mode executing a system call. This allows | ||
31 | applications to run more 'smoothly' even when the system is | ||
32 | under load. | ||
33 | |||
34 | Select this if you are building a kernel for a desktop system. | ||
35 | |||
36 | config PREEMPT | ||
37 | bool "Preemptible Kernel (Low-Latency Desktop)" | ||
38 | help | ||
39 | This option reduces the latency of the kernel by making | ||
40 | all kernel code (that is not executing in a critical section) | ||
41 | preemptible. This allows reaction to interactive events by | ||
42 | permitting a low priority process to be preempted involuntarily | ||
43 | even if it is in kernel mode executing a system call and would | ||
44 | otherwise not be about to reach a natural preemption point. | ||
45 | This allows applications to run more 'smoothly' even when the | ||
46 | system is under load, at the cost of slighly lower throughput | ||
47 | and a slight runtime overhead to kernel code. | ||
48 | |||
49 | Select this if you are building a kernel for a desktop or | ||
50 | embedded system with latency requirements in the milliseconds | ||
51 | range. | ||
52 | |||
53 | endchoice | ||
54 | |||
55 | config PREEMPT_BKL | ||
56 | bool "Preempt The Big Kernel Lock" | ||
57 | depends on SMP || PREEMPT | ||
58 | default y | ||
59 | help | ||
60 | This option reduces the latency of the kernel by making the | ||
61 | big kernel lock preemptible. | ||
62 | |||
63 | Say Y here if you are building a kernel for a desktop system. | ||
64 | Say N if you are unsure. | ||
65 | |||